Crimson King Maple Root Loss Needs Top Loss

Q. I have a pair of mature crimson king red maples in Arlington ma that are showing signs of stress due to recent construction close to them and coinciding drought their canopy has reached its limits to receive water easlily from rain or the surrounding irrigation that is in the lawn under them I was told fertilizer and lots of water should bring them back before pruning any suggestions would be appreciated 

Crimson King maple picture  from University of Arkansas Extension

A. I think water and fertilizer is pushing your luck this time of year. It is possible to lose quite a bit of roots and not have many canopy problems but that just depends on which roots were cut and how many. 

General rule of thumb is to correct root loss with decreasing the size of the canopy. Don’t have pictures so I would tell you to prune back the canopy ¼ to 1/3 by reducing the canopy size at the furthest distances from the roots. 

Trees have the most difficult time getting water to leaves and stems furthest from the roots. They show stress first...leaf scorch and limb dieback. This will probably mean you many have to “drop crotch” the canopy. If done by a good arborist, they should be able to maintain its beautiful characteristic shape and you will notice very little change in appearance except size.

Of course putting about an extra ½ inch of water under the canopy weekly beyond irrigating the 

grass will help because of the tree’s shallow roots. They aren't very drought tolerant due to their shallow roots.

I think Crimson King is a Norway maple.

Best Free Stone Peaches for the Desert

Q. I would like to know which freestone peaches are best for Las Vegas and are they readily available at our nurseries?

A. Generally speaking, the most reliable fruit trees for this area are available from local nurseries. Peaches should state on the plant tag if it is a cling-type or freestone. The trend in home gardening is towards freestone so most peaches and nurseries will carry freestone types.

            It can be fun to look at plants from the national retailers but be knowledgeable about what you want and what will work in this climate if you go plant shopping there. Sometimes you can find some real jewels. Sometimes you will find some real challenges as well.

            Fruit trees are in limited in quantities this year; worse than past years as the trend toward growing your own food has grown and inventories were sold out early. Nearly any peach will grow here. But the quality of fruit they produce will be different than the same fruit grown in other climates.

            There are literally hundreds of varieties to pick from. It is not possible to list them all and tell you which is the best. Rely on knowledgeable staff. Stay with standard size or so-called “semi dwarf” types if you are growing them in the ground.

            Big trees are not always the best. Select trees that are moderate in size and have branches growing from the trunks in many different directions and at locations along the trunk 30 inches from the top of the container or lower.

            Select miniature or genetic dwarf peach if you are growing them in a container. Generally speaking, full-sized trees have better quality fruit than miniatures or genetic dwarf.

For a start you can look at my recommended tree list by clicking here

Ideal Climate for Almond

Q. What is the ideal climate for almond tree. How can we give cooling to an almond planted outside. It is because if I take the almond plant  to India Kerala.

Thank you for your time and effort.

A. The tree will cool itself if it had water applied to the soil regularly. At air temperatures of 45C, plants will cool themselves to about 35C if the soil is kept moist.

Almond originates from Central Asia where temperatures can reach 40+C at daytime extremes. We have had almonds growing successfully at 48 to 50C in the Mojave Desert. I don’t think you will have a problem with summer temperatures.

The cooling you might need is for winter chilling hours because I think in Kerala you may not have enough winter chilling hours. Select an almond with the lowest winter chilling requirement. Almonds have a chilling requirement of around 300 to 500 hours of temperatures below 7C. Read more about chilling requirement below.

http://www.davewilson.com/product-information-general/special-topics/fruit-tree-chilling-requirement

It is worth trying and let me know how it does for you.

Jerusalem Sage May Need Some TLC

Q.  My phlomis plants have leaves that have died and some have yellow with brown tips. Should I cut it down in February? Should I increase the water? Do I just leave it alone? What causes the edge of the leaves to dry up?

A.  Commonly, this plant is called Jerusalem sage.  It grows like a weed in the Mediterranean region and has become somewhat of a pest in parts of England where it escaped from gardens and become a “weed”. 

            Judging from the pictures you sent, the newest growth looks great!  It’s some of the older growth which has yellowed or turned brown.  Cut the plant back to the ground just like you would lantana, and let it grow again.  It will.

