Q. My trees are growing quite well and I was wondering what to do next to my magnolia, persimmon and crepe myrtle.   A. Thank you for the great pictures and breaking them into two emails. That helped quite a bit. Here are some comments on what I saw. First general comments. The plants are actually doing quite well, maybe even a bit too well. There is plenty of new growth which is what you want but because they are so “happy” they are growing very quickly and thus you are getting big spaces between leaves and buds. This results in an “open” appearance. Many of your plants, now that they are getting lots of nutrients, water and in a great growing condition are now growing as fast as they can. This will result in larger plants that will start to flower or fruit further and further from the ground as they get closer to their mature size. Plants do this naturally because in nature they are always competing for sunlight and other resources that keep them alive. How do slow them down? We focus on two things: reduce those “goodies” they are getting that encourage a lot of growth (water, fertilizer) and (this next part is harder to realize a bit) get the plant to reduce its own growth in each of its growing branches by increasing the total number of branches it has to support. This then causes the “goodies” that encourages growth to be divided up among many more growing points and slows it down. It’s like having an income of $50,000 a year and having to support three children or 20 children; your resources are divided up many more times  so each “child” gets less. Generally speaking, reduce “goodies” by reducing your watering frequency (how many times you water per week if possible but not by too much) and cut your fertilizer application in half (but not to the point where it is starving or gets leaf scorch) and (increase the number of growing points or “children”) prune. The type of pruning you will mostly do this winter will be what I call “heading cuts” rather “thinning cuts”. Heading cuts increase the total number of shoots in a tree while thinning cuts typically do not. If you want to see the difference, please visit my Youtube video on this subject http://www.youtube.com/watch?v=yKDSzCfvqe0 Now your individual trees, you must decide what you want for the ultimate height on these trees. If you want them to be large (such as flowering trees for beauty, shade or screening) then let them go and don’t do much pruning.  Crape myrtle showing some impressive growth If you want trees to be smaller and more compact (fruiting and harvest for instance) then you will cut them back pretty hard and take away from them their luxurious growth. You will prune these trees twice each year; once in the winter and again (taking away new fast luxurious growth) in April (summer pruning). Crape myrtle. I would assume you want a larger tree, perhaps with multiple trunks (3 to 5) coming from the ground. Don’t reduce the height. Let it go. Pruning will focus on removing dead, twiggy growth (it has lots of these due to flowering) and use thinning cuts to eliminate branches growing too close together, one branch growing on top of another, branches crossing each other, etc.). You can reduce the height by making thinning cuts and removing the tallest limbs and branches back to a “crotch”. I would not do much of this until it gets closer to the height you want it to get. You will fertilize in January with an all-purpose soil applied fertilizer such as 16-16-16 or even a rose fertilizer. You will see benefits from adding iron chelate to the soil in January and foliar applied fertilizers such as Miracle Gro about two or three weeks after the leaves emerge in the spring.  Magnolia open growth with sparse leaves Magnolia. This is another tree you could elect to let it grow. Having a multiple trunked tree will help to keep it smaller. You realize that this tree is not a terribly good choice for our climate so you will spend more effort and money on this tree than many others. It will need the mulch which you are doing. This will give it some soil improvement near the soil surface as it decomposes. It will require a fertilizer application in January to push new, healthy growth. It will also benefit from an iron chelate. It will not most likely need a foliar fertilizer but it will not hurt it if you chose to apply it in February or March. Your choice but it might do better if it is kept smaller than the mature height it will try to reach. Perhaps if you can keep it in the 25 to 30 ft. range it will be easier to keep healthy. Perhaps saucer or star magnolia might work better in the future. Not as pretty but still pretty. There is a southern magnolia called Little Gem that is smaller.    Persimmon growing perhaps a bit too erect and fast for its own good Persimmon. Cut this tree back hard if you want your fruit closer to the ground. Your tree is too lanky. Cut back into older wood about half way in where it is too long in late January or early February. Don’t be afraid to do this. It will handle the hard cuts. Fruit is produced on current season wood so it will flower and fruit from new growth. I hope this helps.

