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Sunday, December 30, 2012

Meyer Lemon With Few Fruit

Q. Our Meyer lime is full of blooms.  In previous years it has yielded lots of fruit.  However, last year the blooms were abundant but all of the bloom fell off and we had a crop of one lime.  What happened? 

Meyer lemon flowers
A. This is probably Meyer Lemon. Can be difficult to say exactly but we can start to narrow it down. The major culprits are irrigation, late spring freezes and poor pollination.

            Meyer lemon is self-pollinating which means it can pollinate itself. However there does seem to be some evidence that bees will increase fruit set and the number of fruit produced. Check your fruit and see if you lots of seed. If you do have lots of seed then a lack of pollination was probably not the problem. If there were just a couple of seed then maybe the tree needs access to more bee activity.

            If we have a late spring freeze then it is possible that the flowers were killed after pollination resulting in poor fruit set. This can happen some years. If this might be the cause then try to restrict cold winter and late spring winds from directly landing on the tree. Use a wind barrier after or during bloom but don’t cover the tree and restrict bee activity.

            If the tree is not being watered evenly, a very dry and wet cycle or even one very dry period during or slightly after bloom can cause fruit drop.

            Watch how you prune. Prune right after harvest which should be December and no later than the first part of January. If you delay harvesting the fruit into the spring then this can interrupt the normal flowering and fruiting cycle.

25 Year Old Grapefruit Tree With Crystals Coming From Trunk

Readers grapefruit tree trunk with crystals coming out
Q. My grapefruit tree is about 25 years old and has always produced an abundance of fruit.  A few months ago, I noticed a crystallized substance coming out of various spots on its lower trunk.  Also, some of the leaves had developed tiny black spots, had turned yellow and had fallen from the branches. I attached photos.

            I would appreciate any help you can give me about this and what to do to stop the flow and save the tree. There are about a dozen or so grapefruit on the tree now. Are they OK to eat?

A. I posted your photos on my blog for others to see. Probably my biggest concern for your tree is it getting enough water and applied at the right times and deep enough. Frequently this type of damage is associated more with stress than anything else.

Readers grapefruit tree with crystals coming from limb
            It is also possible that this could be the result of some cold/freezing damage from a previous cold winter. In other words, I do not believe it is due to insects or an active disease. It is possible it is due to some “disease” caused from environmental stress. This type of damage can revert to an active disease problem if you do not keep the tree healthy.

            So my recommendation is to not put down any chemicals for insects or disease but to concentrate on plant health by fertilizing in the spring with a citrus fertilizer. This would be done around or prior to flowering.

            Put the fertilizer near the drip emitters or source of water so the fertilizer is pushed into the rootzone of the plant. You might want to take a look at tree fertilizer stakes but keep them at least a couple of feet from the trunk. If the source or water for irrigation is close to the trunk, move it away the same distance. 

            It is okay to start with two drip emitters for new trees but in a few years you should be adding more emitters which will allow you to spread the water more evenly under the trunk and add more water at the same time which it needs as it gets bigger. Bigger trees need more water than smaller trees regardless of the type of tree it is.

            This spring water the area under the canopy deeply and thoroughly. Add an iron chelate fertilizer when you are adding your other fertilizer as either granular, liquid or tree stakes. Like any fertilizer, it needs water to move these fertilizer salts into the rootzone.

            Prune out any dead or dying branches, crossed branches, branches growing straight up or straight down. These are unproductive and just shade the interior of the tree.

            The fruit is fine to eat as long as you have not applied any pesticides recently.

Base of Nectarine Tree Rotting I Think

Q. We have a nectarine tree trunk that we have a question about. I am attaching photos of it. It looks like it’s rotting. We were going to wrap the trunk to further protect it but we don't know if it's the right thing to do. Please view the photos when you have the time and advise us on what we should do.

Readers nectarine tree
A. Nice pictures. I will post them on my blog. It looks like there is damage to the trunk as you suggest. I would pull the rock away from the trunk about a foot. Make sure that the source of the irrigation is not close to the trunk. Put the water source a foot to 18 inches from it if possible.      Secondly, make sure you are not watering too often. You should be watering right now about every 7 to ten days but with a large volume of water when you do… enough to wet the soil to a depth of 18 to 24 inches deep on at least two sides of the tree. Three or four emitters watering this tree would be better than just two as the tree gets bigger.

Closeup of readers nectarine tree
            Pull the bark away from the damaged area if the bark pulls away easily. If it doesn’t, then cut the bark away with a sanitized knife so the damaged area is exposed and clean for healing. Keep water off of the damaged area during irrigations until it heals, perhaps around May or June.

            If the rock was put around the trunk and it keeps the trunk wet above the soil line for the first several years, you may very well encourage trunk rot or collar rot on young trees. On young trees it is important to keep mulch away from the trunk a foot or so for about 5 years or more until the trunk matures and is less susceptible to rotting. Secondly, never irrigate frequently but deeply and less often.

Irrigation Water Coming Out of Container Red After EDDHA Application

Q. I went and bought the iron chelate stuff you recommended however the instructions were not really clear.  This was for the lemon tree in the whiskey barrel with yellowing and not too many leaves.  Anyway I put about three teaspoons in the barrel and applied water.  I did not know this was going to turn the water red.  It all drained out red.  Hopefully enough stayed in to help the tree.  When should I do this again?

A. Well the water coming out all red is not a good indicator of good soil health. It also means that any fertilizer applied is going to run through it as well. I would go to foliar fertilizer applications until you can improve the soil.

            This EDDHA iron chelate that I recommend is not a good iron fertilizer for a liquid application to the leaves. Sorry. But it will be great once you improve the soil and it holds nutrients again and you apply it at the right time.

            Another method you could use would be to lift out the whole rootball out of the container if it will come out easily for you and in one piece. You can cut around the tree with a shovel and see if you can lift it out of the container. If the rootball wants to fall apart and not come out in one piece, then I would forget lifting it out and replace the soil a bit each year.

