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Sunday, July 1, 2012

What are Those White Fuzzies on My Plants?



White fuzzies on bell pepper.
Q. I have one coreopsis among many that also is showing the white fuzzy on the stem. In addition there are black specks on the leaves. Same thing, two different stages, or two different problems? The coreopsis in general is sickly, and I see that something is eating the leaves. Planted around the edge of the watering basin (5' in diameter) of an old peach tree. Watered by filling the tree basin twice a week. I have not sprayed with anything.

A. Those are the egg casings of a couple different critters .  One can be one of the Sharp Shooters (not the ones that vector Oleander Leaf Scorch/or on grapes Pierce's Disease - Same bacterium different stains but all carried by the Glassy Wing-, Smoke Tree-, and Emerald- Sharp Shooters)  . . .
These Sharp Shooters are kind of cool when if standing under a tree with the sun on the other side of the tree i.e. back lighted you can see the raining of fluid from the Sharp Shooters . . Sometimes if you stand under a tree you can feel the moisture raining down . . Just try and remember it's bug pee . . Another critter with similar egg cluster is a close relative that passes through our lives nearly non-detected except for the egg casing . .
White fuzzies on Coreopsis

They tend to show up on just a few plant stems and a few more plants on their petioles .  . Most think it's a fungal infection . . The Sharp Shooter impact to plants is negligible so in this case the education value far outweighs any possible impact to plants . .

-Terry Mikel

Reader Had No Luck Using Spinosad and Soap and Water on Leafhoppers on Grapes

My picture of grape leaf with leafhopper poopoo
(the black specks)
This came in from a reader regarding his lack of luck using Spinosad or soap and water sprays for leafhopper control in grapes.

I want to share my experience using the diluted spray of a wettable clay compound to prevent leaf hopper damage to our grapevines. Last year our grapevines were greatly infested with leaf-hoppers. Repeated applications of insecticidal soap and spinosad could not make a dent in the insect damage.

This year, we began early, when there were about 10 leaves on each arm of the vine, trying a natural wettable clay powder called Surround, that leaves a white coating of clay on wherever sprayed. We flocked the leaves both sides as best we could in a manner reminiscent of Christmas tree flocking, and left a white residue on both sides of the leaves that was intended to make leaf hoppers unable to damage the leaves through the clay barrier. The reapplication of spray becomes more difficult as the season proceeds and requires a definite commitment of the gardener to persist.

Surround application to pear, turns the
foliage white from the clay
We can now say that for all our efforts, leaf hopper damage is much the same as last year. But there are two positives. First, the grape skeletonizer eggs don’t have a chance as they are dead abornin’. Second, the birds who are inclined to peck every last one of our figs, do not peck the whitened figs. So at last we can have some tree-ripened fruit.
-Harrison
Thanks Harrison. I would like to post your observations. On the other hand I have had luck with Spinosad on leafhoppers on grapes for several years in a row. It does not totally wipe them out but it did reduce the numbers considerably over previous years. And we never really saw damage to the berries themselves with the leafhoppers they were just a nuisance.
As far as Surround goes I have used it at the orchard for a couple of years to reduce sunburn on apples and never really got it to work well and it was a pain to apply so gave up with about half of a 50 lb bag left.

Queen Palms Must Be Treated Like Queens If They Are to Survive in the Desert

Queen palms planted in front of a casino dead after winter
freeze in Las Vegas
Q. Hi, I'm a follower of your blog and I have two questions if you don't mind answering them.  First, what is your overall opinion of queen palms in the Las Vegas climate?  It seems like every winter they struggle but eventually come back in the late spring, early summer. 

