Shoestring Acacia Losing Lots of Leaves

Freeze damage to shoestring acacia

Q. I had three shoestring acacia trees planted 5 years ago and right now they are losing a tremendous amount of leaves. They are on high flow emitters that are adjustable and putting out a large amount of water. They get watered every other day for 15 minutes. The trees are approximately 20 feet tall.

            Is there any reason why they would lose so many leaves?  My understanding with these trees is they produce very little litter but that is not the case. I would appreciate any help you could give me on this. Also there are 4 emitters for each tree about eight to ten feet from the trunk.

A. Shoestring Acacias (Acacia stenophylla) has a long record of success in desert regions of the west.  This good history of success is often the result its adaptability and letting the soil dry between waterings. 

Flowers of shoestring acacia

            Your comment that the 'leaves' are falling (Oddity fact: The long thin 'leaves' are in fact phyllodes and not true leaves but do the photosynthesis) leads me to think the very frequent watering has set up conditions not conducive for a maturing tree.

            After 5 years in the ground I would think your watering cycle could be as much an issue as anything.  Unless you live on some of the very sandy, stable dune soils of Palm Springs or in southern California/southwestern Arizona (Yuma mesa area) trees in the ground for 5 years would be better watered much less frequently with a larger volume at each watering.  This would also include having the source of the water being moved out away from the trunk targeting the water out closer to the drip line of the tree. 

            Whether there might be a disease involved and complicating the situation is nearly secondary.  The watering regime you described could easily have set up the conditions for the fungus to get started and any treatment would include a change in watering schedule to allow drying between waterings.

            Please feel free to respond if you have any questions or other things that might have 'hit' the tree. Things like: root damage from digging, severe wind that may have damaged the trunk, certain herbicide (weed killer) usage, pool back flushing, inadvertent chemicals spilled in the area, compaction from parking vehicles in the tree's shade, etc. 

            I would be interested if you live in a marginal cold area.  This tree begins to suffer if the temperatures drop to the high 'teens.

Terry Mikel

Leaves of Shrubs Dry, Burnt and Falling Off Could Be Several Reasons

Leaf scorch on Cherry Laurel

Q. I now water once a week but my shrubs are looking like they might in the hottest part of the summer. Leaves look dry, burnt and falling off. My average shrub is about 3'x3' and receives 3-4 gallons per week week based on my emitters and time on. Did I cut back too much ? What should I do to try to revive them ?

A. Your watering sounds very appropriate and probably what I would have scheduled as well. You have to make sure, however, that the water which is scheduled to be delivered to your plants is actually getting there. Make sure you check for plugged emitters when the system is on. You should have a filter on your drip system even if you are on city water.

Leaf scorch on mockorange due to chlorosis and inadequate
plant nutrition

             It could be several possibilities. I have to walk through them with you because I don't know much about their previous history. For me, it looks like possibly watering, possibly collar rot at the base of the trunk where the rock mulch sits against the stem, it could be very low temperature damage as possibilities. If there were some very low temperatures just prior to that than this could be just that. If there were no low temperatures than most likely it is not. Then we have to look at watering issues including the rock against the trunk.

First determine whether the plant is dead or not. Bend some branches and see if they snap. If they are still supple and just have damaged leaves then it is a temporary setback and they will regrow and set new leaves in the spring. If they snap when you bend them, it may be dead. You will have to pull it anyway so start bending the branches and see how much of the plant is dead. If the amount is sizable, remove it. When you remove it look at the trunk where the rock mulch was resting against it.

Planting so shallow that the container mix from the nursery
is exposed to the open air and wicks water from the
rootball

Use a knife or your thumbnail and scrape the bark away from the trunk starting about an inch above where the rock mulch sat and down along the stem to the roots. Look to see if there appears to be a dark area or rotten area in the trunk or bark around the rock mulch line. If there is, then it is collar rot. Make sure on any new shrubs that rock mulch does not lay against the trunk or, in some cases, the plant was not planted too deeply. It should have been planted the same depth as it was growing in the nursery container.

Nurseries don't have many plants this time of year because they are trying to reduce their inventories. You can look for a replacement plant but chances are you may not find one that you like until next spring when it gets warm.

I hope this helps.

