Follow Your Dog with a Bucket of Water

Q. I have two large dogs that use my backyard as their bathroom. They cause yellow spots that turn completely bare and kill the grass. Are there any grasses resistant to animal urine?

Dog urine damage to a lawn is usually surrounded with grass which is darker green and taller because of the diluted urea fertilizer contained in urine

A. There are no lawn grasses totally resistant to dog urine. The high concentration of "salts" in the urine is causing the damage.

These salts are actually "fertilizer" salts, not bad salts such as table salt. There is just too much of it. The salts are so concentrated that the grass is burned or killed in a 6 to 8-inch spot.

If you look closely at "dog damage" to a lawn, it looks very different from brown spots caused by diseases or insects. Insect and disease damage does not cause the grass to become dark green or grow faster around the edge of the damage. Dog urine does!

Salts from the urine become diluted in the soil further from the “point of impact”. Once diluted enough, salts from the urine act as a fertilizer and turn the grass dark green and push new growth.

The key to decreasing urine damage is the same as too much applied fertilizer. Dilution. Drenching the spot with water and diluting the salts is the simplest way to decrease damage to the lawn.

I know this might be a hassle and look a little odd to your neighbors but if you follow the dog around with a bucket of water and dump it on the urine spot immediately after it is done, you have a good chance of reducing or preventing damage.

Now, if you could just train your dogs to do it evenly over the lawn and turn on the sprinklers.

Wormy Apples Pest Problems Vary with Regions

Q. I have a Fuji semi-dwarf apple tree that is about 23 yrs old in Kingman, AZ. The last few years I’ve had a terrible problem with worms in the apples. I clean up all the leaves after they fall and remove any apples that don’t fall. I  I spray dormant oil right before the flowers buds emerge or sooner and spray all around the area including on the grape vines nearby. I have wood chip mulch about an 8 foot diameter around the trunk. I’ve even sprayed Neem oil once when the apples are about the size of marbles but to no avail. Now I’m wondering whether I should remove the wood chip mulch as this seems to be the only thing left to try other than continual spraying or trying stronger chemical type sprays which I’d rather not do. What do you recommend?

A. Most likely this is codling moth and they attack the fruit several times during the year. Codling moth is an international pest of apples and pears. Their emergence coincides with rising temperatures and if you do not get control of the first flight they can multiply rapidly and each new generation can bet worse. 

Codling moth on immature pear fruit in Afghanistan

Codling moth damage on apple in North Las Vegas, NV

I am getting ready to begin writing up how to use pheromone traps for eliminating codling moth, rather than pesticides, in backyard and small scale operations if codling moth is not a huge problem in the area. I may also offer some classes on how to use them. I have been trapping insect pests like these with sticky cards and traps for years. They can be a very powerful tool for insect management.

If codling moth is a huge problem in your area, this might not work for you but it is worth a try. Stay posted and follow me on my blog for more information.

Tree Died. Planting in the Same Hole.

Q. I have a major borer problem with my nectarine tree. I will be removing it and replanting. Do I need to treat the soil before I plant another tree?

A. No. The borers that are problems in our climate (Pacific flatheaded borer or Flatheaded apple tree borer) do not enter the soil during any part of their life cycle. The borer you may be thinking of is the peach tree borer which we do not have in Southern Nevada but is common in more northern climates. 

Adult Pacific flat headed borer picture from Oregon State University

The peach tree borer does not actually enter the ground either but can be found low on the trunk near the soil level which makes you think it does. Both of these borers spend their entire life cycle either in the air as a beetle (our borers) or a moth (peach tree borer) in flight seeking a mate and looking for food to sustain itself until it can reproduce. The rest of the time is either as an egg laid on limbs or the trunk or larva tunneling and eating in sapwood where it can find carbohydrates for nourishment and growth. The final stage is pupal, also inside the tree, where it transforms from larva to adult beetle or moth.

One of the flat headed borers in a damaged branch of peach

Control by chemicals is not very effective for our borer since we don’t know when it flies or where it lands until we see damage. Having said that, there is one chemical that is very effective for controlling borers that are inside the tree and it is labeled for fruit trees. The chemical name is

One of the products recommended for borer control containing imidacloprid

imidacloprid. It comes as several different trade or label names. One of the common names for homeowners is a Bayer product found in many local stores and nurseries. It is a systemic insecticide that moves up inside the tree killing insects that are feeding on the interior. The claim is for 12 month protection using this product. Personally, I have a problem applying systemic insecticides that last 12 months on plants which produce fruit that I'm going to eat in less than 12 months. But it is labeled to do this.

Instead I recommend that we focus on prevention by protecting trees like peach and nectarine from sun damage to the limbs, We do this by keeping the canopy full enough to shade these limbs or painting limbs with whitewash to reduce sun damage by intense sunlight. Sun damage seems to attract the adults and their egg-laying. 

