August 19 Webinar: Coronavirus Food Assistance Program Additions

USDA to Host CFAP Producer Webinar August 19 to Discuss Newly Eligible Specialty Crops, Nursery Crops, Cut Flowers and more

The U.S. Department of Agriculture (USDA) will host a webinar on August 19 at 3 p.m. ET to discuss recently added commodities eligible for the Coronavirus Food Assistance Program (CFAP). Join the USDA Farm Service Agency (FSA) for detailed examples on specialty crops, nursery crops, cut flowers, eligible aquaculture and more. USDA has extended the deadline and is accepting applications for CFAP through September 11.

Visit the Website and Register

Remove Mesquite While its Young and Replace it With Something Smarter

Q. A couple years ago our builder planted a multi-trunk Chilean Mesquite tree in our side yard which borders a street. The tree is planted 12 feet from the house but is only 5 feet from a block wall. I am concerned this tree will become huge and its root system may disrupt the wall since there are several irrigated shrubs on the other side. I am thinking of removing it while it’s still young and replacing it with a “tamer” tree.

A young mesquite tree in good landscape form and enough space to grow. It can get 50 feet tall with irrigation and fertilizer.

A. That’s a good call and very forward thinking on your part. This tree will grow quickly to about 50 feet with an equal spread. If you are going to replace a tree, this fall would be the right time to do it. Remember, planting smaller sized trees will overtake planting larger trees in one or two seasons of growth. No reason to buy larger trees unless you need immediate impact from them.

Texas or Mexican olive (Cordia boissieri) with irrigation. A smaller tree for smaller areas than mesquite.

            If your home is a single-story home, consider two small desert trees to replace a single big Chilean Mesquite. Plant them a distance apart equal to their mature height and about half their mature height from the home. If this tree area is on the south or west side of the home, make them winter deciduous for winter heat gain. All you want are trees large enough to shade the walls and windows during the summer.

Little leaf cordia (Cordia parvifolia) as a very small street tree in Las Vegas. Another landscape tree much smaller than mesquite and native. Use two of these small trees instead of one mesquite for shading exterior walls.

            Tree roots follow the water. Roots will grow wherever you apply water, or they find wet soil. Keep applied water 3 foot from the foundation of the home and the wall. It might not be a bad idea to install a root barrier between the trees and the home’s foundation and block wall. But watering lengthwise and parallel to the home will encourage the roots of the newly planted trees to grow in that direction as well. Tree roots do not have to grow in a circle under the tree.

Cicada Damage to Ash Trees May Be Confusing

Q.  Several years back my father and I planted two Raywood ash trees in each of our yards. Now both of trees have longitudinal gashes along the stems that kill many of the smaller branches. Last year I  found the same problem on one of my rose bushes. Per the recommendation of the nursery I sprayed a systemic containing imidacloprid and clothianidin on the trees.

My picture showing cicada damage to small stems on Acacia.

A.  This sounds like egg laying damage by the Apache cicada; those high-pitched insects you hear buzzing in about July. The insecticide you are spraying will not correct this problem so stop using it.

This female cicada is not laying eggs...yet..

            Apache cicadas make that buzzing noise so they can mate. Once they have mated, the female lays eggs in a slit she creates on the branches. If these slits cause enough damage, the twig dies. The eggs then hatch, and the insect drops to the ground where they burrow into the soil and feed on plant roots. Lots of different trees are favorites, your ash trees (sounds like the roses, too) being among them.

Cicada empty skin or exoskeleton left behind on anything they can find when they emerge from the ground.

            Spraying the tree with an insecticide, or drenching the soil with one, is not a good idea. I think your best bet is to give your trees as much chance to heal themselves, after the damage is done, as possible. Their best chance of healing from this type of damage is the presence of fertilizer in the soil and adequate water during the heat. Of course, scaring these insects off to other trees during mating time would help.

            Make sure these trees are fertilized in the spring and bump up the amount of water applied when you start hearing the buzzing noise. You might even try watering every other day during this period to help the tree recover from cicada egg laying damage.

One Stem of Pomegranate Not Green

Q. One of my pomegranate trees has very pale leaves on one of its branches and dark healthy green leaves on the others.  I put nitrogen fertilizer on both sides of the tree plus we did put a balanced fertilizer on it and some compost.