            If the tree can be lifted out, dump the excess soil left in the container, wash some of the soil from the roots and replant it in the container again after sanitizing it.

            You can inspect the roots and cut off any unhealthy roots when it is out of the container. Do not let the roots dry out when you are doing this. Before you replant it, put the tree rootball in a container full of cool but not cold water and let it soak for a couple of hours.

            Replant the tree. Stake it for a couple of months and repot the whole thing. Then apply the iron fertilizer you bought to that soil. But you will get very limited results from that iron without improving the soil. If this doesn’t make sense, email me with questions so I know what you understand and don’t understand.

Saturday, December 29, 2012

Starting a Small Backyard Orchard

Q. I'm looking to start a small backyard orchard of fruit trees next year here in Las Vegas. I was thinking of about 10 - 12 trees using the recommended varieties from your Xtremehorticulture blog.  I am still in the planning stages and would appreciate your recommendation on whether I should use bare root trees or container trees. 

Bareroot fruit tree. Notice
the "dogleg" on the trunk
where the fruit variety was
budded or "grafted" on to
an appropriate rootstock.
A. Bare root trees are only available during late winter or early spring before the leaves emerge from the tree. Bare root trees are typically small but establish very quickly if planted correctly. Directions for planting fruit trees can be found on my blog by searching “how to plant fruit trees” on the blog search engine.

            There is nothing wrong with planting container grown trees provided they have not outgrown the container. If trees are grown for too long in the container before planting, this can lead to future problems.

            Rows of the trees should run north and south so they don't shade each other. However if the trees are planted in a triangular pattern (trees in neighboring rows are offset by half of their planting distance) rather than a square pattern (trees are directly opposite each other in neighboring rows) it doesn't make much difference which direction the rows are running.

            The distance between trees in the rows depends on how big you let them get. If you elect to keep them small so that you eliminate ladders for pruning, spraying and picking then you can plant most of them as close as 10 feet apart. If you do elect to keep them smaller than this it will require more pruning effort on your part.

            Of course winter pruning will provide you with fruit wood that you can use for smoking or grilling or chip for surface wood mulch . No, this chipped wood will not cause more insects or diseases.

            On larger trees, like apples and pears, make sure you use some rootstocks that help keep them smaller. The rootstocks on my recommended list will do that for you. The distance between the rows should be no closer than 10 feet apart.

Semi or moderately intensive planting of apples on semi-dwarf rootstocks in the
former soviet union. The distance between trees is relatively close but because
they are using large scale tractors for spraying, cultivating and harvesting
the distance between the rows (the picture is between rows) is still relatively
large. This could be even more intensive (more $ per acre) if the
rows were closer together.
            If you want to get some small equipment down the rows then I would put the rows no closer than 12 feet apart and you might even consider 14 feet if you are using a small tractor or larger wagons for harvesting.

            Make sure you install your irrigation system and pre-dig your holes and amending the soil there before you begin planting. Plant directly into amended soil and thoroughly wet the soil with a hose several times after planting.

            Avoid container trees which have been in the nursery for a long period of time. Any of the nursery or garden centers will be a good place to purchase these plants if they have been recently delivered there.  

            Buy these trees just before you are ready to plant them. Don't buy and keep them at home for several days before planting. We all have good intentions but frequently these trees get neglected. When bringing them home, find a shady spot to put them until you are ready to plant. Do not keep them in the sun if temperatures are very warm or hot.

Soil in Container Growing Lemon Tree Should Be Replaced

Q. I have a small lemon tree, about 3 ft. high and 5 years old, growing on my patio in a whiskey barrel.  It currently has two lemons growing on it due to the fact that a critter ate all the others.  It has produced since the second year (up to 8 lemons) if the critter does not eat them.  However, the leaves on my little tree are very sparse.  Is this common or am I doing something wrong. I read your blog all the time.

A. Thanks for reading my blog and you will see this posting in it soon. When we grow things in containers or pots we have to be worried a bit about the soil “going bad” over time. So if you are not adding compost or trying to renew the soil in some way it will start to get depleted or it will lose its “vitality”.

            I assume you are adding some sort of fertilizer to the soil to help the tree but the addition of just a fertilizer will not be enough. Organic matter will be needed as well. It is probably best once every year or, at the most two, that you remove some of the soil from the container and add composted soil.

            It is okay if you damage some roots in the process. They will grow back. But my guess is that the soil is starting to become exhausted. If you could replace that soil with composted soil or a soil mix with a good compost in it I think you will see some improvement over time.

            Pick a spot in the container, take a garden trowel and dig two or three holes about halfway down and replace this soil. When you pick a compost, pick a good one. It will not be cheap. My guess a good one will run you about $20 or so for a couple cubic feet of compost.

            Kelloggs makes some lesser expensive composts that may be okay. Fox Farms makes good compost but it is expensive. Look for Happy Frog or others that are similar when you do this. Replace more soil the next year in the same way.

            When containers are used for vegetables or things like strawberries we normally replace the soil after a couple of plantings. Disease and insect problems accumulate and build after a few plantings. It will help if you can cover the soil in the container with a couple of inches of organic mulch that decomposes as well.  I hope this helps.

Sap Coming From Pine Tree Usually Not Borers

Readers pine tree
Q. Attached are two photos of a pine tree in my front yard.  On closer examination you will see two open wounds in the upper area of the pine tree.  Unbeknownst to me, these wounds appear to have been in existence for some time judging by the amount of pine sap around them.

            Staff at a local nursery thought the wounds might be related to little insects called borers.  However, rather than slather the wounds with tree dressing or tar, they suggested that I contact someone who was more knowledgeable than they such as the County Extension Service.  I saw your column in the paper and thought perhaps you might be able to help me.