Midsummer die back of peach limbs due to progressive borer damage.

On older trees, damage from these insects might be over several years before visual signs of damage appear. At advanced stages of attack over several years, we see limbs dying in midsummer. Early signs of damage can be seen the day after a good rainfall when brown colored sap oozes from damaged areas.

Sap coming from peach limb due to borer activity

During early stages of damage we can remove the outer bark of damaged areas with a sharp knife exposing where they are living and feeding and revealing them to potential predators and exposing them to the elements. When this kind of practice is done on a regular basis we might see about 80% of the damaged trees recover until the next onslaught. Borers in peaches and nectarines are the usual reason these trees seldom survive past 20 years of age.

Tropical Themed Landscapes Possible in the Desert

Q. I have a pool that is being built and we're at the final stages of it being done. We are trying to create a tropical theme around the pool and most tropical plants don't do well in the desert. Do you have any suggestions? 

A. There is no reason you cannot have a tropical or Hawaiian theme around your pool using either desert plants or plants that thrive in our climate. There are dozens of of desert plants that resemble tropical plants and even some plants that grow easily in both climates.

Let me give you a list of some plant materials. There are so many to pick from that will fit into this theme. This just came off of the top of my head.

Some of the tropical look has to do with planting density. This area should be densely planted and use at least plants from three different size categories. Use more size categories if it's a larger area.

Be careful of focal points. Don't have too many of them but use plant color or dramatic changes in plant texture to pull the eye to a focal point. The focal point can be a waterfall, water feature, spa area, entry/exit of from the pool, etc. designing an area should make use of continuity and rhythm through plant repetition this is usually done through plant texture or color.

There are a few landscape architects and designers who read my blog. I am neither. Perhaps they will chime in with some pointers as well.Don't be shy and please let readers know who you are and how to get a hold of you.

Trees

Mesquite. Any of the Mesquite trees look tropical.

Bottlebrush

California pepper

Acacia, some of the smaller Acacia

Windmill Palm, Mediterranean fan palm

Larger Shrubs

desert bird of paradise

Rose of Sharon (hibiscus)

Small Shrubs

Daylilies

Aloe

Nandina or heavenly bamboo

Bottlebrush

Mock Orange¶

ornamental grasses

Lantana

Vines

Carolina Jessamine

Star Jasmine

Bougainvillea (freezes back each year)

Groundcovers

Myoporum, sometimes called Australian Racer

Star Jasmine

Hearts and Flowers

Bougainvillea

Hen and chicks

Gopher plant

Perennials

Agapanthus

Amaryllis

Hollyhocks

Red Hot Poker

Canna lilies

Annuals

Vinca or periwinkle

Alyssum

Geranium

Celosia

Nasturtium

Portulaca

Pruning Miniature Peach Is a Little Different. I can help.

Q. Do you know of any person, to be paid, who will come to my home and prune two dwarf peach trees? I am 84 (widow) and really don't know how to prune these trees. I have tried for 5 years now and  know what I  do  is wrong; I need help. I have asked our landscapers (live in a condominium association) and they don't have any one in mind.


Please, do you have any suggestions as to where and how I might obtain help?

Miniature peach requiring pruning

A. I can help you with that but you must agree to learn how to do it. I do not do it as a landscaper or a service company but I will help you learn how to do it for yourself. 

If these are miniature peaches, they do require a different way of pruning than peaches that are kept small through pruning. First, we make sure branches on the lower part of the trunk will not touch the ground when they are loaded with fruit. We will focus on thinning out some of the branches so that there is better light penetration inside the canopy. Lastly, we will thin out the new growth so that there is fewer of them. You will be required to thin the fruit in March so that the remaining fruit becomes larger and higher-quality. If you need me to show you how, I can do that as well when that time comes.

Pruning of peach should be done before February 1 in our climate. If you are interested, I'll be happy to show you how. It will be within your budget. You should have an appropriate pruning shears and a small loppers. I will bring mine but you should have your own. If you don't have tools or the appropriate ones, let me know and I will bring good ones for you that are reasonably priced and you can reimburse me.

When to Prune/Protect Myers Lemon Depends On…

Q.When is the best time to prune a Meyer lemon tree that is planted outside and should they be covered when the temperature goes below freezing?

A. First of all, citrus does not require a lot of pruning unlike some other fruit trees. You would focus on removing crossed branches, broken branches or branches too close together. Generally speaking, prune citrus right after you harvest the fruit. Myers lemon may begin flowering in January or February and that becomes a bit late because the fruit will not finish until December of the same year, 10 months later.

Flowers of Myers lemon

This is why it is important to remove the fruit on Myers lemon by the end of December or it may interfere with flowering the following January or February. Growing citrus in our climate is always risky because of winter freezing temperatures. With most cold sensitive plants we would want to wait until after the last possible freezing event. This would put it into perhaps mid-February.