Flies A Big Problem in Parts of the Las Vegas Valley

Q. My husband and I spend four months away from the Valley during the summer. When we returned in late September we could not believe the number of flies in our yard.....and because we are used to leaving our doors open....in our house. We have always bragged to those less fortunate than we are and live elsewhere in the country, mainly in the East, how we have virtually no flying insects in Las Vegas. I've had to eat my words this fall....along with some flies. I have not been able to even sit outside and read without being bombarded in the face with these nasty insects. We live in Sun City Anthem....the far southern end of the valley. Is there something blooming/growing in my yard that flies really like? Has anyone else noticed this proliferation?

A. Yours is the first report I have seen about an increase in flies this year. I do not know the products that are used for flight control, which is not an area of expertise for me. I would suggest however that somewhere, someone may be using a source of compost or manure products that are attracting flies.

The best advice I can give in the safest is to find out what is attracting them and where and address the problem there. If you do not do it this way and simply spray to control flies or use some sort of sticky trap you will not solve the problem but just work on the symptoms of a problem. I hope this helps.

PS. Since this was printed in the newspaper several people wrote to me and said they had the same problem. I lived in the valley at the time and I didn't really notice it. Anyone else have any suggestions?

White Fluffy Stuff on Cactus Can Be Removed Easily

Cochineal scale on Opuntia or beavertail cactus

Q. My wife and I read your interesting article regarding white spots on cactus. Yes, we have them and didn't know what to do about it. Now we do. I zapped the beavertail with a solid water stream and within seconds the spots were gone and the beavertail looked as good as ever. Many thanks for the simple solution to an otherwise difficult problem.

Using a hose and sweep nozzle to wash off cochineal scale

A.This is cochineal scale. A very similar cousin to this one was used for making a beautiful red dye. Remember that this does not get rid of them permanently.

They will come back relatively soon and you will have to repeat spraying with your hose. If this becomes bothersome then you will have to rely on a pesticide such as Sevin after you hose them off.

Make sure you read the pesticide label before applying it.

Blue Point Juniper Unique to the Las Vegas Area and Probably Has Mites

Q. My 9-foot tall cone-shaped blue point juniper has a huge area that is turning brown. What can I do to restore the burnt-like brown to a normal green? I looked at the brown area closely and found whitish cobwebs with little white dots on the area.  What mites are inhibiting the juniper and what is the best way to get rid of them?

Click here to see a Blue Point Juniper

A. Junipers are notorious for two things and uprights possibly a third; spider mites which are frequently associated with webbing, root rot when they are planted in heavy soil or if they are watered too frequently or both and possibly borer damage. Damage from overwatering usually appears at first as single branch dieback.

            Blue Point Juniper is a small to medium sized upright very small tree or shrub that is cone shaped with a bluish green color. This is a very pretty plant in the right landscape. I have not seen very many of them growing here in our landscapes.

Webbing from spider mites

            Spider mite damage can cause browning but normally the surrounding foliage of the juniper appears to be dusty looking. Most of this dustiness appears, to me, to be dead mites. Spider mites are extremely small, about the size of the period at the end of this sentence.

            The webbing may not mean anything. Just because there is webbing does not mean it has a problem with spider mites. Spider mites can be of a type that creates webbing or it may be of a type which does not. Secondly, there are good mites and bad mites. The good mites help to control the bad mites so spraying a chemical aimed at controlling mites may just backfire.

            The best way to determine if spider mites are an issue is the paper test. Take a white sheet of paper and a branch of the juniper and slap the branch or foliage against the white paper. Hold the white paper still and look at the dust or debris on the paper. If spider mites are present you will see a number of tiny dots the size of a period moving on the paper.

            Usually spider mite problems begin developing during the heat of the summer, not when it is cool. Soap and water sprays once a month during the summer is a common way to try and keep spider mites from becoming a problem. If the problem is severe than that may require a miticide or insecticide for controlling mites.

Scanning electromicrograph of spider mite the size of a
pencil dot.

            Since you have had this juniper for quite a while it is probably not root rot due to overwatering unless you have recently changed the irrigation pattern or if there has been a release of water near the plant in the past few months. This might be from a leaky irrigation valve or broken pipe.

            Borers in major limbs or branches are a problem on some upright junipers such as the Hollywood twisted juniper. It might be on this plant as well. Boring insects that tunnel into these branches cause these limbs to die while the surrounding area stays green. Pull the canopy of this juniper apart and look at the limbs inside of it to see if there is sap coming from a limb or limbs. The damaged limb is pruned out just below the sappy area.