            I did purchase Tree & Shrub Protect & Feed concentrate from the nursery as they recommended sprinkling this powder on the ground extending out to the tree line. Our pine tree is probably 20-25 feet tall and hope it isn't too late to apply some remedial/medical measures to help save it.

A. Borer damage to pines in the landscaped area of the valley is rare but worth checking out. I would pull any loose bark away from the damaged area first. If it is loose, I would want to see what is under it.

            If you the bark pulls away from the tree easily then the area under it is dead. Remove all of the loose bark and see how extensive the dead area, if any, might be. If it extends to a very large area around the circumference of the tree you would most likely see dead branches in the tree which it sounds like you don’t have.

            If there is just sap bubbling to the surface that usually indicates some damage to the wood and it exudes sap as part of the healing process. Leave it alone and let it heal just like we would any open wound we might get. Pines do appreciate an occasional deep watering unless you are doing that now.

            You can tell by looking at the canopy and how dense the canopy is. If the canopy is sparse and you can see through it easily then it is probably not getting enough water to stimulate enough good growth to keep it dense. These large trees require a lot of water, even pines. I hope this helps.

Friday, December 21, 2012

Nothing Wrong With Slight Yellowing of Mid Pride Peach Tree

Mid Pride peach with yellowing leaves
Q. Could you tell what is the problem with my mid pride peach tree? I sent you pictures.

A. You have a great selection in a mid-pride peach. Honestly, I don't see a whole lot wrong with it. The leaves are yellowish but this is not due to iron. This is actually some sunburn and discoloration to the leaves.

            The difference between iron and bleaching by intense sunlight is in the coloration of the leaf. When a leaf is discolored due to high light intensities or sunburn they tend to bronze in there yellowing. This bronzing is over the entire leaf.

            Yellowing due to a lack of available iron in the beginning stages of the leaf’s growth causes the yellowing to occur between the veins of the leaf, leaving the veins a darker green color. The term for this is in interveinal (between the veins) chlorosis (yellowing).

Closeup of the leaves on this Mid Pride peach
            As the lack of iron intensifies, the yellowing between the veins becomes more pronounced. As the iron problem worsens more, the leaf begins to scorch around the edges (it is unhealthy and cannot handle stress as well) and the interveinal chlorosis progressively gets worse. At some time, and in some species, the entire leaf may become totally yellow with scorching on the leaf margins and the veins only with a hint of green in them.

          The best type of iron chelate for us is also the most expensive one. But a little bit can go a long way. The only place I have seen this for sale in retail packages in small homeowner quantities (one pound) has been at Plant World Nursery in Las Vegas.

Whats Wrong With My Eastern Redbud Tree?

Q. Could you tell what is the problem with my eastern red bud tree? I sent you pictures.

Leaf damage to Eastern redbud growing in southern Nevada.
Eastern redbud is an understory tree in the eastern US
and does not handle harsh environments well
A. The redbud problem is pretty common with this tree and our soils and climate. Western Redbud is more tolerant than the Eastern Redbud of our conditions and would be a preferred tree for the Western United States.

            Western redbud may not be easy to find in the nurseries but it is worth a look. Another tree that might be even a better selection for you would be the Mexican redbud which looks very similar and would give you a similar impact to the Eastern redbud.

            The problem you are seeing on the leaves, scorching and discoloration, will always be a problem in this climate and soils with that tree. Eastern redbud is an understory tree in the eastern part of the United States which means it does not handle full sun very well even in the cooler parts of this country. Think of the problems it will have in our desert climate, high light intensity and alkaline soils.

            I usually encourage people to try something new but this is a small tree that you would have to babysit for many years to come even if you've found the right spot for it. I would encourage you to look for the Mexican Redbud if this is going into a desert or rock type landscape.

See what a Mexican redbud looks like

Be Careful Pruning Ash Trees

The tree on the right is ash and on the left is mulberry. The
mulberry has the ability to come back after severe pruning
due to some "hidden buds" or what can call
undifferentiated tissue that can regenerate new growth
while the ash does not and will frequently severely die back.
Q. We have two fantex ash trees that are 15 years old. They are spreading out too far. How far can we cut them back without killing them?

A. The problem with ash is that it does not have much ability to come back from cut limbs if you cut back too far and into larger wood. You should begin to structure the tree fairly early and stay on top of it but if you let it go too long and then cut it back you may have some problems.

            You can cut it back to side branches that are growing in a desirable direction but you cannot prune it back by what we call heading cuts (stubbing it back) and hoping these dead end cuts will resprout. You can cut back into second or maybe three year old wood (there are still side buds remaining that can grow) but if you cut into a limb with no buds present, it will probably die back to a major limb.

Thinning  cut, removal of an entire limb, on
a peach tree.
            So cut a branch to a crotch going in the direction you want the limbs coming from that crotch to grow. If a limb is a problem, remove the entire limb back to its source. Do not leave any stubs (dead end cuts).

            I hope this makes sense. I will put on my blog a picture of a thinning cut made removing a larger limb.

Softened Water Can Be A Problem for Landscapes and Houseplants

Salt damage to guava from saline or salty
water in the overhead irrigation (water
applied to the leaves)
Q. I'd like to soften the water in our house, or at least get some of the minerals out of the pipes. Culligan-type water softeners are supposed to release a lot of salt into the ground, which I think is harmful for the plants.  You can separate your softened water from your water for the plants but I've heard that is not cheap.  There are other so-called softeners which use calcium or potassium chloride or something else besides salt in the Culligan-type units but it's more expensive.  What should I do?

A. I am not going to talk about the pros and cons of water softened with sodium chloride versus potassium chloride for personal use. This is not my area of expertise but I can speak the subject of watering plants with softened water and your irrigation system.