Immature fruit of Myers lemon in container

Waiting this long, even though it's the right thing to do with winter tender plants, is a problem with Myers lemon because it begins to flower so early. So we have to take our chances and prune right after harvesting in early January before flowering begins.

 

This table taken from University of California Riverside document below

Frost damage information can be found here

Myers lemon should handle temperatures down to about 20° F. The amount of damage depends on the temperature but also on the length of time the temperature remains. So 20° F just before sunrise is a lot less damaging than reaching 20° F at 3 AM and staying there until sunrise. 

Immature fruit of Myers lemon in container

The number one reason we have fruit failure in Myers lemon in our Las Vegas climate is because of late freezing weather. Even though Myers lemon can withstand temperatures close to 20° F, the flowers or young fruit cannot. They begin to bloom in January or February and may have flowers or very small fruit on the tree and a light freeze comes by and ruins the crop. Then I get emails about why my lemon tree didn't produce any fruit this past year or last two years. 

It is extremely important to put citrus in warm microclimates in Las Vegas yards and out of the wind in our winter cold climate. You will need to cover Myers lemon whenever temperatures get close to freezing, 32° F, if they have flowers or small fruit. If they do not have flowers or small fruit than they can withstand colder temperatures.

Another point worth mentioning is that cold hardiness varies during the winter depending upon the weather. During a normal winter, temperatures slowly but continually drop colder and colder until we hit our winter minimum temperatures. Temperatures stay cold during the deepest part of the winter and then minimum temperatures begin to climb as we approach spring.This past fall was nearly perfect as temperatures, generally speaking, dropped lower and lower at a very slow pace. This gradual drop in temperature was reflected in our nice fall colors which remained for about a month in November and December.

We had some nice fall color like this during November and December In Las Vegas due to the gradual drop and fall/winter temperatures

Some fall/winter/spring weather is not this nice. Sometimes we can get a sudden drop in temperatures in the fall that can catch normally cold hardy plants off guard. Then we see damage to these plants at temperatures warmer than their minimum temperature.

The reverse can happen in the spring when we have very low temperatures, followed by an unexpected early rise in minimum temperatures then followed by a sudden drop to freezing weather. This sudden drop below freezing after a warming spell can damage trees at temperatures above their minimum.

Sorry for the long winded answer but cover Myers lemon that has flowers and fruit as soon as you hear temperatures might reach freezing.

Lemon Disappearance Due to Rats

Q. We have a critter attacking our lemons. It does not eat the fruit, only the peel. It eats the peel so cleanly that only the bare fruit is left hanging on the tree. The white pith is gone to. It is a strange thing to see a naked lemon hanging on the tree. Do you have any idea what this critter could be?

Pomegranate hollowed out by rats

A. This is most likely rats. I have not seen nor has it been reported to me directly but several reports in the US and Australia attribute the eating of lemon peels but not the pulp to rats. This can happen to fruit on the tree or on the ground.

            Rats will also gnaw on the bark and branches of citrus trees.

Contrary to this, it has been reported that rats will eat the pulp of oranges and pomegranates but not the rind or outer covering. It is not understood why but lemon peels and pomegranate juice is high in Vitamin C and calcium.

Rats produce their own Vitamin C inside their bodies so it is not clear what they are going after by selectively eating rind and not the fruit. It is also reported to me that rats will eat guava fruit and papaya in the tropics, another source of high Vitamin C.

Research on rats and Vitamin C in the early 1900's report that rats may benefit from extra Vitamin C in their diets in growth and reproduction. Better get the rat traps out. 

Winter Watering Schedule for Lemon

Q. I have a Eureka lemon tree and a Rio Red grapefruit tree. Is it best to stop watering them through the winter weather or should I continue with their regular watering schedule?

Eureka lemon growing in Las Vegas Nevada while fruit still immature

A. They should have a winter watering schedule and water to them should not be turned off. Get a general idea when to water by monitoring the soil moisture with an inexpensive soil moisture meter. Purchase these at most nurseries or garden centers where they cost less than $10.

Simple moisture meter use to get a general idea of the water content of the soil

A winter watering schedule should be somewhere between 10 days and two or three weeks. Plants in containers must be watered much more often.

Push the tip of the meter as deep as you can in the soil somewhere beneath the canopy of the tree and midway between drip emitters if they are present. Do it in two or three locations. These meters are inaccurate but they give you a general idea if the soil is dry or wet. Water when they meter is midway between wet and dry.

            Trees that have leaves present use more water than trees without leaves. A layer of wood chips as a surface mulch will cause you to water less often. A lack of water or very cold weather may cause leaf drop

Apple Tree Not Dropping Leaves

Q. My apple tree is still full of leaves and hasn’t lost one yet. Should we wait to prune once it starts losing leaves or is it okay to prune in the next couple of weeks? The leaves have turned a purply brownish color but are still very much alive.