Pomegranate with one stem off color. What to do? Read on.

A. When one branch of a plant is dramatically different in color while the other branches are healthy, it means that whatever is causing this problem is at the bottom of that sick part. Since borers are not common in pomegranate the cause is most likely manmade or a disease problem.

            Look at the main stem just below the yellow leaves. The leaves below this point should be healthy while the leaves above it should be sickly. If the entire stem is sick, then look at the stem just above and below where it enters the ground.

            If the entire stem is sick but alive then I am guessing it is damage below this area from tools, machinery, or disease. If the stem is totally dead then it involves a lot more guesswork. Mower damage, if planted in a lawn, can cause this type of damage. This type of damage makes the plant worse during hot summer months when everything is more stressed. Line trimmer damage can cause the same type of damage as mowers. Diseases like “collar rot” that “choke” the stem, when the plant is kept moist all the time, can cause the same visual damage as mowers and line trimmers.

            What to do? If there is mulch surrounding the stems or anything that can act like a sponge and hold water, pull it back and away from the stems 6 to 12 inches and let this area dry out.

            Never water daily. Always give the soil a chance to “dry out” before watering again. The only areas of a landscape that need daily watering are lawns, vegetable gardens and flower beds.

            Whatever the cause, this yellowing stem probably should be removed. Sanitize your lopper, pruning shears or saw with alcohol and remove the stem at ground level. It is best to do it in the fall or winter, but you can remove it now on pomegranates with no problems.

Heatmaster Tomato: Heat tolerant for Desert Gardens

Q. I found a tomato variety that’s doing great in my garden called Heatmaster. I can tell it’s a determinate type because it’s loaded with tomatoes right now, pretty much all at the same time. I’ve read determinate types die after the tomatoes ripen. Is that true? Can I root it from a branch and plant it next month for a second crop even though it’s a determinate type?

A. Yes, Heatmaster is a determinate type regarding how the plant grows and produces tomatoes. But be careful. You can root this tomato from suckers but creating new plants from suckers is difficult to do in this climate. Try it and see how you do but it can be done.

            Determinateand indeterminate tomatoes have their pluses and minuses. (FYI...there are indeterminate Bush tomatoes.) You can usually tell if its determinate from where the fruit is produced. Determinate tomatoes produce their fruit at the ends of stems while indeterminate types typically produce along its stems. Most of what I heard about heat tolerant tomatoes like Heatmaster is regarding their taste.

            Determinate types of tomatoes usually do not die after they set fruit. Tomato plants are tropical perennials. Death is typically from disease or problems associated with high temperatures. A determinate type tomato is good to have in the garden, but indeterminate types work as well. Just handle them differently.

            So-called heat tolerant tomatoes like Heatmaster, Phoenix (also determinate) and others were bred for warm southern climates and not for the hot desert. They might set fruit at temperatures a few degrees warmer than normal but not when the air temperature gets into the 100s we sometimes see.

Collection of tomatoes grown in Las Vegas in 2005 including Sweet 100 Cherry tomato, Snow White cherry tomato, yellow pear, Ivory Egg heirloom and Black from Tula heirloom.

         If you have cool weather during fruit set then any tomato will set fruit including heirlooms like Mortgage Lifter and Brandywines. That’s why you may have good luck with hard-to-set tomatoes some years. Some of it is the “luck of the draw” as far as weather goes but a favorable garden environment that limits wind and wide temperature swings helps. Be careful about relying on one year of good production to make future buying decisions.

            Plant several types of tomatoes rather than focus on one variety. Cherry, grape and pear tomatoes are the easiest to grow and set fruit the easiest. Most of these are indeterminate types. Probably the next easiest are the plum type tomatoes like San Marzano and Roma. For some reason disease prone Early Girl (indeterminate), hybrid Celebrity (bushy but indeterminate) and even Burpee’s 70-year-old Big Boy (indeterminate) are good performers in our finicky desert climate.

            Make sure there aren’t other reasons for a lack of fruit set such as low humidity and a lack of pollinators. Plant herbs to attract pollinators like rosemary, basil, thyme, mint, and fennel. Put out water in flat trays and clean it often. Bees visit many of the flowering herbs and clean water they can haul back to their hives when tomatoes start flowering.

