What? No apricot fruit?

Q. I have Katy and Blenheim apricots that are supposed to be low chill and self-pollinating but they barely produced any fruit the last two years. Three years ago both trees had a large amount of fruit. The trees seem to be healthy and there were plenty of bees.

A. Both of these types of apricots are older varieties and excellent producers in our climate. They are both self-pollinating and do not require much winter chilling temperatures to produce fruit.

Fruits of Katy apricot great for drying

You didn’t tell me if you saw flowers or not. The presence of flowers and no fruit is a big clue as to what may have happened. I am guessing you had lots of flowers but no fruit.

My guess is it was due to freezing temperatures during February. Apricots will flower during the first couple weeks of February. Last year there was a late freeze that could have eliminated apricot fruits in parts of the Valley where cold temperatures accumulate.

Apricot fruiting spurs

When fruit trees are near flowering, in flower or they have set small fruit, then these fruit buds/flowers/small fruit will tolerate temperatures from 32 to about 30° F. Nothing lower than this.

Too much shade from neighboring trees can eliminate fruit production in all but the sunny locations of the tree, usually hear the top or exposed sides.

You didn't mention pruning. If anyone pruned these trees and removed small side shoots from branches then there will be no fruit. Fruiting spurs are small side shoots going from branches. Fruiting spurs are needed on apricot for fruit production.

So unless someone pruned out the fruiting spurs or there was a late freeze this year, you should have plenty of apricots.

Ash Roots Can Be Removed with Care

Q. I have a 15-year-old ash tree in my backyard and roots are pushing up the brick walkway. Would it hurt the tree if I took up the brick and cut the roots off before they grow under the brick? The walkway is about six feet from the tree.

A. It shouldn't be a problem that far from the tree but let me tell you how I make that determination.

I look at where water is being applied to the tree. Tree roots will grow toward water. They will grow more aggressively where there is more water and fertilizer. They grow less aggressively in and toward dry areas.

Roots of fan tex ash

At a distance of 6 feet away from the trunk there should be no problem at all unless it is getting all of its water mostly from the area where roots are being cut. If tree roots are getting water from multiple locations then there should be no problem at all if you remove these roots.

Roots of ash surfacing in a lawn

Cut the roots in that area which are growing to a depth of 12 inches. After cutting them, sanitize the cut ends of any large roots that have been cut with soap and water. Let the cut ends of the roots dry and heal for a couple of days before putting soil back around them. There are some plant diseases present in soils that can enter the tree through open wounds. Sanitizing the cut ends and letting them heal first helps prevent these diseases from entering the tree.

Backfilling around the cut ends of roots while cuts are still fresh can increase the likelihood of disease problems.

Brown Center of Pampas Grass Common

Q. A few weeks ago I cut my ornamental pampas grass down, removing all last year’s dead growth. As the new growth is starting, I noticed a peculiar brown, circular pattern in the center that hasn't happened in the past. The new growth is coming along fine; nice and green, and a couple inches taller. Just nothing in the center.

Brown Center of pruned pampas grass

A. This brown center is common to many ornamental grasses as they get older. When the plant is very young and juvenile the entire plant is green, even the center.

As these plants get larger, they grow from outside shoots, or tillers, that make the plant larger in diameter. Each year this clump of grass gets larger and larger with the brown interior getting larger as well.

When these ornamental grasses get larger, the entire clump is dug up and divided into several smaller clumps. This propagation technique is called “division”. The brown portion of the plant is removed and the smaller plants are replanted or containerized and sold as a juvenile plants.

However, the new growth of your plant will cover up the dead interior and I don't think you will notice it anymore until you cut back again. 

Whitewash Not Meant for Stopping Rabbits

Q. I planted a couple of fruit trees and a visitor started chewing on it a bit, possibly a baby rabbit.  What should I treat it with or should I just paint it now with whitewash such as a 50/50 mixture of latex paint and water? I read this mixture stops rabbits from chewing on them.