A. Go ahead and prune. We have not had a freeze hard enough to knock off the leaves. The tree is fully asleep for the winter.

Actually you can start pruning fruit trees as soon as they stop growing in late fall. We normally wait until leaf drop because we can’t see where to make the pruning cuts easily. You can also wait to prune until near February and that will be fine as well.

Leaves can be removed by running your hands down the branches if they are in reach. Try shaking the limbs or rap them lightly with a broom and they should drop as well.

If you want the leaves to drop on their own, turn off the water to the tree until leaves begin dropping and then resume your irrigations as needed.

As for me, I would just wait for normal leaf drop if it is difficult to see where to prune.

Walnut Husk Rotting with Worms

Q. Our walnut tree is at least 10 years old and producing wonderfully for the past 3 years. This year toward the end of the season, the husks started getting black. I opened one and saw little white worms. I opened the nut shell and saw no damage to the nut itself, so we did nothing. By the end of the season, most of the husks were on the ground, all black. Of the husks with nuts, the nuts were okay but there were a lot of husks with dried up black nuts. We also noticed this larger branch on the tree that seems to have split its bark.

Damage to husk of English walnut

Damage to English a walnut limb

A. This sounds like walnut husk fly damage to the husk. If walnut husk fly damage starts early enough to the husk they can cause a nut failure just like you describe. If damage to the husk is later in the summer, the nuts inside will fully develop.

Walnut husk fly adult is around the size of a housefly and lays eggs just below the surface of the husk. This blackens the outside of the green, immature husk and causes it to get soft. Eggs from walnut husk fly hatch into maggots, or worms as you call them, feeding on the inside of the husk.

After a few weeks, older maggots fall from the husk to the ground and burrow into the soil where they spend the rest of their life before emerging as adults the following summer. They emerge as very colorful, mature flies ready to repeat the cycle. This lifecycle is repeated once a year with egg laying on husk starting in mid to late summer.

            The University of California has an excellent fact sheet on the Internet concerning the walnut husk fly and located at http://www.ipm.ucdavis.edu/PMG/r881301211.html. Control measures are mentioned but a bit difficult. If there are other walnut trees in the area this could cause an increase in the population of this pest in coming years if they are left uncontrolled.

Damage to tree limb

The pictures of the tree limb you sent look like borer damage to me. The same borers that attack fruit trees such as peach also attack walnut. Pull off the loose bark from the limb and look for damage from borers on the surface of the exposed wood.

If borers damage is present, remove all of the loose bark with a sharp knife. If the damage to the limb is more than halfway around its circumference, remove the limb. If it is less than half, the tree has a good chance of recovery if all the loose bark is removed down to healthy wood.

Covering a Joshua Tree During Freezes?

Q. I transplanted a Joshua tree into our new backyard in March. It is doing great. Do I need to cover it as temperatures dip down below freezing? 

A. No, you do not need to protect it with any kind of freeze protection through the winter. They are good down to about 10F. Make sure you are watering it infrequently or it can develop root rot and die. Fertilize it once lightly in the early spring with a fruit tree or rose fertilizer.

Just a quick note on covering plants. If you are using a plant cover that does not allow much light through it, you should be taking it off during the day and replacing it whenever you think temperatures are getting too low. If you are using a frost blanket or frost protection which allows light through it, you will not need to take it off during the day. However, you should remove it as soon as danger of those freezing temperatures have passed.

Desert Horticulture Meetup Group Has Been Organized for Jan 23

I started a new Meetup Group on desert horticulture. The first meeting will be on January 23. The focus is on successful horticulture for fun, pleasure and profit in the desert. Get in on the ground floor because the direction of this group will depend on the members.

Find out more about the Desert Horticulture Meetup Group

In the first meetup we will have introductions and I will give a brief presentation about our desert environment and the problems this environment presents to us in horticulture. At the conclusion we will discuss our future plans as a Desert Horticulture meetup group.

Who: Anyone
What: Growing plants in the desert for fun, pleasure or profit
When: 9 AM, Saturday, January 23, 2016
Where: Viragrow meeting room, 1100 East Delhi St, North Las Vegas, Nevada

Brown Spines on Agave stricta

Q. A quick question about a newly planted Agave stricta. Within 2 weeks of planting the spines have begun turning brown from the tips down. Do these plants generally brown out in the cold or is this one dying? It is a 15 gal plant - purchased from a local cactus nursery. It had some brown on a few stems shen purchased, but not like this. It was planted according to the instructions from the nursery with a sand/soil mix at bottom and sand around the perimeter.