Black Streak on Mesquite Tree

Q. I have a 30-foot tall Chilean Mesquite tree that looks nice and healthy but has a 2-foot long dry black streak on its trunk. What is it and what’s the problem?

Black discoloration of mesquite trunk from my pictures

A. These dark streaks on the trunk are a common occurrence on mesquite, particularly if it had been pruned in the past. In common vernacular, the tree “bled” after it was pruned. If your tree otherwise looks healthy, then there is nothing to worry about.

Wetwood aka Slime Flux  

            Mesquite gets a minor bacterial disease problem called wetwood, a.k.a. “slime flux”, which causes a similar staining on large limbs and the trunk. But the black stain is constantly wet and “smelly”. Slime flux is a bacterial infection deep inside the tree which causes a wet “yeasty” oozing to flow from limbs that attracts flies. It’s spread from tree to tree by lots of things including “tree trimmers” that think they are arborists. It’s not a lethal disease problem for the tree, but it may cause owners some angst.

Slime flux bacterial disease on African sumac.

            I have a picture of a mesquite tree with a black streak on its trunk on my blog. I will repost it for you to look at and compare.

Frasers Photinia vs Red Tip Photinia

Q. What is the difference between “Red Tip Photinia” and “Fraser's Photinia”?

Red Tip or Frasers Photinia

A. My understanding is that they are the same plant, just different common names. The Latin name has both Photinia and Fraser (fraseri) in it. This explains why it is sometimes called Fraser’s Photinia. Because it’s new spring growth  is red, it is sometimes called Red Tip, or Red Tipped Photinia. I prefer the name “Red Tip Photinia” because it describes the plant better than calling it “Fraser’s Photinia” or just “Red Tip”.

            When in doubt about the plant go back to the Latin name to see if it’s the same plant. Plants can have several different common names but only one agreed upon Latin name.

            By the way, this plant is considered “mesic” (needs to be watered more often than “xeric” plants), grows better in amended soil and doesn’t like to grow in hot spots or surrounded by rock.

Creosote Bush and Spider Mites

Q. About a year ago you helped us diagnose a spider mite problem on our creosote bush. We took care of that as you directed. The results were encouraging and seemed to get the problem under control. However, we think the mites have come back with a vengeance and considering a severe pruning to revive it.

Creosotebush cut down probably with a grader in the front and unpruned creosote bushes in the back.

A.  Creosotebush can be cut back to a few inches above the ground and it will grow back after a few occasional waterings. Look at the creosotebushes mowed off near desert roads probably by a road grader from the DOT. Because they were cut down and got some extra water from the road when it rained, they came back like gangbusters; dense and green.

Predator/Prey

            What concerns me more is why the spider mites got out of control in the first place. Creosotebush has its share of spider mites naturally, but they are frequently controlled by predators such as other insects and mites. However, in your case, the balance between “good guys” and “bad guys” got out of hand with the “bad guys” winning.

            The problem with spraying a pesticide is killing off the “good guys”, then the “bad guys” get out of control because few or no predators are left. So, we usually avoid spraying pesticides unless we don’t have any choice.

Cutting Back Creosote

            I like your idea of cutting it back and letting it regrow. But I think you also must do something different or the spider mites will just be back again.

Weed Control

            Control weeds in the area. Spider mites like to feed on many kinds of plants including weeds, and these can play host to a growing population of “bad guys”. Secondly, be careful of watering too often. Creosote bush should never be on an automatic irrigation system because it just doesn’t like to be watered that often. Water it no often than four times a year with three of those irrigations during the hot months.

Cause of Leaf Drop in Chitalpa

Q. Is it common for the Chitalpa tree to partially defoliate in the summer? What would be the optimum amount of water for 15-foot Chitalpa tree growing in Kingman, Arizona?

Not the readers chitalpa but s picture I had.

A. Chitalpa, like some African sumac, is notorious for leaf drop in the middle of summer. According to several authorities from New Mexico and Arizona this is common with this tree.

Bacterial Disease

            According to the plant pathologist from New Mexico State University, this tree has a bacterial issue that causes some of its water tubes to get plugged. This causes the leaves on the tree to get scorched like it’s not getting enough water and in severe leaf scorching, the leaves drop.