A. I would strongly suggest you protect these trees from rabbits by putting a 2 foot tall cylinder of 1 inch hexagonal chicken wire around the outside of the tree. This excludes rabbits from chewing on the trunks.

A cylinder of 1 inch hexagon all chicken wire surrounding a new fruit tree to protect it from rabbit damage

Once the trunks get about 3 inches in diameter rabbits will no longer bother them and it can be removed. Be sure to bury the bottom edge of this cylinder one or 2 inches into the soil.

I don’t know if whitewash will prevent rabbit damage. The major reason for applying whitewash is to help prevent sunburn to the trunk and limbs of young, and even older fruit trees susceptible to sunburn. Fruit trees particularly susceptible are peach and nectarine.

Whitewashing the trunk and large limbs of an older fruit tree

 Whitewash years ago was made from a mixture of lime and water. Now most commercial whitewash is made from diluted white latex paint. I recently purchased some commercial, ready to use whitewash and I still found it needed more diluting with water.

You want a mixture of water and latex paint that changes the color of the bark from brown to a very light color. This better reflects sunlight and reduces damage from sunburn.

I have never heard of it used to deter rabbits so in my opinion it is strictly folklore unless it can be validated by others. There is a lot of anecdotal information floating around out there that is not very accurate but simply passed on without any proof.

Spraying Oil on New Fruit Trees Not a Bad Idea

Q. Should you spray fruit trees with horticultural oil if you are planting them for the first time?

New bare root fruit tree ready for planting

A. Horticultural oils are made from refined mineral oil and used during cooler times of the year to smother insects that might cause problems to a number of different plants. Even though horticultural oils are “natural” they are considered an insecticide since they kill insects by “smothering” them. They are most effective on aphids, scale insects, whiteflies and spider mites.

Horticultural oils are indiscriminate killers of insects, similar in that regard to soaps used as insecticides. They are indiscriminate because they kill any insect, bad or good, that is sprayed. But these types of sprays are safer to apply and for the environment than most conventional insecticides.

Aphids causing leaf curling and stickiness on Plum

No, you don't need to spray newly planted trees with horticultural oil when planting them unless you think they were infested when you bought them. However, it is not a bad idea and probably a good safety precaution since these trees are coming from places where there are usually a lot of new insects that can be brought into your garden.

Heavenly Bamboo/Nandina Yellowing and What to Do

Q. I noticed all my Nandinas, also called heavenly bamboo, are turning bright yellow. Is this a fungal disease problem? I'm worried that whatever this is will spread to all the other plants.

A. No, it is not caused by a disease organism. This is severe iron chlorosis and fairly common to heavenly bamboo growing in alkaline and desert soils.

Leaf yellowing happens frequently because of a lack in organic matter in the soil, increasing alkalinity or soil pH. I see heavenly bamboo planted with rock mulch and this yellowing frequently becomes a problem in a few years after planting in these situations.

Heavenly bamboo and rock mulch and yellowing

Start a program of soil enrichment and add a good quality iron product to the soil now as new growth is appearing. If there is rock mulch present, remember this type of mulch is probably adding to the problem. Plants like Nandina do not like rock mulch but grow healthier in a wood mulch environment.

Personally, I prefer iron EDDHA chelate as the source of iron to apply to the soil. It is a dry powder and must be watered into the soil accompanied by a good quality fertilizer.

Iron does not move from the soil into leaves that are already yellow. Iron applied to the soil only affects new growth and new leaves. The only way to improve the green color of existing yellow foliage is to apply iron fertilizers as a foliar spray.

Use any of the iron foliar fertilizers (liquids or powders that are mixed with water to make a liquid) and sprayed on the leaves. Sometimes it can take three or four applications, a week apart, to get them to green up adequately. Some plants green up with a single application.

The water used when spraying liquid iron should be distilled water. If using tap water, adjust the pH of the water to 7.0. When making applications to leaves always use a wetting agent such as EZ Wet.