            Normally, softened water starts after the water from the street has been tapped for your irrigation system. If this is done, it should not be a problem for you. It most likely would be a problem if you have tapped an irrigation system from a hose bib coming from the walls of your house. Many houses have their water softener conditioning water going to every water outlet in the entire inside of the house.
Salt applied to the ground from saline water applied through
drip emitters
            This will mean that softened water is delivered to both hot and cold faucets as well as the hose bibs you use for hoses outside the house. So if you have a water softener and you have some sort of irrigation system attached to a hose bib, then you are most likely watering outside plants with softened or saline water.

            Whenever you use a hose attached to a faucet coming from the walls of your house, then it will be carrying softened water. If you are watering houseplants from an inside faucet and you have softened water, then you are most likely watering them with softened water.

Salt damage to rose leaves from soil salts, not applied to the
leaves through overhead irrigation but salt in the soil
            Is softened water bad? Yes, it can be. If you are using inexpensive water softening salts then this is most likely sodium chloride or common table salt. Sodium is very toxic to plants and can destroy the structure of soils. Chlorides are essential to plants but in high amounts it can also be toxic.

            What to do? As you mentioned, potassium chloride is an alternative water softening salt to regular water softening salt but it is more expensive. In fact, it can be double the price or more. Potassium is a mineral contained in fertilizers and used by plants in fairly high quantities. So potassium chloride would be a better alternative for plants than common water softening salt.
Pitting of the sidewalk from water runoff
from the lawn of water containing salts

            When I installed my irrigation system, I put hose bibs in the landscape that were fed by the pressurized main line of the irrigation system. This way when I watered with a hose I was not using softened water. I avoided using water from hose bibs coming from the house.

            When I watered houseplants, I use distilled or RO water instead of water from the faucets. I mixed a very small amount of houseplant fertilizer in the water so that it had some good minerals in it. This avoided the use of softened water on houseplants which can be very toxic to most of them.

Wednesday, December 12, 2012

Buy a New Fig Instead of Propagating the Same One

Q. I have a large fig tree that gives me small green figs and that is all I get. I think not enough water as you said. I also saw the picture of cuttings to grow another tree?  Can I do that or should I buy a second tree? What about pruning? Is this a good time? 

A. I would buy another tree. They are not that expensive and you can get a different type of fig than the one you have now. Variety is the spice of life!

            But first you have to figure out what fig you have. Figs are all green when young and turn either yellow, off white, purple, purplish brown or nearly black. The white or yellow types have a more delicate flavor while the darker ones are usually more robust in their flavor. One dark one that has been given some nice reviews from homeowners in the valley is Blackjack and it is a smaller tree.

            Just make sure when you prune a fig tree, if you want two crops from it, that you leave some growth present that is last years. If you cut the tree back and take off all the growth from 2012 you will only have one crop, the main crop. If you leave some of this growth from last year you will have two crops of figs.

            You can prune as soon as the leaves drop. Figs can handle any amount of pruning you want to give them. I will be giving some pruning classes out at the orchard when I am back in Las Vegas on December 22 beginning at 9 am.

Should I Use a Systemic Insecticide on My Fruit Trees?

Q. Several weeks ago I noticed whiteflies on my dwarf orange tree. I went to Lowes where they recommended the following product: Bayer Advanced Tree & Shrub Protect and Feed. Upon reading the instructions it states: Do not use on plants grown for food but does not mention trees or shrubs. Can you please tell if this product is safe to use and if not what would you recommend?

Picture can be found at
Bayer link to this insecticide and the label
A. I cannot tell you if it is safe to use on edible crops or not. I went back and looked at the product label online. Some formulations of the product the manufacturer claims you can use on SOME edible crops including fruit trees.

            The manufacturer also claims 12 month control of some insect pests using this product. Some formulations say you can spread the granules under the tree. The tree in turn takes up this product through its roots where it spreads through the plant where this poison then gives 12 month control to pests listed on the label.

            This means that the product has spread through the entire plant systemically to provide enough of this product inside the tree to control these insects for 12 months. This also means the poison should ALSO be in other plant parts as well, such as fruit.

            These products undergo extensive testing for so-called “safety” issues that must be done before receiving a label approved by EPA. So our EPA is saying that this product has met its tolerances of “safety” (the feds do not like you to use the word “safe” in instances like this because they do not guarantee any pesticide is “safe”) and have approved this label. The product is supposed to be at such low levels in the plant that the government considers it safe to eat.

            Now, in my opinion, I would NEVER eat fruit from a fruit tree that has been treated with a systemic insecticide, period. Particularly when the manufacturer has claimed 12 month control of insects after its application! It does not make any sense to me to eat fruit from this tree in the same year it was treated with this type of pesticide. I hope this helps.

How to Prune Table Grapes

Q. I have a couple of vines of grapes. Should I cut them back so the stem is about 1 ft. high? I've been doing that and have not gotten many grapes from my Thompson plant and none from my seedless Flame. These plants are about 5 years old.

This picture was taken in the spring of 2012, about the second week of March.
You can see a grape spur in the upper right quadrant of the picture, reddish
brown, that has two leaves coming from buds . It was cut back from a much
longer stem, which grew in 2011, following the directions in this posting.
Since this grape can be spur pruned, I cut this longer stem back so that only
two buds remains on the spur. Those buds gave rise to the leaves you see.
Also coming from these buds will be growth that will form the grape clusters
or bunches. Follow this spur back to its base and you will see it connected to
a short stem, brown in color, older than the spur. This was the previous year's
spur. At the base is even older wood which has a characteristic greyish color.
A. If you continue to cut off all of last year’s (2011) vine growth, you will never have grapes. Bunches of grapes produced in 2012 come from buds on growth that was produced in 2011, the previous year. The only thing you have to do now is decide how much of the growth produced in 2012 you will leave remaining after you have finished pruning. By the way, I usually delay the final pruning of grapes until at least mid-February to avoid loss of fruit from late freezes.