            It’s similar, if not the same, disease we see on grapes called Pierce’s Disease. You can try giving it more water all under its canopy and see if that helps. If it’s a lack of water because it’s not getting any you will see the tree improve. Anyway, apply enough water to wet the soil under the canopy a depth of 2 feet.

Spread to Grapes

            From what I understand there is no cure for this disease and  ach plant has it because of how it’s propagated. Some scientists think this disease may be transmitted by a small insect similar to a leafhopper. So, get rid of any weeds growing nearby to the tree. It is possible this disease could be spread from your Chitalpa to nearby grapes. The symptoms are similar; leaf scorch and leaf drop but in grapes its eventual plant death.

Hibiscus in Pot Needs Renewal Pruning

Q. I have a hibiscus in a 20-inch clay pot with wrinkled flower buds, small leaves, and leggy stems. The hibiscus gets filtered light on my South facing patio and gets hand watered every other day.

This is a hibiscus growing in a 20 inch pot.  Some hard renewal pruning is needed and repotting the plant.

A. I looked at the picture of your potted hibiscus and I think it is getting large for its container. This is a 20-inch container and the size of the main stems are larger than thumb sized. That’s because you are pruning all the small stems from the outside and not pruning the larger stems toward the center. Your pruning style is also the reason it’s getting “leggy”.

            I think you have two options; you can either get a larger container or cut the hibiscus smaller. Let’s me explain how to do “renewal pruning” on it first. I think that’s your best option.

Renewal Pruning

            Renewal pruning, cutting deep inside the shrub and removing larger wood, results in a flush of sucker growth from the remaining “stubs” that eventually fills the open areas. This flush of sucker growth will be succulent and produce lots of leaves and flowers. You then select the best suckers to establish a new plant. Basically, you are “renewing” an older shrub by reinvigorating it.

            Prune the main stems as low as 4 to 6 inches from the soil. This sounds  dramatic but in hibiscus it results in a flush of new growth from below the cuts. Doing this causes it to sucker below the remaining stubs with new growth filling these open areas. In previous pruning  you were removing from the perimeter. Do renewal pruning as soon as weather cools off in the fall and new growth will cover the deep pruning cuts before it gets cold.

Repotting

            After you finished renewal pruning your hibiscus, gently ease it out of the container and remove the soil from around the roots. Keeping the roots moist, prune a couple of large roots and replace the soil in the container with fresh soil. Repeat this renewal pruning and repotting process about every three or four years to keep it young and vigorous.

Prevent Splitting Tomato Fruit

Q. All the YouTube videos say when tomatoes form and we get a rain, they tend to start splitting. We are on a drip system and have steady water all through the growing  season. Any help you can give would be appreciated.

Tomato fruit splitting

A. To prevent cracking or splitting of the largest fruit, the best thing to do is to turn on the drip system just before it starts to rain. I know this sounds counterintuitive but here is the scientific explanation. 

Science Behind It

Rainwater enters the fruit and causes it to split because of differences in salt concentrations inside the fruit, which include the sugars and starches, and the rainwater. Turning on the drip system when it begins raining puts water into the fruit, diluting the salt concentrations, and helps reduce cracking or splitting of the fruit.

            The second thing to do is harvest large fruit close to maturity before it rains and let it ripen inside the house. The fruits most affected by rain are the larger ones and usually red ones. These two things will reduce fruit splitting but not eliminate it unless you are just plain lucky. 

Application of Insecticides Depends on the Label

Q. Please advise where I can find this borer control product you recommended to me for soil drenching. The product I found has only 1.47% imidacloprid in it. Is this strong enough for soil drenching?

A. This question opens a “can of worms” I tried to avoid earlier by only recommending a single product. Initially when evaluating a product for borer control as a liquid soil drench, two questions should be asked: 1. Does this product contain imidacloprid in the ingredients? 2. Do the instructions explain how to apply it as a soil drench to the type of plant I am treating? The instructions will tell you how to use it correctly.

Homeowner vs Professional Concentrations

            There is frequently a difference in concentrations of imidacloprid between “homeowner products” and “commercial products”. The obvious difference of course is availability to homeowners of commercial products but the other one is in the lower concentration that you mentioned.