            Once a branch is damaged and it has turned brown it is difficult to get it to come back to green again. If the damage is not severe it might come back over time if the problem that caused the browning is corrected. If the damage is severe it may be permanent like the toothless gap of a smile and never repair itself.

            The nurseries to carry a green paint that can be used to help the plant cosmetically. This is a problem with plants that grow beautiful, perfect cones of canopy.

Response

Thank your very much for your detailed response.  My two blue point junipers are doing quite well now after I sprayed them with insecticide.  I live in Sun City Anthem and you are right--nobody else has these trees.  Mine are now six years old, eight feet tall and trimmed to a conical shape.

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.

Know When to Harvest and Roast Your Own Almonds

Q. We have a young almond tree that has a great cop of nuts on it.  Questions: 1. How do we know when to harvest?  2.  Is there any special prep needed before eating the nuts?

Almonds split and ready for harvest

A. Harvest when the outside covering has split open. You can leave them on the tree longer as long as it does not rain. If you have ground squirrels, harvest immediately or they will get them. You can open the husks any time or store this way for a long time if they remain dry. Eat them fresh (my preference) or you can roast them. Bake at 350° or so for 10-12 minutes or until you smell a nutty aroma. Sprinkle with salt or your favorite seasoning if you want.

Almond dried on the tree and ready to harvest and sell
in the husk

            I want to add something here. Years ago when we began harvesting almonds at the Orchard, the volunteers spent very many hours splitting the outside husk open, taking out the nut and getting the nuts ready for the Farmers Market. I had so many complaints from the volunteers about this work that no one would do this anymore. So I told them to take the nuts, husk and all, to the market and sell it that way.

            Well what a shock! The people at the Farmers Market LOVED them this way! They would take them home and show their kids where almonds came from and what a surprise the kids had opening them and eating them fresh from inside the husk. And we made more money this way than if we had husked and taken them out of the shell. No more complaints and plus there was much less labor involved.

            If you do have almonds, a serious pest you can get is peach twig borer. They will get in the husk AND in some cases find their way to the nut after the husk has split. So get them off of the tree soon after they split sometime in August.

Is Iris Borer in Southern Nevada?

Hole in iris leaf

Q. While cleaning my iris beds this morning, I found quite a surprise.  I hope you can help identify my problem before I have more damage. I put 100% white vinegar in this hole and it foamed up immediately. I hope I didn't kill my Iris - the hole is right in the middle of the plant.  Further checking revealed that I have these holes in several of my iris beds spread over 1/2 acre.

            I also found what looks like a "perfect" 1/4" round, 1 1/2" excretion, it is almost black.

I've checked on the internet and there is nothing that describes a 1" hole with mounded dirt; the round holes are perfect in the ground and on the leaf.

            Some suggest slugs - I have no type of residue and I think they would eat as they go NOT make a round circle in the middle of a leaf. Then cutter bees were mentioned but their holes don't seem to be as big as these. I will soon be leaving town and I would like to get a handle on this problem before I go. Thanks for any help you may give.

A. I hesitated to answer for a bit because I was not quite sure what is going on. My first reaction was iris borer except that this iris pest is not usually a problem here but rather in the Midwest.

Hole in the ground near the iris

            But it fits the description. They will leave roundish holes in the leaves and they also pupate in the ground so when the moth emerges they leave this fairly large, smooth hole in the ground near the iris.

            But you mention no other symptoms of iris borer which also makes me doubt it. Other symptoms would include, in the early stages, the tips of the foliage turning yellow and then brown. As the problem gets worse the base of the stalk may become yellowish-brown and mushy with a bad odor if the attack is severe. This is when rot of the rhizome has started.

            If you are digging irises to divide or move them this fall, you may notice holes in rhizomes as well. If you got any of these rhizomes from the Midwest then it is possible they may have been transported here.

            I agree that it is also possible that the hole in the leaf could be from slugs although, as you pointed out, you are not using any surface mulch which they like. The hole in the ground could be from an insect like the cicada killer, a large wasp that is yellow with black stripes, not very threatening to humans but can deliver a severe sting if provoked. Normally cicada killers will not bother you but they do have a very large hole in the ground that fits this description and the picture you sent.