Another spur which has been cut intentionally too long.
If there is damage from winter cold and the end of the
spur dies, there is enough of the spur left for it to recover.
The oldest growth at the bottom is grey. The spur on top
is reddish brown. In between is a former spur which is
brown. The spur has three buds. Bottom bud is pointy on
the bottom right of the spur. The next bud up is on the left
side where a side shoot has been cut back. The third bud is
on the top right where another side shoot was cut back.
After cold weather has passed at the mid to end of February
you would cut the spur 1/4 inch above the second bud. After
you get some experience, cut it back 1/4 inch above the
bottom bud leaving only one bud.
            Let me walk you through the steps for pruning table grapes. You can prune wine grapes this way but wine grapes should be pruned slightly different.  With wine grapes we want to be more careful to “balance” the load of fruit with the growth of the vine to get better quality grapes.

            I like to prune grapes in either one step in mid-February or a two-step process with an initial pruning of the grapes at leaf fall and a final pruning on the February date. Some people are itching to cut those grapes early and this will give them something to do. Otherwise just delay the pruning.

            There are two things to know before you begin. First, the wood where the fruit is produced is on last year’s growth which is a different color from older, nonproductive wood. It is usually more reddish. I will post pictures on my blog next week so you and others can see what I am talking about.

            Secondly, most grapes are pruned so that the amount of last year’s wood, the reddish colored wood, is only an inch or two long. But there are two table grapes that are NOT pruned like this. These are Thompson seedless and Black Monukka. These are pruned so that the remaining reddish, last year’s wood is about 12 to 18 inches long.

            When you leave just a very short length of reddish wood remaining after pruning then this is called spur pruning and this short stub of red wood is called a spur. When you leave a long piece of this reddish wood, then this is called a cane and you are cane pruning.

This is the tangle of new growth you must either remove or cut back to spurs. The new growth in the right places and spaced the right distance apart will be cut back to spurs, one or two buds in length.
            Pruning your grapes early can possibly result in no fruit production this next year in our climate. If there are some very low temperatures and strong, cold dry winds blowing across your vines after you prune it is possible to freeze back the spurs or canes and lose your crop or severely reduce it. If you delay pruning until February, you reduce that risk.

            Here is how to prune. Find the end of a stem or branch of a grape vine. Follow it until you see a place where there is a definite change in color from red to grey and the wood looks older. There is a clear separation between these two colors. This is where the 2012 growth began (red) and growth in 2011 (grey and older) ended.

            On the outside of the reddish stem you will see buds on either side. The last years red growth (on buds close to the separation of colors) is where the fruit will be produced for most grapes.

            For those grapes that require spur pruning, you can cut the reddish stem back leaving only two buds remaining. Prune ¼ inch beyond the second bud from the grey wood with a straight cut.

Another picture of one year old wood that will be cut back to either a spur
or a cane. Canes are just long spurs. Grapes like Thompson Seedless have
buds at the base of the new growth that will not produce grapes, just leaves.
So in the case of Thompson Seedless we have to cut their "spurs" extra
long so we include buds that will have fruit. Spurs are cut long enough
so that the buds that produce fruit (usually after the bottom ten buds) are
included. These extra long spurs are called "canes".
            For those grapes which should be cane pruned, like Thompson seedless, you should cut the red growth or cane so that there are ten buds remaining. Essentially it is just a much longer spur. This will leave a reddish cane in length something less than 18 inches.

            Grape vines are notorious for bleeding after they have been cut. In other words you may see water coming from the cut ends. Don’t worry about that. It is normal and will heal.

            When the vine sets small, BB-sized fruit in bunches, it is time to go ahead and remove bunches that are poorly formed or have not set berries very well or are too small.

            The remaining bunches are then pinched at the bottom, removing about 1/3 of the bunch. This increases the size of the berries that are remaining in the bunch. If your berries are small, then you did not remove enough bunches or you did not pinch the bottom of the bunch enough. Both are important.

Tuesday, December 11, 2012

Science in Action: Part III. Frankenplants

They have been called Monster plants, Frankenseeds or Frankenplants. Scientists have inserted "antifreeze" protein genes from flounder into tomatoes to protect the fruit from frost damage, chicken genes have been inserted into potatoes to increase disease resistance, firefly genes have been injected into corn plants. These are plants created in laboratories that never could have been developed by the traditional means of plant breeding.

Bizarre examples of genetically modified organisms

Plants that have been genetically engineered to resist herbicides and insects, resist freezing temperatures, produce pharmaceutical drugs and to convert nitrogen directly from the soil and developed by large multinational companies at tremendous cost are now being grown in the hopes of much larger profits. Biotechnologies of this type have evolved so quickly that the scientific community has split in the controversy and the rapid advancement of this science has left the general public and many scientists behind in ignorance and Universities scrambling for position.

The last two articles discussed how the disease crown gall was used, in the very early days of genetic engineering, to insert genetic information into plants. This ultimately led to technologies like the “gene gun” and how genes, like the one that produces the toxin from Bacillus thuriengensis (Bt), could be inserted so that crops could be protected from insects.

These two articles made it sound like biotechnology may lead to a scientifically founded Garden of Eden. To be fair, in Part III, a few of the arguments against this technology follows.

Genetic engineering is an imperfect science and not enough is known about what will happen in the long run. Many times researchers who insert genes, creating new organisms, operate with a scatter-gun approach, not knowing where the gene will end up over time or what effects it will have in the long run. Science knows very little about what a gene might trigger or interrupt depending on where it is inserted into the new host plant or animal.

Though often thought of as being precise by laypeople, inserting genes is a rather crude technology, lacking precision and predictability. The "new" gene can end up somewhere or doing something unexpected. For example, when genes for the color red were placed into petunias, this gene not only changed the color of the flower petals but also, unexpectedly, decreased the plant’s fertility and changed the growth of its roots and leaves. Salmon, which were genetically engineered to produce a growth hormone, not only grew bigger than expected and too fast but also turned green. These were unpredictable, scientifically termed pleiotropic, effects.