You can also improve the new foliage to dark green by pruning them back, close to the ground, and letting them regrow after you apply iron EDDHA, compost, water and a fertilizer.

Desert Spoon For Desert Landscaping

Queen Palm Not A Good Choice in Desert Climates and Soils

Q. Our backyard is in full sun, gets very windy, and has very poor soil. We are landscaping around a new pool and would like a tropical look. We would love to put in a queen palm but we read they may not do well here. Any suggestions for a different palm like Kentia or Foxtail?

A. The queen palm won’t work in your situation. It does not like poor soils, heat, lack of humidity and wind. It is not a good choice for our hot desert climate in general.

Queen palm tends to look "ratty" in our desert climate and soils.

Be careful planting palms near a pool. Most people do not like the seeds dropping and the mess it makes.

The only palm which stays small and hearty for our area is the windmill palm. The pygmy date palm is a possibility but it is sensitive to our winter temperatures and may suffer from winter freezing. The Mediterranean fan palm stays short but can get quite large in diameter. Both Kentia and Foxtail palms are not meant for our climate.

Kentia palm is considered a "tropical" palm and intended for interior use in desert climates.

There are plenty of plants that give a tropical look to a landscape that are desert adapted and tolerant of our soils. Mesquite, desert bird of paradise, flax, ornamental grasses, canna lilies, rose of Sharon, crape myrtle, Gold dust plant (shade), papyrus, nandina, mock orange, cats claw vine, can be used to mention a few.

Tropical looking landscapes should be densely planted and designated as a high water use area. Use compost and wood chip surface mulches that won’t blow easily to improve our soils and their growth. 

Citrus Seldom Needs Fruit Thinning

Q. We have a two-foot tall, two-year old Meyer's lemon with 40-50 young blossoms.  Shouldn't some clusters be thinned and if so how?

Lemon tree planted with mulch. Keep the mulch away from the trunk for the first couple of years.

A. Don’t thin them. In most cases citrus does not need to be thinned. The plant will drop the fruit it cannot support.

It is not like a peach, apple, plum where small fruit must be removed to make way for larger fruit. Just let it be and see how well is sets this year. My guess is that it will drop most of the blossoms or fruit that it cannot support. It may drop all of them if the tree is too young to support fruit growth and branch growth at the same time.

Lemon with a good fruit set

            That being said, sometimes citrus does have too much fruit on a limb. Leaving too much fruit on a limb can break the limb. If the fruit is closer than the diameter of a large fruit, start removing some when they are the size of a quarter. 

Leaf Browning Due to Insecticide

Q. I am hoping you can advise me on how to save my rose bushes I planted last spring. I sprayed my them accidentally with a concentrated insecticide, not diluted. The next morning the leaves looked like wilted spinach and I cried. Will the bushes die?  A friend told me I should have applied it to the soil.

Rose leaf scorch and death due to concentrated insecticide application. They will grow back.

A. They will come back. You burned the leaves with the concentrated insecticide. You should see new leaves and growth popping out in a week or so. During this time be careful not to overwater. Water them normally or even less often if they do not have leaves.

Always follow the label directions when applying and don’t listen to friends. Application depends on the insecticide. Some insecticides are root systemic and applied on the soil around the roots and watered in. Others are foliar and applied to the leaves.

You do not know which is which unless you read the label. The label will tell you how to apply it, when to apply and the application rate.

Multiple Trees Together Better Choice Than Multi-Budded Trees

Q. I lost two fruit trees this winter because of an irrigation problem. I would like to replace them with 4-in-1 pluot and plum tree. I’m hoping it’s not too late to plant.

Two-in-one hole fruit trees...one Santa Rosa plum and pluot by reader. 

A. It is not too late to plant fruit trees in containers but it is too late to plant them bare root or sold in packages.

I am not a big fan of fruit trees that have more than one variety on the same tree. In a few years the more aggressive varieties dominate and kill the weaker varieties. In a very short time the tree is dominated by one or two varieties instead of four.