Want to see what it looks like?

            Even though it has started to grow, you can do it now.  Next year cut it back in January just before it starts to grow.  Apply compost to the top of the soil around it in a 12-inch ring, 1 inch deep, to improve growth, color and flowering.  If it’s growing in rock, apply compost on top of the rock and wash it in with a hose.

            If a plant is going to be a weed it might as well be pretty and taste good!  This is both. Most people grow it as an ornamental because of its yellow flowers.  But it’s in the same family of plants as mint and basil so it smells and tastes good.  Use the leaves as a substitute for common sage; pull off fresh leaves, let them dry, put them in a plastic bag for storage and crush them directly when preparing stuffing or cooking meat.

            Our climate is not Mediterranean and our soils are worse than Mediterranean soils.  Grow Jerusalem sage as you would any other perennial vegetable or herb in our desert climate and soils.  Do not plant in locations where there is intense temperatures and mix compost into the soil at the time of planting in a ratio of 1 to 1.  

            My guess is the damage to the leaves is old, from winter cold temperatures and some watering problems perhaps.  Avoid growing it on the south and west sides in intense hot locations.  Water and fertilize as you would any other perennial vegetable or herb.  Pinch new growth for a fuller canopy and harvest young leaves for more intense flavor and aroma.

Pyrethrum Doesn't Kill Thrips

Q. I was advised to spray my nectarines and peaches with a garden pesticide containing pyrethrum to kill thrips. Would you still eat the fruit once this chemical has been applied? And if I spray it, will the fruit not be deformed?

Thrip damage to netarine.

A. If the label for this pesticide does not have fruit trees or gardens on the label, then it should not be used for that purpose. This is a legal response, not a technical response to your question.

            Nectarines, not peaches, are deformed and scarred mostly because of the feeding damage on the skin of the fruit by Western flower thrips. These insects are tiny but when there are hundreds of them all feeding on the skin of one nectarine, they rip and tear at this so badly that the fruit becomes deformed and scarred horribly. Killing off the thrips prevents fruit deformity and scarring.

            Strangely enough, thrips damage does not occur on peaches so they will not have to be sprayed. Evidently the hair on the peach skin is enough to interfere with the feeding damage by these extremely small, flying insects.

            By the way, thrips are so primitive they don’t have wings like most insects. They have “sticks” that come out of their body with hairs on them. They are very poor flyers and can’t travel very far.

/Thrip. Not my picture but don't remember where I got it.

            On the label of the pesticide it tells you how many days you must wait before picking fruit. This is called the “Re-Entry Period” or “Days before Harvest”.

Years ago I had to find out if the damage was because of thrips so I put this fine mesh insect netting around an apricot tree. The fruit was not damaged. It was due to thrips.

            There is a lot of science that goes into that label. It’s not guesswork. It does not mean that the pesticide is totally gone. It means that a reasonable amount of the pesticide has been degraded by our weather and the EPA has deemed it “safe to eat” if the fruit is washed before eating.

            As far as the insecticide goes, it is called a synthetic pyrethroid and does a good job killing most insects including those in the home. However, on thrips it does not do a great job. Spinosad is much better to use and organic to boot.

Doesn't say it in the common name but this contains spinosad.

            But Spinosad is lethal to bees so spray only when there are no flowers present in the tree or beneath it and bees have gone home for the day. This will be at dusk. Rotate this spray with Neem oil and soap sprays.

Qatar Coconut Palm Possible but Difficult

Q. I would like to know why coconut trees are not bearing coconuts in Qatar.

A. Probably it is not old enough. Given proper care and growing conditions, coconut palms produce their first fruit in six to ten years, taking 15 – 20 years to reach peak production. It will take longer if it is in poor health or stressed. Some coconut palms require cross pollination from another tree.

            On fertile soil, a tall coconut palm tree can yield up to 75 fruits per year, but more often yield less than 30 mainly due to poor management and fertilizer practices. I don’t think high temperatures of Qatar will be a problem for tree survival but low temperatures will. Refrigerator temperatures for long periods of time outside may discourage coconut production.

            Your coconut palm will have difficulty with new growth during dry weather. The fronds may have trouble opening so if they do, hose them down with water. The fronds will also brown or scorch on the tips, more so than in tropical humid climates. They may not look the best.