How do we know that a genetically engineered food plant will not produce new toxins and allergenic substances? How will the nutritional value of genetically modified foods change or will it? What will be the effects on the environment that comes in contact with these plants and on the wildlife in the food chain? Remember DDT? Examples of unexpected results from biotechnology:

·       An attempt to make potato plants resistant to sap-sucking insects has made them more vulnerable to other kinds of insect pests.

·       Crops such as maize and cotton have already been made resistant to chewing insects by adding a gene for Bt. But adding the Bt gene has led to speculation that there will be an increased attack by insects such as leafhoppers and aphids due to an unexpected drop in chemicals that deter their feeding.

·       The stems of a genetically altered, herbicide-resistant soybean were found uncharacteristically to crack open in hot climates.

All these questions are important questions yet they remain unanswered until the biologically altered plant leaves the test tube and enters the real world. The argument is that biotechnology fostered by corporations tends to ignore caution in favor of profits.

Genetically engineered organisms will disrupt our environment. Traditional plant breeding was limited to plants or animals that were compatible biologically which in turn limited the diversity of possible offspring. Breeding through gene-splicing techniques will create life forms that have never before existed, theoretically in billions of different possible combinations which can result in billions of different possible outcomes, some predictable and others not. As these new life forms escape or are introduced into the environment and enter different habitats they may do so with no environmental checks and balances.

We can look at past scenarios where biological organisms were released into new habitats with no checks and balances to see what will happen. While many have adapted without severe problems, a small percentage of them have not. These include the Kudzu vine, gypsy moth, saltcedar, Dutch Elm disease, Chestnut blight, starlings and the Mediterranean fruit fly to name a few. Whenever a genetically engineered organism is released it must be remembered that it may cause a disruption to a complex environment with pre-existing relationships that have developed over long periods of evolutionary history.

This has been characterized sometimes as a type of environmental “pollution”. But because this pollution is a “living pollution” these organisms will be more unpredictable than nonbiological pollutants. Genetically engineered products reproduce. When genetically engineered crops are grown for a specific purpose, they cannot be easily isolated both from spreading into the wild and from cross-pollinating with wild relatives.

It has already been shown that cross-pollination with “normal plants” can take place almost a mile away from the genetically engineered plantings. Three mile buffers are now being recommended in some countries. If we accept the concept that the environments and habitats have their own corrective mechanisms that allow them to “heal”, then radical changes to these environments from genetically modified organisms will require stronger corrective measures if it can be healed at all.

Ordinary pests could become "Super-pests". Much of the current effort in profit-centered, agricultural biotechnology is centered on the creation of herbicide-tolerant, pest-resistant and virus-resistant plants. The idea is to sell farmers patented seeds in the hope of increasing a company's share of both the seed and pesticide markets. The chemical companies hope to convince farmers that the new pest-tolerant crops will allow for a more efficient eradication of pests. In the case of herbicides, farmers will be able to spray at any time during the growing season, killing weeds without killing their crops.

Plants engineered to be pest resistant could become so invasive they are a weed problem themselves, or they could spread their resistance to wild weeds making them more invasive. A growing number of ecologists are concerned with "gene flow" which is the transfer of genes to weeds by way of cross-pollination. Researchers are concerned that manufactured genes for herbicide tolerance, and pest and viral resistance, might escape and create weeds that are resistant to herbicides, pests and viruses.

A Danish research team documented the transfer of a gene from a genetically modified crop to a weed surrounding the crop. This was unexpected among biotechnologists since they had dismissed this possibility even though critics had warned for years prior that it could happen.

Another fear is that insecticide-producing plants might create "super bugs" resistant to the effects of the new pesticide-producing genetic crops and that virus-resistant transgenic crops pose the equally dangerous possibility of creating new viruses that have never before existed in nature.

Putting the crowning touches on ecologists’ fears was the refusal by the insurance companies to insure against catastrophic environmental damage caused by genetically engineered organisms released into the environment.

Regardless of the criticism, bioengineered plants are here to stay. The question will remain how this new technology will be handled responsibly.

This article was previously published by the author in Southwest Trees and Turf

Thursday, December 6, 2012

Jeeesh. So You Want to Grow Magnolia in Las Vegas. Here's How.

Q. I'm probably going to be at the mercy of the stock at the local nursery this weekend. I really liked the 24 gallon Magnolia tree they had but do you think my space of 18' x 14' will be too small for a Magnolia?

Southern magnolia growing near Decatur
and Red Rock in Las Vegas
A. As long as you understand I am not endorsing the planting of a magnolia but if that is what you want, then read the following. Magnolias can get huge and so if you want to enjoy it for a few years and yank it out when it no longer does well, then go for it. You might get ten or more years before this happens.

            Do not put it close to a hot (south or west facing) wall. BUT you must plant in a hole that is three or four feet wider than the container. Mix good compost (bagged and good stuff will be expensive) half and half with the soil you take from the hole and remove large rocks (baseball sized or larger).

            Mix a fertilizer like 16-16-16 with this backfill; about one handful for each ten gallon bucket. Mix it all together and put this modified soil back into the hole surrounding the rootball of the plant.

            As you are putting this soil back into the hole, add water from a hose so it makes it the consistency of quicksand to get rid of air pockets and the slurry flows all around the root ball.

Another Southern magnolia growing near Eastern and
Harmon. Notice the dieback beginning in the top.
Roots cannot provide enough water to the tops during
mid summer and the low tolerance of this plant to
temperature and humidity extremes.
            Plant at the same level as it was in the container. Water it deeply, three times, immediately after planting and when the soil has drained each time. It will be watered after planting best with something that can deliver a lot of water because this tree will require lots of water each time it is watered.

            The amount of water should be equivalent to filling a basin around the tree with three inches of water; if it is a 15 gallon plant then apply 15 gallons of water. You don’t have to use a basin but this basin idea should give you an idea of the amount needed.