I prefer separate trees planted very close to each other and managed as one tree. I would plant these trees about 12 to 18 inches apart; one on the east side of a large hole and the other on the west.

In the case of pluots and plum, the plum tree should be a Santa Rosa which is a good pollinator for pluots. Pluots are self-pollinating in our climate but having a Santa Rosa plum tree close may help with fruit set and increase yield.

Two rules should be followed when planting trees close together; never let them grow back into each other and keep them both pruned and trained to the same size.

What Causes Holes in Cactus?

Q. My neighbor has a cactus that has these holes on one side. I am hoping you can tell us what is causing this and if this plant is doomed to die.

A. Nothing substantial came to me regarding the holes in your cactus. Generally speaking, these holes can occur from overwatering. They can also be from a disease problem if the humidity has been high or there has been rain.

My first suspicion was a bacterial disease that causes holes in some cacti but I don't think that is the case with yours. Usually this would occur during wet or humid weather. Not if the plant has been dry.

The only thing I can tell you to do is be careful how often you water. Make sure the plant has good drainage. If the hole does not have any soft tissue around it just consider it a temporary thing and not get too excited about it. If the tissue around the hole is hard and not soft then it is most likely not getting any worse.

Here is a link to a publication from the University of Arizona on diseases of cacti and succulents

What to Use When Amending Raised Beds

Q. What should I use to amend raised beds? Mine need to be rejuvenated. Sulfur, rock dust, chicken manure, worm castings, I am not sure which ones to use or to use them all!

Raised beds are probably the best alternative when you are faced with using "fill" that was put in by the developer or builder of the home.

A. There is a lot of hype on the Internet regarding soil amendments. I can understand why it’s confusing. Sulfur, rock dust, coconut coir, worm castings, chicken manure all make promises of miracles.

Stay with the basics if you are just starting out. Amend your soils with compost each year, and your raised bed will be productive every year. The best quality compost is rich in nutrients, consistently black or dark brown in color and a pleasing aroma. Composts that deviate from these characteristics are poorer in quality.

Compost made in Amargosa, Nevada, by a dairy operation using the "windrow" method.

Composts work best if they are mixed with soil.... even desert soil. Many of the subdivisions have extremely poor soils because “fill” was used around the homes rather than soil. In many cases, raised beds filled with soil mixes is the least expensive option to having a garden.

Perlite is one of those amendments used as a soil amendment. It is used mostly for propagation and interior plants.

If compost is applied to these soils every year most of these amendments are usually not needed. Adding compost and growing a productive garden helps to lower its the soil pH so sulfur is usually not needed.

Compost added to the vegetable plots every year at the University Orchard in North Las Vegas

Over a year ago I tested three different rock dusts in several locations around Las Vegas and found no benefit to these additions as long as the garden soil was amended with compost.

The type of compost, whether it is traditional compost or compost made from worms, is up to you and your personal preference. Certainly, if you sleep better at night by adding these amendments to your raised beds by all means apply them. They will not hurt anything as long as you don’t apply too much.

Red wigglers used in worm composting...vermiculture...in a plastic bin and food scraps

Virtually all of the animal manures are effective if they are composted correctly. The only additions I would suggest when first starting off with raised beds are inocula for legumes such as beans and peas.

The type of fertilizers to use are your personal preference but organic fertilizers typically add more to the soil than conventional fertilizers but cost more. However, if your soil is amended properly at the beginning of the season then small amounts of conventional fertilizers would benefit the plants. 

Oleanders as Small Trees

 I read with interest your article in the Review Journal regarding turning Oleanders from bushes, into trees.

I have been attempting to do this with my Oleanders for the last year or two and they appear to be doing quite well. I am glad that I have been doing most of the things that you recommended in your article.

I have attached a couple of photos and hoped you would give me your opinion of whether they will continue to do well, or if I should be doing more to them.