Q. I read your article this morning in the RJ and found there to be a significant difference in the watering recommendation  you gave versus that from Springs Preserve. Currently, we have set our drip system to three days a week for one hour each day. We’re using one and two gallon emitters on shrubs and multiple four gallon emitters on palms and trees. We have read our water meter and my wife is aghast. For the one hour we are using approximately 975 gallons without using any other water in the house. We have no grass. If we cut back to two days a week, what should we look for in terms of adverse effects? A. Sorry, I am not aware of what they recommend so I don’t follow the Springs Preserve recommendations. It is difficult to give one recommendation for everyone who lives in the Las Vegas Valley because there are so many different soils, microclimates and irrigation systems. I base my recommendations on a few things that I will cover here as a result of your question. And yours is a good one. One major piece of research I follow for the area is the plant water demand (called PET; Potential Evapo-Transpiration) that we developed in the Las Vegas valley about ten years ago. Water District. I attached the PET table for all 12 months for you to see. PET table for the Las Vegas Valley. This table tells you how much water (in a range of low to high and an average) tall fescue turfgrass will use each month. So in one year tall fescue will use anywhere from about 84 to 96 inches of water with an average around 90 inches. It also gives you monthly average water use in the same table, again in inches. I know, I know…..but my  controller is in MINUTES!   This is the same PET information but in graphical form. Notice how PET, or plant water use, changes through the calendar years. Water use in June and July are about 8 times more than in January and December.   When we irrigate there are three questions we have to answer to set a controller; 1. How many minutes should I set the controller (volume of water applied)? 2. Which day or how many days of the week should it come on (frequency of application)? 3. What time of day should I start watering? These questions don’t relate at all to what the plant needs and how it should be watered. Here is where the confusion lies. The questions are only directed at the setting an irrigation controller. By answering these questions we hope to try and match the plant water needs. We hope we enter enough minutes and water frequently enough that the plants get enough water.   A major problem with irrigating plants in any landscape with an irrigation system of pipes and valves is that the plant receiving the LEAST amount of water drives the setting of the irrigation controller. If we see a plant not getting enough water (and it might be only one plant in the entire irrigation circuit) we rightfully increase the amount of water it gets. Unfortunately, ALL the plants on the same irrigation circuit are increased as well…whether they need it or not. If one plant is not getting enough water, it is possible then that we might over irrigate everything else just to give one underwatered plant enough water. This is why it is critical that the number and placement of emitters for plants on the same irrigation circuit be determined all at the same time, not independently of each other. I will explain how to do that in another blog entry.   I will make a separate posting of how to choose drip emmitters and how many to use for each plant. If I forget PLEASE remind me to post it! A plant should be watered at each irrigation so that the applied water wets the soil under the canopy of the plant to a depth just past the majority of its root system. We are filling a water reservoir in the soil for the plant to draw upon, like a gas tank for a car. The water should come on again when about half of the water in the soil is gone (gas tank is half empty). We then fill this tank again to the brim and start over again.  Bigger plants typically have deeper roots and a bigger size. This means that “big plants need more water than little plants”. I borrowed this picture from an Arizona publication on scheduling irrigations but I don’t remember the title. A very nice publication.   With a normal gas tank for a car we might fill it when it is below 1/4 full. We can’t do that with plants. At 1/4 tank there is not enough water in the soil to keep the plant from wilting or dying… with the exception of true desert plants like cacti. With true desert plants you can go longer between irrigations because many are drought tolerant (they can survive in drier soils).   Add emitters as the plant gets larger. The gas tank is made larger in diameter (not deeper) as the plant gets larger. The way we make the gas tank larger (make it wider in diameter but the same depth) is by adding emitters under the canopy. More later.   The amount of water we apply to the plant is basically the same each time we water, all year long. This is why I tell people to keep the number of minutes on the irrigation controller the same all year long. If you drive your car less you don’t stop and fill it up the same day each week. As you drive less (less water is used by the plant) you fill your gas tank less often. You change the frequency of application (days each week). But you want to fill the tank or reservoir with the same amount of water each time as long

Q. I’ve just spotted Colorado potato beetle bugs and larvae on my tomatillo plants. I didn’t even know what they were until I did some research. I’ve never seen them out here before. I can’t find an organic pesticide that will kill them without hurting the bees and other beneficial insects. Do you have any advice for me? A. Make sure it is actually the Colorado potato beetle and not a look-alike insect called the Ten-Lined June Beetle. I have not seen the Colorado potato beetle in the Las Vegas area yet but it is possible. Until recently, Nevada was one of four US states that didn’t have this pest. Ten-Lined June Beetle             But I have seen the Ten Lined June beetle here and they look very similar to the Colorado potato beetle. I posted a picture of this critter on my blog. The safest way is to pick them off as you see them. In small garden plots this works well. You can also use a cordless vacuum cleaner and suck them up that way.               As far as sprays go an organic/biological pesticide called Spinosad, which is available in many nurseries now, will give some control. Colorado potato beetle adult (striped) and larvae without stripes on potato leaves in Kosovo.             Another organic/biological control chemical is Bacillus thuringiensis (Bt) var. San Diego (also called variety tenebrionis) gives some control if they are not resistant. This particular type of Bt controls beetles. But this organic spray is hard to find locally. You will probably find it only online.               There are Bt sprays in the nurseries but this is the wrong Bt spray for Colorado Potato Beetle. The one in the nurseries is Bt var. kurstaki (Btk). This Bt is used to control larvae or caterpillars that form moths and butterflies like the tomato fruit worm, tomato hornworm and grape leaf skeletonizer.