My second question is, what is the best water requirement for a 15 gallon queen?  Is it best to have a few 4 gallon emitters over an hour time or many 1 gallon emitters over a few hours?  I'm just curious what is the best way to water them.  Also do I water every other day or 3 days a week in the summer months?  I would greatly appreciate a response!  Thanks in advance


A. Queen palm is not the best choice in palm trees for our climate in general. This is a harsh environment for them particularly our very low winter temperatures, our lack of humidity, strong dry winds and poor soils. Once we recognize this then we can begin to address the situation and determine if a queen palm is a good choice for us and what we will have to do to get it to work here. The absolute worst thing you can do with a queen palm is put it directly into a very our harsh climate, fully exposed to the elements and not amend the soil or amend it very little.
            If you were to plant it in our desert environment then you would try to find a place for it out of strong winds, protected from extreme winter low temperatures and amend the soil adequately at planting time and use organic surface mulches that break down and improve the soil over time. This is hard to find here in Las Vegas so planting them here will have poor results unless you can find this ideal micro environment; not impossible but hard to find.
Queen palm planted in rock/desert landscape and yellowing
or chlorotic due to poor soil conditions

            Palms are high water users in the small space that they occupy. So water does not have to be applied over a large area but should be applied in an area equal to at least half of the spread of their canopy. The water should be applied so that it soaks the soil down to about 24 inches each time you water.
            The soil should never go totally dry and surface mulches will help in this. Also planting understory plants that require more frequent watering will also help. How many gallons does a 15 gallon palm require? About 7 to 10 gallons each time you water or about half to 2/3 of the volume of the container (even though a 15 gallon container does not hold 15 gallons).

            Four emitters would be good in a square pattern about a foot from the trunk. How many minutes (or hours) should you run it? I don’t know. Depends on your emitters. If these are 2 gallon per hour emitters then 60 to 75 minutes.
            The other question to answer in watering is how often. You are asking about a one day difference in your watering. I really cant tell you that without knowing more about your soil and how much water it holds. If it drains freely and doesn’t hold much water then every other day now. If this is a soil that can hold a bit more then every third day would be good.

            Why don’t you try using a houseplant soil moisture meter to help determine the how wet the soil is before you irrigate. Once you do this a couple of times it will become more intuitive about how often to water.

Potatoes Look Dead and Never Bloomed


Q. Thank you for all your help! New problem: my potatoes are all about dead. They looked great in the Spring, but they never even bloomed. Is there any hope? Why did they die? I have them in a raised bed.
Potato tuber forming from underground shoot (stem)
coming from the potato plant stem

A. It is really hard to say what is going on without more information but let me run down the ideal situation for you and maybe you can figure it out. If I were to take a guess, I would guess it may have to do with your soil or watering or both. The ideal soil is a sandy soil and not a heavy clay type of soil. Sandy soils allow for good tuber production, easy harvesting, fewer disease problems which attack the roots and irrigations that are easier to manage.

Potatoes growing with drip irrigation
Potato plants can be started by quartering your favorite potato tuber with a clean knife and letting the cut tubers heal for 48 hours inside the house or in a cool area. You can also dust the tubers with a fungicide if you like. The other way, a preferred way, is to buy potato “seed” (which is really small potato tubers or tubers that have been cut and allowed to heal) that have been officially “certified” to be free of diseases and viruses.

Of course this is more expensive but reduces the chances of disease in your potato plants.
Potatoes plants (and tubers for that matter) are sensitive to freezing temperatures. For this reason we plant potato “seed” very soon after we are fairly certain spring freezing weather has passed. This can be any time from early to the end of March in our climate. Planting later than March will probably not result in very good production. Potato seed is planted about two to three inches below the soil and about twele to 18 inches apart. If the variety of potato is a real vigorous grower then space them further apart (18 inches).

A better way is to sprout the seed before planting. This helps to get them off to a good start. You would sprout the seed in a shallow box in the house in a room that is warm and has plenty of light. Once the seed sends up sprouts that are a few inches long, plant them carefully in the prepared soil about two inches deep and about twelve plus inches apart. Water them in thoroughly. Make sure you have put a good high phosphorus fertilizer in the prepared bed and the soil has been composted well.