            Homeowner products are frequently less concentrated than commercial products. This is because commercial applicators should have more knowledge about safe use of these pesticides and access to PPE (Professional Protective Equipment) when applying it. Plus, the homeowner uses less product.

            For commercial applicators, imidacloprid is contained in several products and atconcentrations much higher than 1.47%. “The dose makes the poison” and having a less concentrated product available to homeowners can be “safer” for the uninformed to use. It also means less “left over” product when finished.

Read the Label

            Is 1.47% strong enough to use as a soil drench?  Look at the directions for use. Does it say you can use it as a soil drench for your purpose? A reliable manufacturer will want you to be successful, tell others about your success and use their products again. A reliable manufacturer will give you the right instructions and concentration that will be effective.

This formulation of imidacloprid allow for a soil drench of vegetables and fruit trees. It has 0.233% imidacloprid and the label tells you how to mix and apply it. If the label doesn't allow it, then by law it is not allowed.

            It’s up to you to read the directions and make sure this product is applied correctly as a soil drench and for your purposes. Make sure it is applied after the plant flowers in the spring to avoid “honeybee” problems which it clearly states on the label.

Getting Second Crop of Tomatoes in the Hot Desert

Q. Is it possible to get more tomatoes on my plants in the fall? What needs to be done to produce them?

Tomato was pruned back in late Summer to stimulate new growth and new flowering and fruit set when the temperature cools below 95F.

A. Yes, you can get a second crop from the existing plants by cutting existing plants back or start new plants directly in the garden from seed. Here’s how to do it.

Plant Seed

            If you plant seed directly in the garden to replace existing plants do it now. Plant an early variety from seed such as the ‘Early Girl’. Rake the surface of the soil to create some ridges and put a group of 3 to 4 seeds, 6 inches from the base of some existing plants you plan to remove. This is for shade. You only want one plant to remain from this group when starting them from seed.

            Cover each group of seed with a quarter inch layer of sand mixed with compost. Water the seeded areas by hand three or four times during the day while it’s hot. Reduce watering to once a day when the seedlings emerge. Remove all other seedlings in a group except the most vigorous. Lightly fertilize the remaining plant when it’s 2 inches tall. The Early Girl tomato plant should start flowering in about 50 –60 days.

Pruning Back

            When cutting back existing tomatoes make sure they are healthy. Cut them back sometime around early to mid-September when it’s no longer unbearably hot. Remove the top one third of the plant by cutting just above aside shoot. Spray the plants with a liquid fertilizer early in the morning. They should start producing flowers and fruit in about 3 to 4 weeks.

Separating Worms from Vermicast

Q. How do you easily separate earthworms from the castings. I raise them in a big pot.

A. There are three basic ways of separating earthworms; by pulling them to a new food source, using light to “herd” them, or screening the soil. Let’s get some “vermiculture” terminology out of the way first.

Red wigglers or other worms used in vermiculture can be separated from the vermicast physically by screening, food or herding with light.

            Vermiculture is the raising of surface-dwelling earthworms for the purpose of vermicomposting. Vermicomposting is using surface-dwelling worms to make compost rather than a traditional composting method. The end-product is not called “compost” but rather “vermicast”. Vermicast is basically “worm poop”. The proper way to talk about it might be, “I am making vermicast through vermiculture rather than composting.”

Screening Method

            All three of these methods require screening of the vermicast end product to remove worms and egg cases called “cocoons”. It’s faster to screen for renegade worms and cocoons than to rely on screening alone for separation but it can be done that way.

Food Method

            Putting “fresh worm food” in a pile for the worms to eat separates them. This method attracts them to one location where they can be transferred to a new location and the vermicast screened and collected. When they congregate around this new food source, remove them from the vermicast, transfer them, and begin the process all over again.

Herding Method

            The “herding” method uses light which they hate. Vermicast is dumped into a pile, the worms migrate away from the light as you screen the top of the vermicast. Always leave a thick bottom layer for worm migration. When finished, use the bottom layer full of worms as the “inoculation” for creating more vermicast.

What is Desert Horticulture?

Desert horticulture is a unique form of horticulture, very different from traditional horticulture in many ways. People who have gardened for many years in wet climates find themselves disoriented in desert climates. However, the laws of plant science have not changed, only how these laws are applied to the growing of plants.