            If your temperatures get much below 10° C (refrigerator temperature) and stay there for a while they may not produce fruit. Also, some coconut palms may require cross pollination to set fruit much like corn does. Some of the specialty coconut palm trees, particularly the dwarf types, are thought to be self-fertile and may set fruit on their own.

Dwarf coconut palm in plastic container

            Coconut palm roots are very similar to grass roots except bigger. A large container is needed if container grown because they need to support themselves as they get taller and require a large enough area to grow this root system. Under natural rainfall, these roots could spread perhaps 30 feet from the trunk.

            They like water but do not keep the soil around them constantly wet. Keeping the fruit continuously wet works for germination of the seed but not once they start growing.

            So, in short, protect it if temperatures drop close to refrigerator temperature and keep it as close to 50 or 55° as you can during these cold periods. Summer temperatures shouldn’t be a problem unless it’s setting fruit during these temperatures. It will probably drop fruit. The fronds may not look the best due to high temperatures, low humidity, and wind.

Yuccas Are More Sensitive Than You Might Think

Q. I have a five-foot Yucca tree that I cannot get to be disease free after two years of trying.  I have tried several insecticides and fungicides. I hope you can identify the problem from the picture.

A. The Yucca leaves are scorching or turning brownish white in the middle, at the bend where the leaf is curving down. This is not a problem you can correct by treating with insecticides or fungicides.

            This is an ornamental Yucca called Spanish dagger with flat leaves coming from the trunk and curving slightly downward. You would think that yuccas would be a plant not requiring much care in the Mojave Desert. Well, this one does. It is native to coastal Carolinas, Georgia, Florida and Alabama.

            This is a cultural management problem. It should be addressed by transplanting it to a new, protected location and adding amendments the soil at the time of planting. Water it more like a palm tree than a cactus.

            Although classified as a disease, it is not caused by anything biological so pesticides won’t do any good. This problem is more correctly classified as “leaf scorch”. It is a soil/planting location/water management problem.

            Don’t plant this Yucca like you would yuccas that grow easily in desert environments. This particular Yucca prefers protection from the hot, late afternoon sun and grown in richer soils, soils amended with compost at the time of planting, and not surrounded by rock mulch.

            What to do now? Move it to a new location which gives it protection from direct, late afternoon sun. If it is surrounded by rock mulch, get rid of it. With a posthole digger or soil auger make several vertical chimneys in the soil about two feet deep and 18 inches from the trunk. Pack these vertical chimneys with compost and then soak them with water.

            Water this plant like a normal landscape plant with good drainage and make sure it is watered on four different sides with enough water each time to percolate 18 inches deep. 

Magic! My Rose Bush Suddenly Has Small White Flowers

Q. I have a rose bush that did well for years but now it only produces small white roses. What happened?

A. The top of your rose bush died but the rootstock survived. Two different plants are combined into one plant through a propagation technique called budding. The top of the plant is desired for its beautiful flowers. The rootstock is selected for a variety of reasons but performs better in soils than the top of the plant if it had roots.

            All rose bushes available commercially are grown on rootstocks. These rootstocks are also roses but their flowers are a different color and size than the rose you selected. In your particular case, the rootstock was perhaps Rosa odorata, a rose that produces small white flowers.

            If you don’t like the plant then remove it and replace it with a variety that grows well in our hot, desert climate. On the website of Weeks Roses, they publish a list of roses by flower color and rose type that perform well in our hot desert. Or talk to some neighbors who love roses and know what they planted.

Roses for the Desert Southwest

            Be careful when pruning roses. Prune them in January but do not cut them back too short. Pruning roses short cause the rootstock to grow vigorously and send up suckers that could dominate an overly pruned rose bush. And remove all suckers coming from the rootstock.

            I noticed in your picture that your roses were surrounded by rock mulch. No, no, no. Roses do not like rock mulch. Get rid of the rock and lay down some compost and cover the compost with three inches of wood chip mulch instead. They will be much happier. 

Cape Honeysuckle Is All Confused. Or Is It?

Q. Our cape honeysuckle has done well, even bloomed during the past winters. But this time of year it always stops blooming. Is there something I should be doing or not doing to keep it flowering through the summer?