The photographs were taken in February when it was still rather cool, but now they are starting to bloom.

Thank you for all the help you give us amateurs with our plants, trees and gardens etc. I’m sure we all appreciate it, Mr. Morris.

Reply:

Great job, Bill. The only thing I would recommend is to try and get the canopy to occupy about 2/3 of the tree and the trunks 1/3. It is more pleasing to look at. It might be a bit difficult to do that with your limited space but they look nice and make a nice small tree with flowers and is evergreen.

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Plant Recommendations Colorful, Fragrant, Heat Tolerant

Q. I am fairly new to the Las Vegas area and have a 23' x 3' area on the south side by a cement wall that gets some shade. I'd like to plant some type of bushes that are colorful, fragrant, heat and drought tolerant, need minimal upkeep and will grow approximately 6-8'. I have enough oleander.  Any suggestions?

A. I will assume from your email you want plants that stay about 3' wide, low maintenance, evergreen, and will accept some sun.  Flowers and fragrance would be preferred.  I see you want 6-8' tall   The plants listed below all stay around 3' wide.

These are all medium water use plants that grow about 3' x 3':

Dwarf Bottlebrush Callistemon 'Nana'

Dwarf Youpon Holly Ilex vomitoria 'Nana'

Gulf Stream or Moon Bay Nandina Nandina 'Gulf stream' or Nandina 'Moon Bay'

Box-Leaf Euonymus Euonymus microphylla

Low water use plants that grow about 3' x 3':

Blue Texas Ranger Leucopyllum zygopyllum

Brittlebush Encilia (2 varities available)

Autumn Sage Salvia greggii

Taller growing plants to consider with some trimming to stay 3' wide:

Heavenly Bamboo Nandina domestica

Dwarf Xylosma Xylosma c. 'Compacta'

Baja Fairy Duster Calliandra californica (deciduous)

Classic Myrtle Myrtle communis

A good source for plant information is snwa.com under 'landscapes' and then 'plant search'.   You could look up plants above and decide which are best for you.

Hope this helps.  Get back to me with any further comments or concerns.

Andrea Meckley, CH

Bugs are on the Attack; Fruit Trees and Vegetables

Many questions sent to me right now are about bugs appearing on fruit trees and vegetables. Remember, never apply sprays of any sort while fruit trees are blooming. My first recommendations for pest control are natural or organic spray remedies. If my recommendations are not natural or organic, I will tell you they are conventional spray remedies.

Yes, it will cost you more money but always use a wetting agent combined with any sprays used for controlling insects, diseases and weeds. A wetting agent is not needed when applying insecticidal soap sprays. Soap sprays can be combined with other insecticides and act as a substitute for a wetting agent.

Insecticidal soap commercial size

            Big problems right now are aphids on all fruit trees as well is young vegetable transplants. Aphids inhabit the undersides of leaves where it is darker and less obvious to their predators. Aphids are now feeding, colonizing and building their populations exponentially. They are sucking plant juices from the leaves and excreting a sweet, sticky substance called honeydew.

Apricot leaves with aphid honeydew

            Soon aphids will attract ants that collect this honeydew. Ants then climb the tree in long, continuous rows that go back and forth from the aphids to their nest which is usually in the ground. Many people will try to control the ants but ignore the aphids. To control ants, control the aphids.

Aphids and ants together with aphids only there due to the presence of aphids

Soap and water sprays are very effective if sprayed directly on the aphids. Please use either a commercial insecticidal soap or an unscented liquid detergent that contains no hand care products. I prefer a liquid Castile soap for insect control but it can be more expensive than purchasing and insecticidal soap. Some people use Dr. Bonners.

Aphids and ants on the same apricot leaves

Horticultural oils are also effective and can be safely used after bloom and until temperatures reach about 85° F. Horticultural oils are refined mineral oils. Neem oil is an oil spray and can be used as a substitute for horticultural oils if you choose.