Once the potatoes have shown some good growth to maybe 12 inches in height, pull the composted soil around the plants so that only a few inches of potato plant is peeking above the soil. This is called hilling and is needed so that the potato stems send out side shoots where the potatoes will form. If you don’t do this you probably won’t have very many potatoes.  Keep hilling around the potatoes every couple of weeks as they keep growing above this soil that has been pulled around the stems. Keep the soil moist or mulch the potatoes so they don’t get knobby. I hope this helps.
You can harvest any time tubers have formed. Just carefully dig down around the stems and feel around for tubers, cut and remove.

Something's Eating My Basil and It's Not Me!

Q. Sir ,this picture shows my  chewed "genovese " basil ,if you enlarge the picture you will see small insects resembling those who ate the leaves of the vine .
What can I do without poisoning my basil?
Thanks for your answer.
Luciano's Genovese basil with damage
Regards ,Luciano

A. I enlarged the picture gradually up to 800% but still could not make it out. The feeding looks more like a larger pest such as root weevils or caterpillar (larvae of moth) to me. Smaller insects would be more likely holes throughout the leaf rather than on the edges of the leaves.  Soap and water sprays have to come in contact with the insect.

            Organic types like Bt (Dipel or Thuricide) or Spinosad will focus a lot on the caterpillar types and give you some overnight protection if done at dusk and would be a good first effort. Follow label directions. If this does not work then I would move toward one of the pyrethrum or pyrethroid products with vegetables or herbs on the label. Check the ingredients for these products.
            Sevin might also work but apply only at dusk since it is lethal to bees which will be visiting basil a lot unless you keep the flowers clipped off. Spinosad also is tough on bees so use it only at dusk.

Avocados High Risk in Las Vegas Area But If You HAVE to Plant One....



Q. Do you have recommendations/suggestions for new avocado and lime tree plantings for Las Vegas? I currently have a Meyer lemon tree which is doing great.

A. I don't like to recommend lime or avocado for this climate, particularly avocado, unless you have a very warm spot in the landscape that can give off a lot of winter warmth and protection from winter winds.
            These plants are very tender during the winter here and the chances of losing them due to winter cold is extremely high. That being said, if you decide to move ahead with a lime then any of the limes would be a good choice depending on your preference. Rangpur and red limes, although cold hardy, are not limes at all but could be used as a substitute. To my knowledge there is little difference in the true limes abilities to make it through the cold here so that would not be a consideration.
            As far as the avocado goes, I would select a smaller selection to give it a better chance of surviving. Make sure the rootstock is also cold tolerant or you could lose the roots while the top did not freeze. Here are some recommended cold hardy varieties from a Texas website: http://toptropicals.com/html/toptropicals/articles/fruit/varieties_avocado.htm
Cold hardy varieties:
Brazos Belle: Produces medium-large, purple-black long fruit. Season: October-November.
Fantastic: Produces green, paper thin skin, supposedly the most most cold hardy of all. The fruit has a creamy texture.
Joey: Selected by Joey Ricers in Uvalde, Texas (just outside of San-Antonio). Produces medium size, egg shaped purple-black fruit. It has excellent flavor. Heavy bearer. Season: September-October.
Lila: Produces medium size, green fruit. Season: September-October. Don't confuse this variety with Lula, which is popular Florida variety and commonly used for rootstock. (Lula is cold hardy to 25F)
Poncho: Produces medium to large green fruit. Cold hardy to 15F

Pepper Tree Losing Its Leaves and Apricot Dropping Its Fruits

This is normal fruit drop in apricot. The fruit was mature
and ready to be picked and a good wind came along
and blew them off of the tree during the night.

Q. Our Pepper tree is losing it’s leaves and they are dropping like crazy. Can you tell me what I can do or is this normal this time of year? Also the fruit is dropping off apricot tree.

A. Leaf and fruit drop can be from very similar causes, usually some form of stress. This stress can come from temperature extremes, irrigation and soil moisture extremes or wildly fluctuating soil moistures. Unlike leaves, for fruit to stay on the plant or tree the flower needs to be pollinated and the environment should be fruit-friendly.