Click here to see what Agave stricta looks like

A. I had to look up that particular agave because I did not know it. There is some information about it at the San Marcos nursery website

http://www.smgrowers.com/products/plants/plantdisplay.asp?plant_id=84

It is found growing in southeastern Mexico in its native habitat at about 5000 feet from what I could find. San Marcos nursery says it will handle temperatures down to at least 20° F. This is for Agave stricta ‘Nana’ so I am wondering if this is what you have or not.

A. stricta is confused with A. striata a lot because they look almost identical. This particular cactus may benefit if it's not placed in a location where it receives very hot direct sunlight in the afternoon. It sounds like it is a little bit delicate perhaps because of where it grows and its elevation.

Click here to see what Agave striata looks like

I am thinking you may have one of two or three things going on with yours. I don't think it's temperature. If this cactus was growing in a shaded or semi shaded area and then placed into an area that receives a lot of direct sunlight in the late afternoon it's possible that it could be sun damage.

How you planted this cactus sounds fine but if you are watering it too often, even with good drainage, this could also cause problems. When water is scarce it relies on internal storage of water. During the summer I would not water it more than every three weeks if you are planning to push some growth.

If you're happy with that size, you can water it less often than that. It is also possible that the soil mix that was used could have been a little too saline. Flush the soil with several gallons of water a few times to remove any excess salts if you think this might be a problem.

But I do not think it is a temperature damage but more likely to be sun damage or damage from irrigation. During the winter you should be able to water only once or twice during the entire winter.

Further thinking, it is POSSIBLE it could be a salinity problem. There are soil mixes out there that use sands with lots of salts in them and they are not washed sands. Wash plenty of water through the soil where you planted a couple of times a few weeks apart to reduce salt problems. Now is a good time to do that because temperatures are cold and tolerance to lots of water in the soil is much higher in plants during cool or colder weather.

Acacia longifolia Tolerance to Cold in the Mojave Desert

Q. Would Acacia longifolia do okay in the Las Vegas area?

A. San Marcos Growers reports cold hardiness down to 20F so it will take temperatures similar to Myers lemon, a fairly cold hardy citrus.

Click for A. longifolia at San Marcos Growers 

It is possible it might have dieback during some extremely cold winters but it should re-sprout easily from its base once it has established for one season. Like any Acacia I worry a little bit about allergies from its pollen. It is a rather large plant usually grown as a shrub but I think you could train it into a small tree fairly easily. It should handle our soils with little problems just make sure that you amend the soil at the time of planting with compost.

Anyone with experience with this plant?

Planting Vegetables from Seed in January

I have seen garden editors right that there is very little to do in January. How wrong! This is a very busy time of the year for vegetable production. In our cold desert climate with warm days and cold nights some of the best vegetables of the year are produced. Cool and cold winter temperatures slow growth of plants which concentrates flavors and reduces bitterness in many of our cool season vegetables.

Germination from seed. As long as temperatures are warm enough during the day, seed germination of cool season vegetables may take longer but they will germinate if the soil is warm enough. Loose, dark, fluffy soils are warmer than heavy soils. Work in enough compost so that the soils are no longer compacted. Warm air during the day must be able to enter the soil through loose pores to warm it.

Select vegetable seed of known varieties that have performed well in the past or have been recommended to you by others who are good gardeners. Don’t use varieties of seed that are unknown to you unless you just want an experience and don’t care about the end result.

Know the temperature of your soil. This is important because diseases that are dormant in the soil may affect some vegetable varieties if the soil temperature is borderline for them. Beans are a good example and may fail due to root diseases if planted in soils that are too cold.

 

Use this soil temperature guide for vegetables

Prepare the area to be planted with seed with a high phosphorus fertilizer of your choice. Triple super phosphate is a good choice for conventional gardeners. Bone meal, bat guano, mushroom compost are good choices for organic gardeners.

Cover soils to be planted with clear or black plastic to warm the soil. I prefer clear plastic. Cover the soil with plastic two or three days before planting. Pin the edges of the plastic to the soil. Cover the edges of the plastic with soil so the wind does not lift the plastic. Just before planting cut slits in the plastic where seed is to be placed and leave the plastic on the soil surface until plants have germinated or longer.

Pre-germination of vegetable seed initiates seed germination. Pre-germinating the seed is wetting the seed long enough for a long enough period so the seed absorbs water. This is the first step in germination. The seed is kept in water at room temperature for 6 to 12 hours. The seed is then removed from the water and the surface dried in the air or with paper towels. The seed should be planted as soon as it is dry enough to plant.

Planting depth of seed is related to its size. Very tiny seeds are placed on the surface and covered lightly with soil. Larger seed are planted in the soil to a depth twice its diameter.

Fruit Tree Pruning Workshop in Twentynine Palms January 9

On Saturday, January 9, 2016, I will be at the Twenty-Nine Palms Inn in Twenty-Nine Palms, California, to present a fruit tree pruning workshop. I will also be discussing how to apply fertilizers and what kind and pest control operations that should be performed this time of year. The workshop will begin promptly at 9 AM. I will bring along some fertilizers for fruit trees and EDDHA iron chelates from Viragrow in Las Vegas for those interested. Contact me if you need me to bring along anything else that might not be available locally.