            I will post both of your pictures on my blog. But first I would check to make sure it is not iris borer when you dig up some iris this fall for inspection. If you see some iris with foliage that is yellowing or dying back I would dig and look here first.

            Look for holes in the rhizome or even possibly mushy rhizomes. I would discard these and hopefully you will see no other problems. If you do not conclude it is iris borer then I would assume it is a cicada killer and not be concerned about it. Watch for slugs and put out some slug bait or stale beer for them.

Palm Tree Fronds Dying at the Bottom

Q. We have a couple of fan palms whose fronds are continually dying off from the lower level.  Is this normal or are they lacking in something i.e., water, nutrients, etc.

Readers palm tree

A. I looked at the picture of your fan palm. In this case, yes, this is natural. The fronds grow from a central bud located at the top end of the trunk. All of the new growth for a palm tree comes from this bud. If the bud dies, the trunk is dead. If the palm has one trunk then the tree is dead.

            As these new fronds emerge from the bud, the older fronds (the ones at the bottom) begin to die. Normally you would expect the fronds at the bottom to die in this manner. First they will begin to yellow and then eventually they die. As these lower fronds yellow, it is then an appropriate time to remove them.

Palm trunk skinned

            I like to cut the fronds as close to the trunk as I can leaving very little stub coming from the trunk. Some people remove the stub even closer to the trunk, at its point of attachment to the trunk, by cutting with a sharp knife (box cutter or linoleum knife) at the point where the frond attaches to the trunk. This is called "skinning" which results in a very smooth trunk which some people like. It also lessens the chances of having bark scorpions living and looking for food on the trunk.

            You can remove these older dying fronds any time of the year. If you elect to remove green fronds then remove green fronds that are only in the total shade of its canopy. You can also do this any time of year as well but best done during the summer or late spring months.

Tropical Bird of Paradise Tough to Pull Off in the Desert

Q. How do I plant and care for the “Tropical Bird of Paradise" in the desert?

Growing Tropical Bird of Paradise in the Desert

A. These are those very pretty flowering plants with banana-like leaves you see in San Diego or other places where it does not freeze. Tropical bird of paradise, as its name indicates and you are probably aware, will not handle any freezing temperatures. So this is a plant which has to be protected during the wintertime from extreme cold and winter winds.

            The plant itself can handle temperatures to the mid twenty’s for a short time but the flowers cannot. If flowers or flower buds are present it cannot be subjected to any freezing temperatures at all. This means you can grow it in containers or in the ground provided you take the time and cover it or move it into a protected area to keep it from freezing.

          The second very important item is modification of the soil. Our desert soils will be brutal to tropical bird of paradise but not impossible provided they are amended appropriately. This means you will need to heavily amend any local soil with about 50 to 75% manure-based compost. After planting, the soil should be covered with 3 to 4 inches of organic mulch such as wood chips but not bark mulch.

          Fertilize with manure-based or slow release fertilizers every three months during the growing season. Make sure they are planted with an eastern exposure in filtered shade and not subjected to intense afternoon sunlight.

Sharp Thorns on Grapefruit Might Very Well BE Grapefruit

Q. I read your answer few weeks ago to questions concerning sharp thorns on branches growing from the base of an orange tree. I have a Rio Red Grapefruit semi dwarf tree which is about 3 feet tall. The main trunk is topped buy 3 branches spreading out in different directions. One of the branches has several sharp thorns on it as well as soft thorns to very soft thorns on it. The other branches do not have sharp thorns. My questions are 1) should this branch be removed or is this a normal occurrence and 2) will the sharp thorns soften in time? 

A. Robert passed this to me and before an answer can be given we need to make sure of something . . . The branches with thorns, are you 100% certain they are not a shoot arising from the rootstock? . . Follow it back to where its connected to the trunk and if it arises from down low near or below the soil line then cut it off as it is a rootstock sucker. . . 

Otherwise, many Citrus shoots have thorns that start out soft, become rigid and then, over time most get absorbed back into the plant with maturity. . . . The thorns invariably are on vigorous vegetative shoots that need a period of time before they convert to flowering and fruit producing tissue . . . If the branch isn't hanging near where people walk by and could get stabbed then let the branches go . . Over time they will change from the vigorous to the more sedate fruit producing wood and the thorns will be but a memory . . 