Rainfall

Officially deserts should receive less than is of rainfall (4 cm) each year to be classified as a desert. However in a looser definition it has to do more with how much water plants could lose when irrigated. This involves both evaporation of water from nonliving surfaces combined with the transpiration of water lost from plants.

Irrigation is artificial rainfall. Desert plants respond to very quickly to rainfall and many times have evolved ways that keep them alive when rainfall is limited. When these rains come again, they spring to life. Drip irrigation is important in desert horticulture because it delivers this precious resource inexact amounts to plants and has the potential for conserving the most water of any form of irrigation.

When water is applied to native desert soils that have never been irrigated, rapid chemical and physical changes occur in many forms. Irrigated desert soils can damage plants, damage structures and cause many problems for the desert horticulturist.

Plants

Desert plants are uniquely tied to their climate. They respond to changes in their harsh climate that might threaten their lives.

Soils

Desert soils are unique because they develop under low rainfall conditions. There are oftentimes high in pH or alkaline in nature, salty, have very low organic content and contain a unique invertebrate and microbial community ready to flourish when water and organics are added.

Desert soils can be chemically and physically unstable when first irrigated because they have remained dry for so long. They are frequently rich in nutrients that have remained stable in this low rainfall environment for hundreds of years. Some of these high concentrations of minerals, like boron, sodium and chlorides can be toxic to plants. Others like sulfates can damage structures and other manmade contraptions in contact with this soil.

Sunlight

Sunlight intensity, the brightness of sunlight, in the desert can be quite strong. By some measurements, substantially stronger than sunlight in humid climates. Shade cloth that provides about 30% shade benefits many vegetables grown in direct sunlight.

Temperature

High temperatures are a hallmark of desert climates. It's one of the first things we think about when visiting the desert. The range in temperatures can be extreme in the desert, sometimes varying as much as nearly 75 ° F or more in a single day. Seasonally, temperatures might range as much as 100° F.

Shade is very important in desert climates. For humans and other animals, 100% shade can be extremely inviting on a hot summer day. But for plants, that rely on sunlight for a constant supply of energy, this is excessive. As an average, 30% shade is ideal for many flowering and fruiting plants. Plants that produce insignificant flowers and fruit may perform well under a higher percentage of shade.

Low Humidity

Low humidity does not sound like a big deal when growing plants. In fact, it is one of the reasons why plants grown in the desert have fewer disease problems than the same plants grown in a humid climate.

Salinity

Salts are common in desert soils and in some irrigation water.

Wind

Strong and erratic winds are a common feature of desert climates. Microbursts of winds approaching tornado speeds can be a common occurrence during cool spring weather hot summers.

Take Your Home Pest and Get Them Identified

Q. I spent days dealing with the green residue from a summer of thousands of midge infestation. We live near a pond, not sure if that is the reason for our problem. Wondering if they are in the plants in our yard and if we could spray something to stop them before the warm weather comes back in the spring. There are still a few holdouts even now.

A. I am curious about what you are calling “midges”. I know the word, but this term does not tell me which insect it might be. Without knowing exactly what this critter is makes it tough to understand what the effective control might be. Their exact Latin name is not necessary, but I think you need another set of eyes to identify them more accurately. There are some biological and organic controls that might work if its more accurately identified and I would hate to recommend a chemical spray if you don’t need it.

Proper Identification Leads to Using the Right Control Measure

            Catch some of these critters and put them in a jar with alcohol (clear vinegar will work in a pinch) and take them to the State Department of Agriculture in Las Vegas on East St. Louis. See if someone there has a more precise name for them. Phone ahead of time at (702) 668-4590 and see if there is someone in the office who might give you some ideas. While you’re at it, ask them what they would use for control. They have access to the state Entomologist in Sparks, Nevada, but it might take awhile to get it identified.

             Another place to take it is the Master Gardener help desk. Call 702-257-5555 and take them a sample in a glass jar and see if they can help get the right name for it and possible controls. Doesn’t need to be the exact insect ID name but close enough so we are on the same page.

            Once you find out what it is and get some ideas about how to control them, contact me again and let’s go from there.