Horticultural oil commercial size

If you have nectarine, Western flower thrips are likely attacking the fruit right now. They have been attacking the flowers even before they were open. These tiny winged insects are poor flyers but able to go the short distances between fruit and attack them, ripping at the skin of the fruit causing it to “bleed” sap which they use as food. The ripping of the skin causes it to scab, become deformed and ugly. Western flower thrips are responsible for the ugly, deformed appearance of nectarine fruit.

Thrips damage to immature apricot

Spray the fruit now with an insecticide containing Spinosad listed in the ingredients. Direct your sprays primarily at the fruit because that’s what you are protecting.

One spray application of Spinosad is not be enough to protect the fruit from scarring. You must spray it multiple times as the fruit is developing if you want it unscarred. Alternate Spinosad sprays with soap and oil sprays weekly.

Mulch Can Create Problems for Peach Trees

Q. I bought a Babcock peach in the summer of 2014 and planted it at about an elevation of 3700 feet. I planted it as you recommended including a 4 inch layer of mulch on top of the soil around the tree. The tree budded nicely but I noticed most stem ends just died and dried up this past winter.

Two-year-old Babcock peach

Dieback on Babcock peach stems from a lack of water

A. When stems die back like you describe it is usually a problem with water or freezing temperatures. Unless temperatures dropped down to 15° F it is most likely water related.

            Water related can mean either too much or too little water because both can result in stems dying back. It is obvious that a lack of water can cause something like this but less obvious if it is from too much applied water .

            Giving a plant too much water can mean either two things; either applying too much water each time you irrigate or giving the plant water too frequently. The first one, applying too much water each time you irrigate, usually doesn’t create a problem for the plant, it just wastes water. But the second one, watering too often, can be far more dangerous to a plant.

Collar rot or crown rot on honeysuckle because of wet mulch in contact with the stems

            Watering too often can fill the soil around the roots with so much water that the roots cannot “breathe” and they begin to suffocate. Allowing the water enough time to drain from around the roots allows air to enter the soil again and roots can breathe.

            Unless a plant is growing in pure sand or in a small container, withholding water for a few days before the next irrigation gives roots a chance to “breathe” again. There is enough water left in the soil to last a few days after an irrigation in normal soils.

Apple growing in wet soils with collar rot

            There is another possibility. You mentioned you have a 4 inch layer of mulch on top of the soil surrounding the tree. This will really help your trees, however do not allow this mulch to rest against the trunk of new trees. Always keep mulch away from the trunk of trees while they are young. At least 12 inches.

Wet mulch can “rot” the trunk where it is in contact with the wet mulch. This “rot” is a disease called collar rot. Collar rot disease will “choke” the trunk and prevent water from moving from the roots to the top of the tree. The symptoms are identical to a lack of water and this is a strong possibility in your case.

After Agave Blooms It Will Die

Q. I bought this plant 4 years ago and was told it is an Octopus agave. I was advised it might take 40 to 50 years to bloom and afterwards the plant will die. The stalk coming from the center of the plant grew to about 12 feet in 2 weeks. I really do not know what I am looking at or what to do.

A. This is not Octopus agave. Compare it to pictures of Octopus agave on the Internet. Yes, that is a bloom spike. The plant will die after it flowers.

The mother plant should have small offsets or pups at the base of the plant prior to blooming. You may not see them until after the mother plant dies and is removed. These pups can be replanted in new locations or given away to friends.

Pups growing at the base of American agave.

When planting agaves and cacti, amend the soil with compost at the time of planting and mixed with the backfill around the roots. They will grow better.

Be careful how frequently the plant is watered. Do not water them more often than every three weeks but give them 5 to 10 gallons when you do.

Some information on Octopus agave from Master Gardeners at the University of Arizona

Agaves look better when they are either planted in groupings of three or five with enough distance between them so they can spread out or planted singularly as a focal point in the landscape.

When planting in groups, use odd numbers of plants and plant them at different distances apart to make them more appealing to the eye.