But first make sure the branch(es) with the thorns aren't from the rootstock . . . You do understand the cost for this advice is for you to share those beautiful Rio Reds with friends and neighbors. . . 

Terry Mikel

Ornamental Pear a Good Choice But Needs Special Soil Preparation at Planting

Q. We recently planted a fruitless Bradford Pear tree in the place of a tree that was dead. It is in good soil which I mixed with planting dirt from Star Nursery, where we purchased the tree. It was in a 15 gallon pot and is about 10 feet tall in the ground, so I would think it is possibly two to three years old. I realise this is not the best time of year to put a tree in the  ground, but hope that it's maturity will give it a good start. We had a number of these trees in our yard from new when we lived in Texas and they did very well in the heat there. So I wonder if you have any advice or tips for us now we have one here in Nevada. We did do the 'call before you dig'. Any advice etc will be really appreciated

A. Ornamental pear varieties like Bradford, Chanticleer and others perform reasonably well in our desert keeping in mind they are not desert plants. I have watched them growing for many years along Maryland Parkway in front of the Boulevard Mall and across the street from it.

            They have beautiful blooms in the spring and a nice round, dense canopy provided they are planted and maintained properly. They probably should not go into the hottest part of the landscape with a lot of reflected heat.

            With this in mind they will never perform well for any length of time in a rock mulch landscape. They may do okay growing in rock mulch for a few years but after about five years the leaves will begin to yellow and scorch, the canopy will thin, and branches will die back.

            When this happens, it will be open to borer attacks, the same kind that attack other fruit trees. These trees should be planted in an organic mulch such as wood chips which decompose and add valuable organic material back to the soil.

        Ornamental pears should be planted with lots of organic material in the planting hole, they need to be staked solidly for the first growing season. After the first growing season they should be firmly established in the soil.

            Fertilize them once a year just like you would any other fruit tree. Use a well balanced fertilizer with the three numbers the same such as 8-8-8, 10-10-10, etc or fertilizers sprayed on the foliage 3 to 4 times after the leaves emerge before it gets hot. They will benefit from periodic applications of iron because they will get yellowing from iron chlorosis.

            I like to divide our landscapes into three water use zones; high water use, moderate water use and low water use. These water use zones represent the total amount and frequency of water applied.

            These trees could easily go into the high or moderate water use zones but never the low water use zone. The watering frequency would be the same as other large trees and shrubs as you would apply water under the canopy so that at least half the area under the canopy is wetted to a depth of 18 inches.

Sharp and Soft Thorns on Rio Red Grapefruit a Problem?

Q. I read your answer few weeks ago to questions concerning sharp thorns on branches growing from the base of an orange tree. I have a Rio Red Grapefruit semi dwarf tree which is about 3 feet tall. The main trunk is topped buy 3 branches spreading out in different directions. One of the branches has several sharp thorns on it as well as soft thorns to very soft thorns on it. The other branches do not have sharp thorns. My questions are 1) should this branch be removed or is this a normal occurrence and 2) will the sharp thorns soften in time? 

A. Robert passed this to me and before an answer can be given we need to make sure of something . . . The branches with thorns, are you 100% certain they are not a shoot arising from the rootstock? . . Follow it back to where its connected to the trunk and if it arises from down low near or below the soil line then cut it off as it is a rootstock sucker. . . 

Otherwise, many Citrus shoots have thorns that start out soft, become rigid and then, over time most get absorbed back into the plant with maturity. . . . The thorns invariably are on vigorous vegetative shoots that need a period of time before they convert to flowering and fruit producing tissue . . . If the branch isn't hanging near where people walk by and could get stabbed then let the branches go . . Over time they will change from the vigorous to the more sedate fruit producing wood and the thorns will be but a memory . . 

But first make sure the branch(es) with the thorns aren't from the rootstock . . . You do understand the cost for this advice is for you to share those beautiful Rio Reds with friends and neighbors. . . 

Terry Mikel

Cactus Sale and BBQ June 21 at 6:30PM UNLV Center

Come on out to the Cactus sale and BBQ on June 21, 2012, at 6:30 PM at UNLV's Center for Urban Horticulture and Water Conservation. They have been growing cactus for the public and have two presentations ready for people who come:

How to Grow Melons
Scorpions

Burgers $1.25
Soft Drinks  $0.75