            Even though flowers are modified forms of leaves for fruit to develop then it must include the transfer of pollen from male parts of a flower to female parts of the flower. During this transfer it is best done by insects like bees in those trees and plants requiring pollination by insects (most fruit trees and vegetables).
            During pollination (which can cover a period of a couple of weeks in cool weather because the flowers don’t all open at once) it is best if the weather is friendly to pollinators (good temperatures, good humidity and normal winds) as well as pollination. So when the flowers are open you hope for warm weather free from rain and storms. When these conditions vary further and further from ideal then the amount of fruit set may be diminished.
Early almond drop in May due to lack of pollination. The
yellow almonds have not been pollinated so no nut has
formed and the whole nut drops from the tree two months
before harvest.
            Temperatures after fruit set can play a big factor as well. If temperatures drop really low after fruit set then this can cause fruit to drop early. Some fruit can start to develop from the flower even though it is not pollinated but this fruit will drop from the tree, usually turning yellow first before dropping. The bees may have missed this flower but the flower starts forming the fruit anyway.
            Without pollination many fruits cannot develop more than just its juvenile stage and then drop. The fruit tree thins itself in this manner but not enough for our pleasure. This can be normal but should not be all of the fruit. This is called “June drop” which happens in our climate earlier, sometime in late April or early May usually.
Plum fruits, if they do not get pollinated, will grow for awhile
but eventually yellow and drop from the tree early while
pollinated fruit (green here) will continue on to maturity.
            In the case of your apricot see if it is natural thinning; small fruit yellow and drop. There should still be some fruit remaining. By the way some apricots do need pollinator trees. I do not know what variety you have but Tomcot, Perfection and Rival are three that might need a pollinator. If it set in previous years then it is a problem that occurred this year such as late freeze, poor conditions for pollination when the flowers were open, irregular watering and some others. Hopefully it is just June drop and you still have plenty of fruit left.

            With your California pepper it is most likely irregular or having a streak of hot weather that the plants were not prepared for. Make sure if you get hit with hot weather out of the norm to run them through an irrigation cycle ahead of schedule.

Plum Tree Loses Its Leaves After Planting


Q. We recently had our back yard landscaped. We had a plum tree planted in the one corner. It did okay for a few days and then it lost all it's leaves!!! It was getting water. A few sprouts from the base are coming up but nothing else. Is it dead or just been shocked from the transplant?


A. I will have to speak in generalities since I have so little to go from.  Usually when a tree is planted and it loses all of its leaves very quickly it is due to some sort of shock. 

            These shocks can come from leaving the black plastic container in full sunlight for a day where the sun can cook the outside temperature of the container and a portion of the soil in the container to 170° F in our climate; missing an irrigation in the container when it needs it can cause leaf drop in a matter of days; planting a landscape tree from a container into hot or very dry soil can cause root dieback and leaf drop; growing a tree in partial shade and moving it to full sun can cause leaf drop; planting the tree too deeply may cause leaf drop; planting the tree too shallow with the roots exposed can cause leaf drop; putting fertilizer too close to the trunk or roots can cause leaf drop; and there are probably more that I can’t think of right now. 
            All of these can be termed transplant shock.  The more careful you are in planting trees and shrubs the less shock the plant will have.  If the tree has lost its leaves during severe summer heat than the prognosis is not good and you will probably have severe dieback. 
            It will be your call as to whether you want to keep the tree or not.  If your growth is coming beneath the graft or dogleg on the trunk at the bottom and pull the plant out and replace it.  Here is how to minimize transplant shock. 
           Have the whole pre dug before you bring the plant home from the nursery.
           Plant the tree or shrub immediately when you get home.
           Never plant into a hot hole or dry hole.
           Plant in the early morning hours not during the day when it is hot or windy.
           Remove the plant from the container and get it into the hole is quickly as possible.
           Never remove the plant from a container by pulling on the stem and the yanking it out.
           Immediately stake the plant after planting making sure the state is driven soundly into the hard soil beneath the planting hole
           Make sure you plant the tree or shrub the same depth that it was in the container.
           Dig the hole deep enough to accommodate the root ball of the plant and no deeper.  Taking the hole wide is better than taking a deep.
           Water the plant in the hole immediately after planting and use a hose for the first week of watering, not the drip system or irrigation system for the initial watering.