Its winter for cryin out loud. Why are you in bloom, ag shame?

A. Cape honeysuckle is from South Africa, below the equator, so it's bloom time is the opposite of ours; blooms in the winter and not during the summer. Another plant from South Africa, African sumac, does the same thing.

No flowers now. Must be spring or jost sommer.

            Cape honeysuckle is a great plant for the dry desert because it is not as invasive here as it can be in wet climates. The only drawback is it being winter tender at temperatures around 25 degrees F.

            Watch for freezing damage during particularly cold winters or in cold landscape microclimates. Much like Bougainvillea, if the base is protected with mulch during the winter it will grow back again from the protected base.

Apricot Tree with Pink Leaves!

Q. We planted a bare root tree Blenheim apricot earlier this year and it's put out these pink leaves in the spring. Is that a sign that it will flower or fruit or that we are watering too much? 

New growth that is red on some varieties of apricot like Blenheim (Royal)

A. No, that's a typical color of new growth for some apricots. It doesn't indicate anything except new, juvenile growth.

            Fertilize it once a year in January. Compost is best. If you use woodchip mulch on the soil surface beneath the tree, you can get by with using mineral fertilizers. Otherwise, use compost as a combination fertilizer and for soil improvement.

            Make sure the tree is getting enough water. Lots of new growth in the spring is a good indicator that it is. A new tree like that should get at least 5 gallons of water every time you irrigate it. Slowly work your way up to 30 gallons by the time it's is 5 to 6 years old. Blenheim is a good apricot in our climate and I'm sure you will enjoy it if you like apricots.

You Ever Heard of Guttation?

Q. I have never had a problem with pests on my little leaf Cordia plant before. I found a small round liquid balls on the edge of the leaf. What am I dealing with here? 

Guttational water from Cordia.

A. Great pictures and they help a lot. It’s nothing to worry about but it’s very interesting so I want to talk about it.

            I am taking an educated guess that this is water released from small openings on the leaf edges called hydathodes. The release of excess water from inside the plant is called guttation. Guttation is normal and it happens under certain conditions.

            . Basically, small plants can push a lot of water inside them through a mechanism called root pressure. Root pressure takes water from the surrounding soil, if there's plenty of it, and pushes it inside the plant.

            Sometimes the water pressure inside the plant can be so great that it needs to release some of this excess water. Many plants have specialized openings on leaf edges called hydathodes and this is where the water comes out. Technically, the process of taking excess water inside the plant and releasing it through hydathodes is called guttation.

Whipping the greens for the US Open. from https://golfcontentnetwork.com/news/u-s-open/u-s-open-theres-nothing-quite-like-oakmont/ 

            It can happen on grasses a lot. Golf course superintendents are concerned about this phenomenon because the water coming from the plant is full of sugars. It can be a rich breeding ground for grass diseases. If this water rich with sugars stays on the leaf surface for several hours, disease problems can be a reality.

            Superintendents, years ago, used bamboo poles to “whip the greens” and remove this excess water from the leaf blades. It was thought by doing this the water was removed from the leaves and disease problems were reduced as well. Most now use a quick pulse of irrigation water instead.

            So, what does this have to do with you and your little leaf Cordia? If this is guttational water, the plant is telling you not to water so often. The soil is full of water. Make sure you give it a "rest period" without water before the next irrigation. Other than that, nothing to worry about.

Rhubarb Growing in the Hot Desert?

Q. I would like to grow my own rhubarb. Could you tell me where I can find the plant or the bulb, and when would be a good season to start?

Not my picture of rhubarb but I figured some readers have never seen it. From Wikipedia By Dieter Weber (User:Uellue) - own work, photo taken in a private garden in Kiel, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=743387 

A. Rhubarb can be grown in our climate but it is commonly grown in more northerly states including the Midwest, upper Midwest, Pacific Northwest and New England. It is less commonly found in warmer climates. So, it can be tricky to grow here.

            It is technically classified as an herbaceous perennial which means it’s large leaves and fleshy petioles comes from underground rhizomes, much like iris, artichokes and asparagus. All the top growth freezes back to the ground with the first hard frost. If it doesn’t freeze back in our climate, cut it to the ground in late winter.