Q. I check all my plants weekly for possible problems. I noticed what appears to be some kind of white fuzzy things on my pear tree leaves and sent you some pictures. I didn’t want to mess with them in case they were from beneficial insects. I’ve searched on line but can’t seem to find anything. Have you ever seen them before? A. Yes, I have seen these white fuzzy, cottony things on all sorts of plants including herbs, citrus and vegetables. These are not good guys but they are also not terribly bad either. You can wipe them off or spray with soap and water.             I have posted pictures of this before on my blog but I will repost it again. These are probably the egg masses of the sharpshooter insect or a close relative. Be sure they are not mealybugs. If you don’t know what mealybugs are, ask and I will post some pictures. Truly one of the worst pests worldwide, particularly inside or in greenhouses but outside as well in wet climates.

 Q. I hope you can view the pictures that are attached. As you can see, one of my shoestring acacia is growing out on an angle and my fear is it will get to heavy and topple. Is there any way to save this tree by putting a support under the trunk or topping it by cutting it back? It was planted 7 years ago with two others and this is the only one that is doing this. It is about twenty feet high or so. A. Thanks for the pictures. Actually your tree looks nice in your setting. There are two things I am noticing from your pictures. First to answer your question, make sure the tree is getting water at distances equal to at least half the canopy area under the tree. You can do this by adding emitters or a water source in scattered areas under the canopy. If the only water sources are close to the trunk, the roots may stay too close to the trunk and begin falling over when it gets top heavy. By putting water further from the trunk it encourages a larger area of support for the tree and its growing canopy. These emitters under the canopy can be used to support other plants as well so that it is not just watering the soil for weeds to grow.  b Plant roots in container are circling. Bad, bad, bad. Borrowed from http://hort.ifas.ufl.edu/woody/container11.shtml Lawns around trees also help to support tree root growth that keeps trees from toppling over. Roots do not grow “in search of water” but will grow only where there is water in the desert. Rainfall does not count in a true desert like ours in the Mojave. If the tree or shrub was purchased in a container and the roots began circling in the container (the plant was overgrown in the container), they may continue to circle once planted and never create a strong foothold in our desert soil. The roots circle and circle and never spread out like they should. When the top gets big, these trees with circling roots tend to lean or blow over in a strong wind. They can become a liability as they get older. Unfortunately these plants can never be rescued and must be removed to prevent loss of property or cause safety concerns. Never buy plants in containers where the roots have grown in circles inside. They can never be established as healthy trees that are safe for public or private use. What to do? Determine if the plant is a liability or not. If it is, remove it. To determine if it should be removed, put enough weight on the trunk to see if you can get the trunk to move enough to get it to move back and forth. While moving it back and forth, look at the soil beneath it and see if the soil is moving or if the trunk is securely anchored into the soil. If the soil moves around the tree, you will have to remove it. It is a liability. If not, you have time to try to re-establish the roots farther from the trunk and give it more stability. This tree is too close to that wall and will probably damage the wall in future years.