Fruit tree workshop presented last year at the Twentynine Palms Inn

Fan Palms Yellowing and Browning

Q. I have three mature California fan palms, aged at least twenty years, planted quite close to each other and located in Mesquite, Nevada. Two or three years ago, one showed signs of early leaf browning and soon died. Now leaves of others are quite yellow but stems and new growth at the top of the tree is green. I'm afraid they are going the same way as the one that died! Disease?

Yellowing palm leaves of the reader

A. I do not think the yellowing and scorching is directly related to disease. I think it is primarily a soil or plant nutrient problem that will not be solved simply by adding fertilizers. Irrigation might be part of the problem IF the trees are watered too often. In your particular case, I think several things may be going on at once.

I’m a big proponent of soil improvement when planting anything in our desert soils. In Mojave Desert soils, and soils brought in as fill around homes in housing developments, soil improvement at the time of planting is an absolute must even if you are planting cactus.

Desert soils are usually very low in organic matter like this soil. The light tan color of the soil is an indicator of a very low percent of organics in the soil.

If your soil is tan colored or very light brown, there is zero organic matter in that soil. Palms are typically planted without much consideration for any kind of soil improvement. They are planted in tiny holes, the roots surrounded with very little if any improved soil. Once planted, the soil surrounding the plant is covered with rock mulch.

In this type of soil environment roots suffocate and die over time. If they don’t die in the first couple of years, they have a great deal of difficulty taking up the proper nutrients from the soil even if fertilizers are applied. They become unhealthy.

The plants react to this poor soil environment by turning yellow. It’s not a disease caused by disease organisms directly but the plant color indicates they are in poor health.

To correct this problem, add organic material to the soil surrounding the roots and improve water drainage and movement of air into the soil. Until this is done, you will see very little improvement to these plants just by adding fertilizer.

In the past we used a technique called “vertical mulching”. It is no longer talked about much anymore but it was effective. Vertical mulching created vertical holes to a depth of 2 to 3 feet around the plant in the root area. These vertical holes were filled with improved soil.

Read about vertical mulching here

Vertical holes were created using a high-pressure watering device or a post hole digger. Pull back the rock mulch where you are going to create vertical holes a foot or two from the trunk. Create the holes using a post hole digger or water from a high-pressure nozzle to a depth of 2 to 3 feet. Be careful of irrigation lines.

Fill these holes with a 50-50 mixture of the soil you took out of the hole mixed with compost, minus any rocks larger than a golf ball. Create a minimum of four holes around these trees. Use these spots in the future to add fertilizer once a year. Apply more compost on the surface to further improve soil at the surface and put back the rock mulch.

Make sure plastic is not on the soil surface surrounding the plants and under any mulch. Plastic on the soil surface can create similar problems.

What To Do To Fruit Trees in January

Class in 29 Palms in 2014

What should you be doing with your fruit trees now?

• Finish your fruit tree pruning before February 1
• Fertilizing fruit trees
• Controlling pests

Thanks to Viragrow for letting me use pictures of their products.

Fruit tree pruning. I gave several classes on fruit tree pruning in December. I will be giving is in Twentynine Palms, California, on Saturday, January 9 beginning at 9 AM at the Twentynine Palms Inn. You can read about it on their blog soon or on my blog.

The major topics I covered included size control and improving fruit production. I divide fruit tree pruning into two operations for those just learning how to prune fruit trees; first of all control the size of the tree and establish its general architecture or structure and secondly prune to improve fruit production.

Fertilize fruit trees in our climate any time in January before the first week in February or before the signs of new growth if you are not in our climate. If you are late by a couple of weeks you can still do it. Use conventional fertilizers or compost. 

Use any fertilizer that is designated as a fruit tree fertilizer. In a pinch, you can substitute a rose fertilizer. Follow the label directions. 

If you were in my class, I would show you how to "read" a tree to determine how much fertilizer to apply. If you don't know, follow established guidelines that you trust. You can apply it on top of mulch or pull the mulch back and put it on top of the soil, then replacing the mulch. 

Make sure that you water it in enough to get the fertilizer in contact with wet soil. That last statement, in wet soil, is very important. Fertilizer cannot move to the roots if it is not in contact with water. 

Example of a dormant oil
available from Viragrow

Be careful how much phosphorus, the middle number, you apply. Phosphorus can hang around in soils a long time and it can build up concentrations if you aren't careful. Apply it only once during a growing season.

Controlling pests. Applying a dormant oil at least once, if not twice, during the winter is a very important preventive pest control application. It is aimed at aphids, scale insects, spider mites and a few other general pests that might appear this coming growing season. 