Rhubarb rhizome for showing growth from  http://www.rhubarbinfo.com/propagating

            Seeds are available but start it from a good-sized rhizome instead. They are a bit pricey. Order them online from a reliable seed company.

            Rhubarb will struggle in our heat. There are complaints from people that it doesn’t taste the same when grown in cool climates. Probably true. Grow it on the north or east side of a building and keep it out of late, hot afternoon sunlight. It needs plenty of sunlight in the morning, but not the afternoon.

            Amend the soil with quality compost at the time of planting. Mix compost with your existing landscape soil at a rate of 1:1 by volume or use a bagged, commercial soil planting mix amended with compost.

            Never cover the soil with rock mulch or plastic but use 2 to 3 inches of wood chips instead. Fertilize it with compost or a lawn fertilizer in late December to mid-January. It comes out of the ground early.

            The leaves are toxic so cut off the leaves and compost them. The leaf stems or petioles are what people eat provided it's cooked with a lot of sugar. 

Don't Be Afraid to Prune Small Trees

Q. I have some stick sized trees growing very well. Some are about 12" to 18" tall. The leaves are around the bottom of the stick and none at the top. Should I cut the stick off down to the leaves?

A. Yes, if you think it's dead cut it back to the leaves. When new shoots begin to grow taller than 1 foot, remove all but one if you want a single stemmed tree. If you want a multi-trunked tree remove all but three or five, and leave an odd number growing. If you can prune it with a hand shears then prune any time of year.

            Lightly fertilize it every couple months to push new growth. If this tree is tender to winter freezing temperatures, don't fertilize after an August 1.

Is MiracleGro Really All That Great?

Q. Is Miracle grow all it's made to be?  I haven't seen any results yet after I sprayed it on my plants.

A. If your plants are in great shape to begin with you won’t see any results from MiracleGro fertilizer applied to the leaves or any other product for that matter. Applying a liquid fertilizer to the leaves gets fertilizer inside the plant faster so results, if there are any, will be seen sooner than applying a fertilizer to the soil. That’s the primary reason for using it.

Peters is an alternative for Miracle Gro. It has an outstanding commercial reputation among greenhouse growers. i don't know how good the homeowner product is.

             I used several types of powdered, fertilizers mixed with water and applied to the leaves because I’m curious about them. These include MiracleGro, Peters, and Grow More. Honestly, I have never seen much difference in any of them. If I were to lean toward a product in that group it would probably be Grow More because it’s the least expensive.

Grow More has a very good line of water soluble fertilizers that are not as expensive and have a great reputation particularly among marjuana producers.

            There are steps I would recommend when using any of these products to get the best results. Use distilled water. The effectiveness of liquid fertilizers has a lot to do with the quality of the water used. Our tap water is alkaline. Our tap water can cause problems with foliar fertilizers.

            Add a spray surfactant to the spray mix before applying it. Spray surfactant is a fancy term telling you to add something to the mix to help the fertilizer get inside the leaf. The leaf is covered with waxes and using a spray surfactant helps the fertilizer get inside.

Use distilled water rather than tap water if your tap water has a bad reputation or has some pH problems like it does in Las Vegas. Distilled water has a ph of 7 and wont have problems with micronutrients become unavailable.

            You can buy commercial spray surfactants called “wetting agents” or use a high-quality soap such as a liquid Castile type. Use about 1 tablespoon in a gallon of spray mix.

            Spray this mixture on the leaves, both front and back, only until the surface of the leaf is moist. No more than this.

EZ wet is a very gentle wetting agent/surfactant  that helps fertilizer nutrients move inside the leaves. Liquid Castile soaps are also good. Stay away from dishwashing liquids because they are hard on plants and have personal care products in them now.

            Use it all up. Don’t store this spray solution. Make a new batch for the next time you spray. 

Brown Branches Are Dead Branches?

Q. Do brown branches denote "deadness" on a tree in the spring or can they be brought back somehow?

Dead branch in purple leaf Plum that will not come back because it is truly dead.

Italian cypress with brown branches that appeared dad but are still alive. Nothing will grow from these brown branches anymore even though they are alive.