My Beautiful Italian Cypress Was Butchered By A Tree Service


Q. HELP! My 25 year old beautiful Italian Cypress have been butchered by a tree service hired only to top them. How can I save these once beautiful trees. I am sick. I have been hosing them down every morning and deep watering them also.They have many brown areas that have been chopped to the limbs. There is a lot of green but, they do not look well. I can take a picture and send it if it will help garner some advice.
Overwatering or overfertilizing or both
can cause excessive growth and "floppiness"
A. You can send me a picture but frequent water may in fact be hurting the tree. Go back to deeper (12 to 18 inches deep) watering occasionally. Right now perhaps not any more often than once a week at the most.
            You can also try to apply some fertilizer lightly, one application only. It does you no good to fertilize over and over. It will put on new growth mostly now and slow down as the summer is concluding.

            If the landscape company has cut back the stems into bare wood it is very possible it may not recover. If it does recover because they did not cut too deeply the recovery will be slow. Unfortunately this is a problem when they prune with hedge shears which is ridiculous. 
            Frequent watering may cause some succulent growth to occur which will not be sturdy and this growth will be “floppy”.
            I wish I had better news but you will have to wait and see how the plant responds. But in the meantime water and fertilize normally; water once a week and fertilize once or maybe twice this season. That’s all you can do. Let me know how it turns out.

Living Windbreaks Use Water - A Major Concern in the Desert


Q. We just moved from Las Vegas to Pahrump We bought a home on an acre of land - I'd send a picture but - to be honest  - its just bare high-desert land As far as we know Pahrump is considered Zone13 (Sunset). We would like your advice on trees for wind barriers. We have been told by locals that there are several pine trees that would make a good wind barrier. Judging by the look of the town, most properties have planted the pines around the perimeter of their properties.
After reading SNWA desert planting ideas and other high-desert websites, we thought we would start with the pines and then layer from there (inward) For example:pines fruit or other shade trees large bushes or grasses edible and low bushes finally, low growing plants.  We want to encourage birds, hummingbirds and butterflies and we will add raised beds for veggies.
Could you give us your advice on the types of pines and other trees that would grow in this area. Could you please comment on the layering plan or give us some indication which direction we should head?

A. I would refer you to a fact sheet I wrote a couple of years ago which can be found at http://www.unce.unr.edu/publications/files/ho/2006/fs0688.pdf

It basically says that the windbreak will affect an area downwind equal to about five times its height. Windbreaks need to be multilayered when possible with a combination of trees and shrubs. A variety of plants, not just one kind, is more desirable. The biggest mistake I see done in Pahrump is putting a big line of trees right on the border of their property. It just does not make any sense to me. If they need a fence there is a lot of things you can build that don't require water. If it is a windbreak then it is too far from the living area to be very effective. You need to answer the questions where does the wind come from that you are trying to stop. What time of year is it a problem.

Design your outside living area first. Then go ahead and place your plant materials for screening, visual barriers and windbreaks. Windbreaks integrated into your landscape can use smaller plants. Remember big plants use more water than little plants and if you put a whole bunch of trees on the perimeter of the property what good does that do except use up a bunch of water unnecessarily. Plants need to be concentrated near living areas and they need to be part of the outside living area, usually defining the "walls" and "ceilings" of these spaces.

Fences on the perimeter of the property may be expensive at the beginning but they are lower maintenance and use less water than a living fence on the perimeter. In the fact sheet I purposely stay away from recommending plant materials. There are plenty of places that can recommend plants for your area including your local garden club, nursery and extension office. The extension office in Pahrump has a great little garden area that demonstrates some plants for the area. They have lists as well.

Basic recommendations for trees for the desert are to keep them in scale with the house and property, and put them where they will do the most good and you can appreciate them. Every plant you put in the ground should have a good reason for being there. This is the desert and water is precious. I hope this helps a little. this is a big topic to cover.