It is primarily aimed at "suffocating" these insects so it is important to apply it on a warm day with no wind. It is best applied by high pressure pesticide application equipment. However if you are using a backpack sprayer or other pressurized sprayer keep the pressure as high as you can during the application. This will help the oil cover as much surface as possible without leaving any gaps. 

Solo backpack sprayer

Low-pressure equipment or hose and sprayers "spit" out the oil which makes for a very uneven application and wastes a lot of the dormant oil. Dormant oils for homeowners are nearly always lightweight summer oils that are much less dangerous to plants than some of the winter oils applied in decades past.

Don't spray unless you have a problem or you had a problem last year and you're trying to get a jump ahead. 

Mature leaf footed plant bug

A prominent pest on fruit and vegetables last year was the leaf footed plant bug.Your landscape right now. Look for the adults that will be ready to lay eggs on your plants as soon as it is warm and they have some surface area. 

They will most likely hangout right now on broadleaf evergreen trees such as bottlebrush. They can see you coming and will move away from you as you approach the tree or plant. 

The adults have wings so they will be flying in from neighbors when temperatures start to warm up. Sprays that contain pyrethrin or the synthetic pyrethrins are a good choice on these critters. 

As a last resort, Sevin insecticide will control them but use that conventional insecticide when you have exhausted other possibilities such as oils, soap sprays and pyrethrin products.

I have a lot more information but you have to start asking questions if you want it.

Be Careful of Wildflower Seed in Primitive Areas

Q. Our family owns an unimproved lot at about 8500 feet in southern Utah. A combination of heavy snowfall, strong winds and disease resulted in blow down of dead and live trees. We are planning to clear the area to reduce the potential of fire and then seed native plants and wildflowers seeds. I cannot find any appropriate seed available to do this.

A. There are seed packets available locally and online labeled as wildflowers. But these are generic wildflowers and not all native to our area. You are right to be looking for seed appropriate to your area. Generic types of wildflower seeds should not be used for seeding near semi-primitive or primitive areas.

Introducing plants that are not native will result in future problems. Some non-native plants can invade undeveloped areas and “choke out” native plants. This results in multiple, successive future problems for other plants and animals relying on native plants.

Check out this document online from the Utah Native Plant Society regarding sources for native seeds. http://www.unps.org/index.html?PAGES/cohortlist.html. Also download the document from the University of Nevada titled “Living with Fire” which aims at reducing the fire potential for homes located. In the Lake Tahoe area of Northern Nevada but has information appropriate to your situation. https://www.unce.unr.edu/publications/files/nr/2006/SP0611.pdf

Talk with your local Forest Ranger and decide which of these seed choices would be appropriate for your location. If you have trouble downloading these documents, contact me and I can help you.

When you are ready to seed, seed right into the snow as it is disappearing in the spring. The water and warming soils will help the seeds to germinate.S

Does Newtown Pippin Apple Produce Good Flavor in the Desert?

Q. How has the Yellow Newtown Pippin apple performed in our climate. I would love to have one if the quality is good here.

A. I published a list of recommended fruit varieties for our climate and made available on my blog. These are fruit tree varieties I have evaluated over a minimum of five years of fruit production. It can be misleading to recommend a variety when it has produced for only one or two seasons. http://xtremehorticulture.blogspot.com/2011/10/recommended-fruit-trees-for-southern.html

I am not concerned so much whether this variety of apple tree will grow here or not. It will. My main concern is the quality of the fruit it produces in our climate and soils. Just because you like Macintosh apple you purchased from a local grocery store does not mean that a Macintosh apple grown here will taste the same. There are numerous potential problems with a Newtown apple grown in the desert. Only time will tell.

Yellow Newtown Pippin has not had a long enough performance history in our climate to recommend it for the general public. It ripens a little bit before Granny Smith and a month or so before Pink Lady and this is a good time for apples to ripen in our climate. However, other influences such as our soils and climate while it was growing will impact its quality.

Download a copy of my recommended fruit tree list

Extra reading about the Newtown Pippin and Yellow Newtown Pippin apples

https://www.slowfoodusa.org/ark-item/newtown-pippin-apple

http://www.orangepippin.com/apples/newtown-pippin

http://www.nytimes.com/2003/11/05/dining/it-s-crunch-time-for-the-venerable-pippin.html?pagewanted=all

Firewood and Pine Trees. A New Deadly Combination in Southern Nevada?

The following is a Release from the U.S. Forest Service and Nevada Division of Forestry regarding a new pest found in firewood in southern Nevada. This pest will leave the firewood and may attack pine trees in southern Nevada, in particular Mondale and Aleppo pines. From the sound of it, infested firewood was brought in from California into southern Nevada. If you think you have purchased some of this wood please contact the Nevada Division of Forestry for more information about what to do.