Delay Heavy Pruning of Fruit Trees Until Winter

Q. My new trees (apple, plum, peach) were planted a month ago and appear healthy. I watched several YouTube videos and am nervously ready to trim these trees. Being nearly May and heat coming on, should I wait until next year or just do it now?  

Delay major pruning of any tree to the winter months. It is safer for the tree, it reduces sun damage, the form of the tree (if its deciduous) is easier to see.

A. I usually prune right after planting in January or February. My rule of thumb is 90% of my pruning is directed towards improving the structure of the tree and only 10% is concerned with production; the second year focuses 50% of my pruning efforts on the structure and 50 % toward  production and by the third year only about 10% focuses on the trees structure and 90%  on production.

Tree Architecture is Easier to See

            Each year the trees structure is evaluated but most pruning focuses on entering production no later than the third year of growth in the ground. Some older varieties may take longer than that. Do I keep a few fruit to savor earlier than this? Of course! But only a few. I’m encouraging as much good growth as possible and getting rid of unnecessary growth as early as possible.

Always Carry Your Hand Shears

            I always carry a sanitized and sharpened hand pruner on my walks through the Orchard any time of year. I never know when I’ll see something that needs my attention. Better to remove small amounts of unnecessary growth early in the season than wait until December or January and remove a large limb.

This is a locust tree that had too much pruning. The bark of this tree burned in the strong Mojave Desert sunlight. Be careful when you remove limbs from trees growing in the desert. Removing too much or removing at the wrong time of year can result is sunburn of the trunk and limbs of trees.

            Light pruning can be done now or anytime but in the Mojave Desert be careful of removing too much which can contribute to sunburn of the limbs and fruit. Since we are in late spring, wait until December or January to do any major pruning. You can  lightly prune fruit trees all year long if they need it but don’t remove too much. Summer pruning is done about now to older trees to keep them smaller but that’s for the experienced fruit tree grower.

Try "Wiggle" Trick After Planting Fruit Trees

Q. My newly planted fruit trees you told me to, "Check for root problems by bending the tree over and see if it wiggles in the soil."  How hard should I push?  When I push my tree, it does move in the soil, but I wouldn't say it “wiggles”.

A. The tree should be solid in the soil, and not “wiggle”, after it is planted. Staking helps but doesn’t replace proper planting. Moving the top of the tree back and forth (like a strong wind is blowing) says a lot about potential problems during the first year and future establishment.

"Wiggle" the Tree After Planting

            After the soil has settled from planting and watering, move the top of the tree back and forth (wiggle it), before staking, to see if it was planted too deep . Once staked, a tree is tough to “wiggle” and for you to make that determination.

            If your tree never leafed out or, if it did, the leaves promptly died, the tree was most likely planted too deep. A tree should not be planted more than ½ inch below the surrounding soil.

After planting this tree, it was "wiggled" or the stem moved back and forth before staking. Wiggling the tree shows where the roots are planted and how deep the tree is in the soil. If the tree is more than 1/2 inch too deep then it must be removed from the hole and replanted. Planting a fruit tree too deep can result in the tree dying from trunk diseases.

Plant the Same Depth Where it was Growing in the Container

            Plant the tree at the same depth it grew in the container or (if bare root) the same depth it grew in the field when harvested. When no soil is attached to the roots (bare root) look for a color change in the trunk separating below ground and above ground parts. A metal stake (or stakes), driven deep enough so it is in solid ground, and tied to the tree with stretchable, plastic tape a few times keeps the trunk and roots from moving.

All plants should be planted the same depth they were in the container. If they are "bare root" trees, there is a change in color on the trunk that will show you the depth it was growing in the field. It should be planted at the same depth. Not deeper or soil piled against the trunk. That will kill the tree!

Mistakes Made at Planting Time

            Mistakes I see frequently at planting time are planting trees too deep, planting too shallow (so roots are exposed after watering), not staking, and digging the planting hole too deep when there is no good reason for doing that. Some people don’t stake trees because they think its not necessary. Well, staking shouldn’t be necessary when the tree is small and there is no wind.

Bareroot trees have no soil attached to them. Container plants are easier to plant because you can see exactly how deep to plant. If you are not sure, look at the roots. The roots are growing immediately below the soil and grow deeper. Barely cover the roots when finished planting.