A. Brown does not always mean a branch is dead. Some tree branches are more brittle than others. For instance, fig, persimmon and pomegranate branches can be quite brittle compared to apple and peach.

            The usual method I use to see if a branch is dead is to bend it. Many branches of trees may look brown and dead but are quite supple when bent. Supple and bending denotes it’s still alive. Other trees have branches which are alive but can snap easily when bent. In cases like this I scrape the bark with my thumbnail or a knife to see if the wood is green under its “brownness”.

            Remember, some plants are slow to leaf out in the spring. Wait for new growth and prune out whatever might be dead. I sometimes get confused as well when winter or early spring pruning.

White Cotton on New Growth of Ash

Q. I have a 6-8 yr. old ash that has this white powdery looking substance on the newer growth. Can you tell me what it is and how to eliminate it. Photo attached.

Unknown white cottony insect at base of new ash growth.

Another image of white cottony insect at base of new growth on ash

A. I have to admit I put this on a back burner because I wasn't quite sure what was going on. I have seen this on vegetables and herbs but never on the new growth of ornamental trees. It is most likely an insect problem.

These insects are feeding on the soft, succulent new growth. If you touch this white fluffy substance on these shoots I think you will see these insects beneath it. The problem I had was what to call these insects. At first I thought it was woolly Apple aphid which makes a lot of sense in the cool time of the year when there is new growth.

But what troubled me was that I have never seen woolly Apple aphid in Las Vegas before. I have seen it in other cooler climates.

See some pictures of Wally apple aphid

Secondly, the pattern that they are feeding in does not typically fit woolly Apple aphid. They don't usually feed all along the new growth. They are typically clustered at the bottom of the new growth. Until you tell me differently, I am going to stick with woolly Apple aphid or another kind of insect that feeds on the sap of newer, soft, succulent growth.

They are easy to control or even ignore. You could take a hose and a nozzle and knock them off with a powerful, directed spray on the foliage. If you want to be more aggressive, you could use a soap and water mixture and do the same thing with a hose and applicator. If they really bother you, you could nuke them by applying the Bayer insecticide for trees and shrubs and apply it to the soil surrounding the roots. In my opinion that is overkill. See if they continued to be a problem or not. Aphids typically become less of a problem as temperatures get hotter.

Stop the Quail From Eating Apricot Leaves!

Q. How do you stop Gambel's quail from eating apricot tree leaves? They never touched my 3-year-old tree until near the end of the last growing season then they swarmed the tree and chewed at everything that was green. These little fish poops ate all melon plant sprouts yesterday as well. I tried hanging CD's, strips of tin foil to no avail.

Bird pecked peaches at the Orchard

A. About the only thing I can suggest is giving them an alternative to munch on or cage them out using bird netting. I am sure there are lots of suggestions from people like spraying garlic, hanging pie tins or DVD’s to scare them but in my experience these tricks do not work for very long or not at all.

Electronic bird scaring device used at the Orchard. It would work for about two weeks. After that, the birds got used to it.

            Birds in general can be a real problem, particularly to the fruit. The other option is to let them eat the leaves and let the tree replace what is lost. Once you get past spring, hopefully, they will move on to other more tender leaves at your neighbors.

Too Much Shade on Tomatoes Equals No or Poor Fruit

Q. We are growing the Celebrity variety of tomatoes in our garden here in Las Vegas and decided to cover them this year with a mesh tarp for shade because the sun has scorched them in the past.  However, we noticed the vines are growing but the tomatoes are not very big and they are not ripening like they usually do.  Are they supposed to have complete sun? What do you suggest?

Providing too much shade causes poor growth and reduced fruit or flower production or none! 30% shade vs 60% shade.

A. The amount of shade that you provide to tomatoes is critical for continued production of fruit. Shade cloth is typically categorized by the percent of shade that it provides. For flowering plants you should provide no more than 30 to 40% shade or they may stop flowering and setting fruit. Plants that do not flower can handle more shade, up to about 50 or 60%.

            You didn't tell me what percent shade you are giving tomatoes but I suspect it's too much. Light shade, 20 to 40%, is hard to find locally. Usually you have to order light shade for crops. You can provide shade by also using lathe instead of shade cloth.