Goto Nevada Division of Forestry Contact Information in Las Vegas

Goto Mediterranean Pine Engraver Information from USFS

I was alerted by Jeff Knight from NDA that the Mediterranean pine engraver, Orthotomicus erosus (Wollaston), has been positively identified from two locations in southern Nevada. One site was near Blue Diamond and the other was a firewood distributor in Las Vegas.  The identification was confirmed by Jim LaBonte of the Oregon Dept. of Agriculture.  The beetles were trapped in Lindgren funnels with ethanol and alpha pinene as lures.  This represents the first record of this beetle in the U.S. outside of California.  The beetle appears to very aggressively attack stressed trees and rarely attack healthy trees.  The suspected host near Blue diamond is Pinus monophylla, no suspect in for the Las Vegas site yet.  Attached is the USFS Pest Alert for the beetle.  Further investigation of these sites will take place in early Jan. to determine possible hosts and entrance into Nevada. At this time NDA will not pursue any regulatory/quarantine actions, but will be working on educational information on the insect.

More information about the Mediterranean Pine engraver beetle

Freeze Protection Using White Breathable Fabric

Q. We use a white, breathable fabric for some of our tender desert plants when there's a chance of freezing temperatures.  We're at a 3000 foot elevation on the eastern slope of the Spring Mountain Range and temperatures can be 8° F more or less than those reported at McCarren International Airport. We go by the plant description temperatures and for 30 degree forecasts we cover those that could be damaged down to 20 F degrees. Can the fabric be left on continuously for long periods of time even though nighttime temps are higher than 32 degrees if it's anticipated that in a week or two or more temperatures will drop again below freezing?  Some folks who sell this product say it can be left on all winter but I thought I had better check with you.

Row crop cover used for cold protection for vegetable row crops 

A. Yes you can leave it on! This is a major advantage with these types of products specifically made for protecting plants from light freezes. They are called by several different names including crop covers, floating row covers, frost blankets and floating row crop covers.

Some background on these products will help you understand them. These covers are flexible, nearly transparent, extremely lightweight and made from fabrics that are typically spun or woven.

They “breathe” allowing light, rain and air movement through them but still capture heat coming from the ground. They transmit so much light that there shading effect on plants is only somewhere around 15 to 20%.

They gained fame primarily in commercial vegetable production about 30 years ago for two distinct reasons; protection of vegetables from light frosts and earlier production. When left on permanently during cool weather, they can raise air temperatures under the fabric about 5 to 6° F which causes vegetables to grow faster which in turn means they can be harvested earlier.

Besides protecting young tender plants from freezing temperatures and growing faster, they also provide another valuable advantage; insect protection. In organic production they are a valuable asset to leafy greens that can be damaged from wind, intense sunlight or chewing insects.

            Row crop covers are placed over new seedlings or transplants and kept from blowing away with metal staples and a soil covering the edges. They are also used as a covering for low tunnels used in vegetable production. 

Landscape Committee Wants Evergreen Shade Trees

Q. I am on our landscape committee for A Henderson HOA. We are going to remove many dead and diseases trees in our small community. Mostly privets that through the years have died after we converted to desert landscape from grass. Others are mainly ash trees that are diseased and or have dead limbs and with pruning look terrible. Most of our yards face either East or West. We have been advised to replace the trees with fruitless olives or living oak. All yards are small and have rock mulch. As many other communities we are cash poor and need to make a wise decision because it will be expensive. We are looking for evergreen, shade trees if possible.

I forwarded this question to Andrea Meckley, a Certified Horticulturist working in the Las Vegas area since 1992.

A.  I understand your situation with the privet trees doing poorly.  Since you are going through the expense of replacement I realize you want to make good choices.  Below are a few thoughts:

1. Fruitless Olives:

                  Pros:  evergreen, little leave drop 

                 Cons:  slow grower, sometimes they will fruit even though they are not supposed to.  If this happens you can apply a solution to stop them from fruiting if it concerns you

2.  Southern Live Oak: 

                 Pros:   evergreen

                 Cons:  slow grower, debris from leaves and acorns

Between the two above I would choose the Olive. 

 Young European olive

Young Live Oak

Since you have existing sycamore and desert willow trees that are deciduous, I would also consider the following medium size evergreen and semi-evergreen trees:  Xylosma tree (Xylosma congestum), Holly Oak (Quertcus ilex), Blue Palo Verde (Parkinsonia florida), Desert Museum Palo Verde (Parkinsonia 'Desert Museum'), Bay Laurel standard trunk tree (Laurus nobilis), and Shoestring Acacia (Acacia stenophylla) which may be a little messy. 

Palo Verde in Bloom

Young shoestring Acacia

One good source for good pictures and more information can be seen at Southern Nevada Water Authority website.  Please contact me if you wish to discuss further.

Andrea Meckley

Certified Horticulturist

American Society for Horticultural Science

imn2plants@aol.com