            If you use drip emitters, then you should have initially at least three emitters for a 15 gallon tree. If it is a 24 inch boxed tree, then you should put at least at four emitters. As the tree gets larger, you will need to add more emitters and more water, perhaps one or two gallons more at each application per year of growth. Big trees use more water than little trees.

            Lastly, dig out an area around the tree that will allow you to put about four inches of wood mulch in an area covering a circle, at least eight feet in diameter, around the tree. The key with this tree is the right location, soil modification at the time of planting, adequate irrigations and wood mulch under the tree.

The Truth About Deep Root Fertilization of Trees and Shrubs

Q. Is deep root fertilization a good way to fertilize our African sumac tree, purple sage bushes and the purple plum tree?  I’ve seen advertisements from some landscapers for this process.  

Where are the roots of trees and shrubs growing
in a lawn?
A. There is nothing special or magical about deep root fertilization from landscapers or done by yourself. If done properly, and many do not, the fertilizer is injected into the soil at the depth of the roots. This is usually only a few inches beneath the surface of the soil.

            Deep root fertilizer applications have made a name for themselves mostly where trees and large shrubs are growing in a lawn. By applying it beneath the surface of the lawn, high rates of fertilizer are applied without damaging or killing the lawn or causing the lawn to have dark green spots of tall grass where the fertilizer is injected. The rates of fertilizer applied is quite high so the “saltiness” of the fertilizer (all fertilizers are salts of some sort) would normally kill the grass if that fertilizer is applied directly to the lawn.

These are the brown spots in your lawn that will occur
if you drop fertilizer on one spot or place it too shallow
under the lawn. It should be 6 to 8 inches under the surface.
            Also, lawn grasses are fertilizer “hogs”. Because of their fibrous root system they take fertilizer, nitrogen in particular, easily and quickly from the soil thus robbing it from deeper rooted trees and shrubs. By placing a complete fertilizer (one containing all three elements, nitrogen, phosphorus and potassium) several inches beneath the soil surface, it places the slower moving phosphorus and potassium right at where the roots are feeding.

            Commercial companies will usually use a liquid fertilizer and inject it with what is called a “soil needle” or deep root feeder. This is a probe that is connected to a tank on the back of a truck containing a fertilizer solution. A hose comes from the tank through a pump and, under high pressure, the liquid fertilizer is injected into the soil.

Granular fertilizer placed next to a bubbler in wood mulch so
the fertilizer will be moved to the roots by the water
coming from the bubbler.
            Real fancy units will allow the operator to squeeze the handle on the injector (a probe with holes in it to allow the fertilizer solution to injected into the ground) and inject a precise amount of fertilizer solution with each injection. The operator can inject the soil in dozens of places under the tree very quickly an be on his or her way.

            You will know if they are doing it correctly by how deeply they push the injector. If they push it too deeply, the fertilizer will be placed beyond the plant roots and a large amount will be wasted. If they don’t push it deep enough and it is in a lawn, then you may have burn spots in the lawn. Burn spots are usually less of a problem in the winter months.

            You can do deep root fertilize your own trees and shrubs by using tree and shrub fertilizer stakes and pounding them into the soil beneath the soil surface a few inches. You can also do it by irrigating the lawn and, while the soil is still moist, pushing a shovel into the soil in spacings about two feet apart under the canopy.

Fertilizer stake. The plastic cap is placed over the fertilizer
stake so that it does not shatter when pounded into the
wet soil under a tree near the source of water.
            The shovel is pushed into the soil all the way, pushed forward so that the slit cut by the shovel is open, and dropping some fertilizer into the open slit. You then pull the shovel out and push the slit closed with your foot. Irrigate immediately after you are finished.

            If your trees are in a desert landscape with drip irrigation then the whole idea of deep root fertilizer comes into question. When trees and shrubs are watered by drip irrigation then I would question whether deep root fertilizer applications are necessary. All the fertilizer will be “pushed” by watering from the drip emitters.

            Roots of trees and shrubs in a rock or desert landscape will not grow like they would in a lawn. Instead, with drip irrigation, roots grow profusely near the emitters and do not go “searching” for water or grow toward water. They are not psychics.

            With drip emitters is best to drop your fertilizer in slits next to the emitters or use tree fertilizer stakes at the emitters.

The Birdsnest Mushrooms in Your Mulch - Kids Will Love Them!

Reader's "pods found in the garden. All of these might nearly
fit on a quarter to give you a rough idea of their size.
Q. I figured I can't let more than three months go by without pestering you with a question! Attached are two photos of some mystery pods I found in the garden when doing some clean up. One is with the pods closed, and the second is with them open and with what appears to be small black seeds. Any idea what this is?

A. These are not pods at all but what is called birds nest mushrooms. These do look like tiny little pods with black seed like things inside them. Like other mushrooms or saprophytic (feed off of dead things) fungi they “feed” of off decaying organic matter in the soil. We can see these fairly commonly in compost heaps, decaying mulches or other places where organic waste is decomposing. They are interesting and kids love these little things.
Unopened or just opening "pods" of the reader

            Nothing to worry about. They feed off of DEAD plants so no harm to living plants or you. They are decomposers so they help to break down litter on or in the soil after or during a warm wet period. I attached a fact sheet from Texas A and M on this interesting form of plant life. I will post your pictures on my blog for others to see them.

Science in Action: Part II. Designer Plants

Designer Plants
Robert Ll. Morris

Genetic engineering has changed commercial plant breeding forever. In years past we always thought of obtaining new plants by simple breeding and hybridizing. But to get for instance elms resistant to elm leaf beetle or turfgrass resistant to Roundup these plants had to be permanently changed in ways that simple breeding and hybridizing had not been able to accomplish. The major limitation was that the plants had to be relatively close in their evolutionary history so that a transfer of new information from one plant to another by traditional breeding techniques could occur.