            In northern climates we used to use snow fence. To get 50% shade, remove every other lathe from a solid ceiling of lathe. To get 25% shade, remove two and leave one. Chain-link fence with PVC slats gives you about 75% shade. I think you get the picture.

Remove Suckers from the Base of Citrus

Q. You mentioned that citrus trees are often grafted. Are full size trees grafted like dwarf trees? Do I need to remove anything? The trees are about five feet tall. Will I have more success getting fruit from full size trees?

Remove suckers like these from the base of small trees as soon as you see them.This fruit tree is watered with drip irrigation from in-line tubing. Wood chip mulch is covering the soil.The tree was planted bare root and painted with white wash to prevent sunburn.

A. All citrus bought from a nursery are grafted, full size trees as well as trees sold as dwarf or semi dwarf. Seldom are they grown on their own roots for a variety of reasons. The most common is because of our cold winter climate and protecting the rootstock from freezing. Some of this benefit from freezing is passed on to the rest of the tree.

Root stock dogleg on grafted fruit tree.

            Fruit produced from dwarf trees can be the same size as standard size trees if the tree is managed properly. If you look at the bottom of the tree you will see a “dogleg” where the top tree was grafted to the to the roots of a different tree. You will see this dogleg on many ornamental trees as well.

            Anything growing from below this “dogleg” (on the rootstock) should be removed as soon as you see new growth. Young trees frequently “sucker” from this rootstock and these suckers must be removed. Pulling them off rather than cutting them is better. As the tree gets older, it frequently stops suckering as much.

            Enjoy what you can. Citrus is “iffy” in our climate. Some years you will have fruit, other years you will not. Some years they may freeze to the ground and other years sail through the winter without damage. 

Avocados in the Las Vegas Desert?

Q. I am trying to grow an avocado tree.  I have it in a container and it's now 22 inches tall.  When is the best time to transplant and what is the best way to take care of it in our desert?

A. As you are probably aware, avocados are “iffy” in the Las Vegas climate. Probably a little worse than citrus regarding surviving winter cold. It depends on which avocado you are growing. 

            With that said, I would put the container in a protected area away from extreme cold during the coldest part of this coming winter. Around the first week of March, I would plant it in the ground. Make sure you amend the soil and do not fertilize it after August 1.

http://xtremehorticulture.blogspot.com/2014/01/solutions-for-home-avocado-production.htm
lhttp://xtremehorticulture.blogspot.com/2016/03/avocados-for-cold-desert.html

Daily Watering of Young Lemon Tree a Good Idea?

Q. I'm considering watering my little lemon tree every day during the summer months. Is this good or bad? The tree dropped two-thirds of it's leaves a month after planting. That was three months ago. It has stabilized, and I currently water it every other day on a slow drip. (4 gallons per watering) Should I water every day in June, July, and August because of the 100+ temps?

A. I have noticed some problems with citrus the first year after planting from containers into the soil. There was a lot of relief yellowing, leaf scorch, leaf drop and some dieback. This happened even though there was wood chip mulch at their base. Once small amounts of water were applied daily they did quite a bit better during the summer.

You will not have a problem watering every day if the soil drains water quickly. You will have a problem watering daily if the soil holds water for a long time. You might see some advantage to watering with small amounts of water every day. I see that sometimes on very young citrus but only for the first year after planting. I'm sorry to say, "it just depends…".

If you have not done it, try applying 3 to 4 inches of wood chips around the bottom of the tree and you should be able to water every other day with no problems even on the hottest days.

How Important Are Chilling Hours for Fruit Trees?

Q. This is really great information that you put on your blog!! Thank you so much for doing this, and it gives me a bit more hope about expanding my home orchard in Phoenix. 

http://xtremehorticulture.blogspot.com/2015/11/special-fruit-tree-orders-no-longer.html

http://xtremehorticulture.blogspot.com/2011/04/recommended-fruit-tree-varieties-for.html

How many chill hours are you getting where you are located? Specifically related to Pluots, you are recommending some with some pretty high chill hours, such as the Flavor Supreme which is listed on DWN as 700-800 chill hours. But as you mentioned above that may have a lot to do with location and micro climate.