Q. Firstly, I enjoy reading your column and have learned many gardening tips with great results. Since moving into our home three years ago, the Photinia or Hawthorne patio tree has a recurring problem with discolored leaves, usually in the spring and fall. It has been treated with Bayer Disease Control, Dormant Oil and Ironite as recommended by others, along with the normal seasonal fertilization.  There are three, 4 gph emitters. Hopefully, from the photos, you will be able to shed some light on the problem. A. I am sorry this is such a late posting back to you. What you have here basically is a nutrient deficiency problem. If these problems get to advanced they can be difficult to fix. When they’re caught early, it is relatively easy. Much of this problem has to do with the soil and the use of rock mulches around certain plants that are not very tolerant of the soil conditions that develop under rock mulch. What basically happens is that the good stuff in the soil I like to refer to as organic material has essentially disappeared. When plants are grown in rock mulches there is nothing decomposing and giving back to the soil and the soil becomes what we call “mineralized” or void of organic material. Organic material in the soil is very important to some plants. Photinia is one of them. When these plants are first put into the ground the soil is modified usually with some sort of planting mix. This planting mix is usually organic in nature. This organic material modifies the soil as it is decomposing and provides many benefits to the plants that help to improve its general health. As this organic material decomposes and is lost over a period of 3 to 5 years, these benefits disappear and the plant health begins to diminish. The leaf yellowing with green veins indicates a micro nutrient problem, like iron. in our alkaline soils and alkaline water. This is why would some plants organic mulches that slowly decompose can be very beneficial. Whereas rock mulches which do not add anything organic back to the soil tends to be harmful to these plants. True desert plants are usually much tolerant of very low organic matter content in the soil. While other plants that originate from climates where the soils organic material tend to do poorly growing in rock mulches. What to do? Obviously if we can add organic material like compost back to the soil it will help. Usually, however, by the time we notice it the condition is very advanced and recovery can be slow or nonexistent. The best thing to do is to get these plants growing back under organic mulches. Organic mulches do not include bark mulches. These are almost as bad as rock mulch. Wood mulches decompose and add life back to the soil again. You can pick up this type of wood mulch free from our Orchard in North Las Vegas and a Tuesday or Saturday morning. This is a case where you have to drive in and load it yourself into containers, bags or even a pickup truck. There is no charge for this organic mulch. This mulch is made from chipping trees that are cut down in Las Vegas neighborhoods. Instead of taking it to the dump and burying it, we have provided a location we can come in and pick it up for nothing. For more information on the mulch at the North Las Vegas orchard and how to get there, call 702-257-5555.   You can also try spraying the foliage with a liquid fertilizer such as miracle Gro and iron sprays. Make sure you use a wetting agent mixed in the liquid fertilizer so that it improves its chances of entering the leaves. The wetting agent could be a teaspoon of Ivory liquid in a gallon of water. Add the Ivory liquid to the water, not vice versa or you’ll get a bunch of bubbles. This will take multiple applications of the iron chelate but only a single application of the fertilizer. You can also apply the iron chelate EDDHA to the soil around the plant and water it in. The only nursery that is caring it to my knowledge is plant world on Charleston. They have this iron chelate labeled with my name on it because I recommended so often. I do not get a kickback or anything else from recommending it. It works for reasons that would take too long to explain here. So in a nutshell, surround your plants with organic mulches that will decompose. Spray the plants with a liquid fertilizer combined with a wetting agent now. Also spray the plant with iron multiple times about a week apart and include the Ivory liquid. Apply the EDDHA chelate to the soil now. The last thing to do is cross your fingers and hope for the best. I hope this helps.

Q. I have some Early Girl tomatoes that I planted in March from plantlets that I bought. I talked to the Early Girls about a month later and told them that if they did not flower in the following week, I would feed them to the worms in my compost pile. Well they seemed to have listened, because they made lots of flowers but the flowers didn’t set fruit. What did I do wrong? A. Tomatoes are pollinated by insects, primarily bees. However, if temperatures are in the 90’s and above they have trouble setting fruit. They just don’t like those high temperatures for pollination. They set better when temperatures are in the high 60’s and 70’s up to about 85F. Other reasons for flower drop and no fruit set might be uneven watering so it is a good idea to mulch the plants. Straw is a good choice. I think a bale of straw no goes for about $8 locally. Low night temperatures below 55F can cause flower drop as well.   Also over fertilizing with nitrogen fertilizer may cause no flower development until the nitrogen is depleted a bit from the soil.   If temperatures are good, the bee does not actually have to visit the flower. Vibrations from bee activity are enough to set the fruit. If tomatoes are grown in greenhouses for instance and there are no insects in the house, the movement of the plants from vibrations caused by an electric toothbrush is often times enough to get them to set. So make sure you have pollinator activity when temperatures are appropriate for fruit set. Otherwise, gently shake them while you are talking to them. Maybe a slight physical threat might work. Another thing you can do is buy some tomato fruit setting chemicals. These are synthetic copies of natural plant growth regulators called gibberellins. It is usually applied when temperatures are cool, not hot like they are now. They are sold in nurseries or garden centers with names like tomato fruit set or the like. Follow the label directions.