            When trees are planted correctly, and before they are staked, they should feel like they are solid in the ground when moved back and forth. Then stake them so the lower trunk and roots don’t move later on.

Wiggle, Wiggle, Wiggle

            “Wiggling” the tree from side to side (when it’s not yet staked) visually exposes trees that are planted too deep. Look down. The tree trunk makes a larger hole in the soil when its moved back and forth. That’s a sign the tree just may have been planted too deep.

            You know that old saying, “Dig a $50 hole for a $5 tree,” is still a valuable adage even if the money is wrong. 

Peach Tree Dropping Fruit

Q. I have a well-established, prolific peach tree. About this time every year it loses some of its immature fruit and I know that is normal. However, this year it's losing an abundance of fruit. I'm literally picking up 50-100 peaches a day. I have checked the irrigation and it seem to be fine. (drippers, 15 min per day, twice a day.)

A. I don’t like that you are applying water every day, twice a day in fact! Is there any way that can be changed to less often? That irrigation frequency sounds like watering a lawn or vegetable garden when it’s hot and windy out! I don’t know about the amount you are applying, but you are applying water way too often.

Peach trees will probably set less than 5% of the fruit that results from flowers. If you don't remove the fruit, the tree will do it for you. The end result is, what are the size of the peaches when you harvested? And how did they taste. Far more important to consider than fruit drop. Also, letting the soil become too wet or too dry will encourage fruit drop and loss. Change your irrigation practices!

What's Happening? 

Fruit trees should have water applied to them twice a week in May when growing alone in the desert and in most soils. The applied water should wet the roots to a depth of about 18 inches each time its watered.  

Sometimes people will ask me...how much mulch or woodchips should I have around my trees? Its like asking how far should you keep weeds from growing near a plant. The futher, the better for weeds. For mulch, at least to the dripline of the tree. But further is better!

For fruit trees growing in the desert, I like to see a layer of woodchips on the soil surface 3 to 4 inches deep. These woodchips provide a layer that protects the roots from getting too hot, conserves water, prevents most weeds from growing and helps keep the soil dark and rich.

Only a few months after applying wood chip mulch to the soil surface in the irrigated area you will see the color of the soil become darker. This is from the decomposing wood chips covering the soil. It decomposes and adds organic matter to the soil and you see worms flourish in those areas.

            I imagine the tree roots  are only growing about 2 inches deep if watering is this often. They should be growing 18 inches deep to anchor the tree in the soil. Roots like this are cycling back and forth between too dry, too hot or too wet. Roots can’t grow deeper because they are drowning (if you are watering a lot) or getting too hot and dry (if you aren’t watering enough). I need to know how many gallons you are applying, not the minutes, and where it’s being applied.

What to do? 

Cover all the soil under the tree’s canopy with 3 to 4 inches of woodchips. Apply water to the soil 12 inches from the tree trunk all the way to the edge of the canopy. This can be done by constructing a donut around the tree trunk 6 to 8 feet in diameter.

Irrigation donuts or moats around trees when they are small, are smaller. As the tree increases in size, the donut increases in size as well.

            Fill the inside of this donut with a 1-inch layer of compost with woodchips on top. Fill the inside of this donut with water once a day. At the end of August, begin watering every other day. At the end of September water every third day. By December you should be watering once a week.

Growing Tropical Trees in the Mojave Desert

Q. We want to plant some tropical trees and shrubs in our garden. I am wondering if I should turn the soil in the whole flower beds over and amend the soil OR I should only dig holes where the plants go and fill the holes with amended soil.

A. A lot depends on the soil that you have, but I  think you can amend the existing soil where these plants will grow and won’t need to amend the entire area. Keep tropical plants grouped together for planting and irrigating ease.

Organics Added to the Soil are Important

            Cover the area where these plants are growing with a thick woodchip surface layer (mulch) when you are finished. You will rely on the woodchips decomposing to improve the soil where roots will be growing over the next few months.

Basins, or donuts, around trees can be important to capture water if they are not on drip irrigation.

            After planting, surround each plant with a “donut” of soil about 3 to 4 inches deep. This “donut” acts as a water reservoir to get the applied water deeper in the soil. Smaller plants have smaller “donuts”. Bigger plants have bigger “donuts. Water daily the first few days after planting and before turning it over to an irrigation system.