Also for Apples, Pink Lady is a pretty late ripener, and I’ve heard that late harvest don’t do as well in the extreme heat of Phoenix, something similar to where you live. But again, I'm hoping the placing them is certain cooler places within my backyard and trying to create a micro climate that is a bit more forgiving to these fruits could have a large impact as well.

Would love to hear you take on the points point. Thanks again for putting some much time into this.

A. Thank you for appreciating the hundreds of hours that it took over a period of one and a half decades to put this list together. Many kudos to the Master Gardener volunteers who supported it.  I will try to address each of your questions separately.

            Most of the trees used were donations by Dave a Wilson Nursery, Tom Spellman in particular, who worked with us since 1996. This orchard is located in North Las Vegas Nevada at right about 2000 foot elevation.

            The orchard is exposed to the North West by cold winter winds which helps explain why citrus was not included on this list even though it was tried. Las Vegas is not citrus country but many people further south in the Valley have had success with some citrus and even limes and blood orange in warm microclimates.

            Our chilling hours are somewhere between 300 to 400 hours per year. You are exactly right. If you take chilling hours literally many of the recommended trees should not produce in this climate yet they have for over 15, now going on 20, years. Some of these so-called high chilling hours tree fruits have shown no sign of a lack in chilling hours.

            Tom Spellman was the first person to bring this idea to light for me. It challenges many preconceived ideas about chilling hours and there has been much speculation and even disbelief in this information.

            Personally, I believe that chilling hours are more important in some types of fruit and even some varieties than others. Is chilling hours important? Yes, definitely. Have we followed chilling hour recommendations to literally? Yes, definitely.

            Too many, Phoenix and Las Vegas have similar climates if you don't live in either of these locations. You and I both know that as far from the truth! Phoenix is a totally different animal from Las Vegas but I believe there is a wide variation in how plants view this difference. I believe most apples are more prone to chilling hours than peaches, nectarines, apricots and plums and their crosses.

            I don't know all pink lady apple performs in Phoenix but it is an outstanding Apple in the Las Vegas area. Like pomegranates, this particular Apple seems to have better flavor quality as temperatures drop. In our harsh desert climate it seems to develop a thicker, tougher skin but the flavor quality of the "meat" is superior. It is worth giving a try in Phoenix, Yuma, Parker, Bullhead or Lake Havasu.

            I think planting apples in areas of the landscape that avoid the late afternoon sun is a good idea. Contrary to some information out there, if your soil has lower amounts of organics in it, amend it with compost at the time of planting. I also believe you will see huge benefits if the soil is covered with wood chip mulch under its canopy to a depth of at least 4 inches.

            Keep the mulch away from the trunk for the first five years of the trees life to avoid collar rot. If rabbits are problems, protect the tree from rabbit damage with 1 inch hexagon with chicken wire for the first five years as well.

Furry White Things on My Myers Lemon Tree

Q. Last year we bought a Myers lemon and planted it in a large pot. We got more than 30 lemons off this little tree. I noticed a lot of sap near the base of the tree, then a bunch of furry little things on the trunk and some branches. They scrape off easily. I’m guessing they are the cause of the sap.

Cottony cushion scale on lemon

More of the same

A. You are right. This is cottony cushion scale, an insect, on your lemon tree. Those little furry things are homes to the scale insect. They live under those furry things where they are protected from pesticides and predators.

            Once in a while they come out and build a larger, furry home or find a mate. When they do, this is called their “crawler” stage, when they are most vulnerable to pesticides and predators.

            What’s interesting are the ants that you didn’t mention. These small, scale insects feed on the sugary sap inside the tree. While feeding on this sugary sap, a sugary concoction comes out the other end which some ants love.

            These ants move these insects to new growth in the spring where feeding is a lot easier than at the tough, woody base of the tree. In these new locations, ants “herd” them like cattle and protect them from marauders.

            From your picture it doesn’t look like you have very many on this tree yet. Take some alcohol and a cotton swab and dab them off. If there were lots of them you could spray horticultural oil several times during the year, particularly during tree growth periods.

            These oils suffocate the crawlers and keep it from spreading while the older ones eventually die off. Apply these oils three or four times during the year at times when temperatures are cool. By the way, it also helps a lot to control any ants in the area.