All that has changed with genetic or bioengineering. Over the last twenty years scientists have discovered that all living organisms have genetic information that is interchangeable, even between plants and animals. Unlike traditional breeding, bioengineering has made it possible to select exactly the traits desired from nearly any living organism and insert them into a plant and create a genetically modified organism (GMO).

In Part I we talked about how the bacterial disease, crown gall, played a role in bioengineering by providing a biological model for scientists to use to insert desirable genetic information permanently inside plants. It was known that the crown gall organism, a bacterium, could infect a plant and insert its own information causing the plant to do something it normally would not do. In the undesirable case of the crown gall disease, produce a tumorous swelling of plant tissue that housed and protected the disease.

More on Crown Gall Disease Organism

Scientists realized that packets of new, desirable genetic information might be inserted into plants following the same method that crown gall bacterium used. Early in the development of this technology the crown gall bacterium, modified with desirable genetic information, was used as the vehicle for transferring genetic information to plants. The crown gall model of gene insertion eventually led to the development of new more efficient technologies like “gene guns” which could “shoot” new information inside of plants.

Terms like “gene splicing”, which scientists use to recombine genetic information inside plants in an attempt to bioengineer a new organism with more desirable traits, results in “transgenic organisms”. This is a term that can be daunting at first until it is realized that it just means an organism that was altered or changed as a result of new genetic information which was purposefully inserted by some method.

More on Gene Splicing

Transgenic organisms usually have some sort of benefit passed on to it from genetic engineering resulting in an economic benefit to the horticulturist and ultimately the consumer. These might be new plant traits such as improved resistance to plant pests like viral yellows or ringspot diseases, acquired resistance to pesticides such as the Roundup Ready® line of crops, some dwarfing characteristics in agronomic crops like wheat, the preservation of food flavors such as in Flavr Savr©  tomato lines, and improved resistance to insect pests by inserting genes from biological organisms that produce toxins poisonous to insects such as the bacterium Bacillus thuriengensis (Bt).

Bt pesticide sprays for controlling insects have been available to commercial applicators and homeowners as a form of “natural” or “biological” pest control since the early 1960’s under a variety of different names. The first release of a Bt spray had a very narrow range of insects that it would control. Larvae of moths and butterflies with an alkaline gut pH and that fed largely on leaf surfaces were the only targets. This narrow range in pests that it controlled was both good and bad. It was good since it was very safe for humans and other animals that weren’t larvae of moths and butterflies such as beneficial insects. It was bad since it controlled such a narrow range of insects and these only in their larval stages.

We now recognize this particular strain of Bt as the variety kurstaki. Since the 1980’s there have been 50 strains of Bt developed that are specific to not only moth and butterfly larvae but larvae of other insects such as the elm leaf beetle (Bt var. tenebrionus), fungus gnats (Bt var. israelensis), and a wide range of agricultural pests including beetles. All the different Bt’s had the same basic scenario however; the susceptible juvenile insect eats plant foliage that has the bacterium on its surface, Bt spores are ingested by larvae, the spores grow and reproduce inside the insect producing toxins, toxins paralyse the digestive tract of the larvae causing it to cease eating, insect death. Death can range anywhere from a few hours to 5 days after ingestion. This depends on the amount of Bt ingested, the size and variety of the larvae and variety of Bt used for control.

Bt became popular in the past because it had some distinct advantages over other pesticides: it had a low hazard to humans; there was no waiting period from time of application before re-entering the field; different strains of Bt didn’t harm beneficial or non-target insects; insects that died from Bt were not dangerous to predators; Bt was not known to cause injury to plants on which it had been applied and was not considered harmful to the environment; and, little or no insect resistance had been reported.

More on Bacillus thuringiensis or Bt

The major problem with Bt applied as a pesticide was its lack of persistence in the environment (sunlight and rain shortened its life) and it had to be eaten by the insects to work and only the larval stages of the insect were susceptible. Multiple applications needed to be applied with just the right timing or its chances of success were limited.

            But what if the Bt toxin could be inserted into the plant? The toxin would always be present so timing was not a problem. Persistence was not a problem since the plant protected and even produced the toxin. To insert the Bt toxin gene (lets call it X gene) the scientists first identify the right Bt. Next they isolate the X gene and remove it from the Bt bacterium. They then attach a second gene, a gene that provides resistance to a toxic chemical such as an antibiotic or herbicide, to the Bt gene. Lets call the second gene the Y gene. The X gene, with the attached Y gene, is inserted into plant cells. Any plant cell that has the toxic X gene now is given resistance to an applied toxic chemical due to the presence of the Y gene.

Researchers then multiply the plant cells in the presence of the antibiotic or herbicide and kill all cells that do not have the Y gene. Because the X and Y genes are attached, the resulting cells will contain the Bt toxin. These genetically transformed plant cells are then grown into whole plants by a process called tissue culture. The modified plants produce the same lethal Bt protein produced by Bt bacteria because the plants now have the same gene.

The insertion of the toxic genes from Bt into plant lines so that plant itself becomes toxic is under quite a bit of controversy. First and foremost is that growing plants that continually have the Bt toxin present increases the chance that insects feeding on these plants may become resistant to the Bt gene.

There is some recent research that has demonstrated that this has already happened. Problems arise primarily because the Bt toxin is always present through the plants life cycle and that it is in all plant parts. Because susceptible insects must ingest the Bt toxin to be poisoned, genetically engineered cells could be directed to plant parts that only the target pest will eat or at certain times of the year. Scientists have been working on a Bt gene that will “switch on” in plant parts that are green (leaf tissue) or “switch off” in other plant parts that are not green (flowers, pollen and seed). Plants receive genes with a genetic “promoter switch” that results in production of the Bt toxin only in certain plant parts.

My article was previously published in Southwest Trees and Turf