Ash Tree Dying....Again

Q.   I have an ash tree that is 18 years old. This year about 20 percent of the tree has dead branches while the rest looks good. We really do not want this shade tree to die.

I have posted before on possible Ash Decline

https://xtremehorticulture.blogspot.com/2018/01/dieback-of-mature-fan-tex-ash.html

https://xtremehorticulture.blogspot.com/2017/10/limbs-dying-in-20-year-old-arizona-ash.html

https://xtremehorticulture.blogspot.com/2015/06/ash-dieback-or-ash-decline-they-both.html

A. That tree occupies a very important part of the landscape, I am sure. However, your ash tree may have an incurable disease called Ash Decline. In California they call it “Ash Dieback”. This disease, so far, is found only on ash trees, causes branches to slowly die in the canopy over several years. So lucky you! You can see this disease in many ash trees in the Las Vegas Valley.  But these dieback symptoms are similar to drought.

Because this ash is growing in a lawn and probably getting enough water then this dieback is suspicious. This might be ash decline. Deep water it once a week for three or four weeks and find out.

Deep Water and See if it Grows Better

            Before giving up on it, try applying more water to the base of it in a larger area. Along with its normal water application, do this once a week with a hose and sprinkler and see if that helps reduce the problem. I use a mechanical water timer that costs about $12. I adjust the water delivery from the sprinkler to about the same size as the tree canopy and water for one hour. The water should wet the soil 18 – 24 inches deep when you water. Do this weekly for one to two months. If the tree starts growing more than you must apply more water to the tree. 

Most ash trees are "mesic" and not "xeric" which means they should be given enough water when planted in a desert landscape. As any plant will, they will take water where they can get it. Are there enough drip emitters providing water to this tree? Even if you count the plants watered nearby? Maybe when its small but not when it gets bigger.

If the tree does not respond with new growth, it probably has ash decline. Remove the tree. Applying a fertilizer once a year just before new growth is enough for trees. This would be February in the Mojave Desert.

Note: I am no longer answering ash branch dieback questions here. I posted a page to it in my blog. I will respond to queries to me in an email but not post an answer.

Avocados are for Advanced Gardeners in the Desert

Q. We would like to plant fruit trees but don’t have much gardening experience. Can we plant during the summer months? Are there types of fruit with a tougher skin so birds can’t get them? My wife loves avocados, so is that a possibility for someone without a green thumb here?

Avocados come in all shapes and many different colors. These avocados were from Zimbabwe where it is warmer than Las Vegas. Las Vegas and the Mojave Desert is a bit cold for avocados so pick a variety that stays small and known for winter cold tolerance.

A. I would not plant anything but palm trees, Bermudagrass, cacti and succulents from May through mid-September. Even good gardeners prefer not to plant during the hot summer months if they have a choice. Nurseries are pretty dead compared to spring.

Good Gardeners Plant in Spring and Fall

            Why? Anything you plant now is slow recovering from planting because of the late planting date, heat, and low humidity. If you see something you just can’t say “No” to, then buy it, put it in the shade and plant it as soon as possible. Plant in the morning when temperatures are cooler. After removing it from the container, transfer it to a wet, prepared planting hole as quickly as possible. Have a hose ready and plant everything wet, wet, wet.

Plant in the spring and fall. fall months it is harder to find fruit trees you want but patience is good.

Start Slow with Fruit Trees and Avoid Birds, Don't Fight With Them

            If you are new to gardening and fruit trees, start with a single fruit tree. Purchase a 5-gallon container tree or larger. Apricot is a good choice and harvest the fruit when they start turning a color and you see the first signs of a bird nibbles.

This is a fresh bird peck in peach. Harvesting the fruit a bit earlier would forgo most bird damage when birds are not interested in your fruit yet.

            You have 2 to 3 weeks to harvest everything from the tree so don’t take it all at once! Fruit will ripen first in the hottest part of the tree and work toward the coolest. So pick the fruit first that is farthest along. Picked fruit will ripen on your kitchen counter (or garage, or back patio and covered so the birds can’t get them) and still taste the same. The fruit doesn’t need light anymore to ripen and taste good. Apricots don’t have to be soft on the tree (which by the way is a little later than when birds first start pecking them) to be “tree ripened”.

Avocado is 'Advanced Gardening' in the Desert

            Don’t start with an avocado tree unless you are an experienced gardener. I am not going to get into the “why” here, but I will guarantee you failure if you don’t know what you’re doing. Search my blog for answers. Apricot or plum is much easier to grow here than avocado.

Rose Bush Calendar of Maintenance in the Desert

Q. I planted a rose bush facing south as a memorial for my Dad and I want to know how to help it along. It has holes in some of its leaves and a few yellow leaves. I saw one grub and I got some stuff to get rid of grubs. 

A. Roses in a southern exposure have not had many problems provided they stay healthy. 

Select a Good Variety First-Off

Varieties of roses suited for desert environments handle hot locations well and may bloom throughout the entire winter if planted in the right microclimate. Like all roses, they don’t flower well during the heat which may start a month early (May) in southern exposure is like yours. List of desert roses.

Aphids heavily feed on roses in the spring during cool weather before the flowers open. They start early and are aided in their transport from rose to rose by ants.

Look at Your Rose Often

            Look at the color of the leaves and the quality of its new growth to judge its general health. New growth should be vigorous and the leaves dark green. These are two signs the plant is healthy and growing. Hopefully, you amended the soil at planting, then use organic mulch on the surface of the soil surrounding them, fertilize them three times a year and water when they need it to keep them healthy.

Even though leaf cutter bees damage rose leaves and petals, I like them. You can encourage leaf cutters with 1/4 to 3/8 inch holes drilled in 4x4's. The females use the holes for laying eggs. They are solitary bees, not social bees like honeybees so they don't need a hive.

Disease and Insects

            In dry environments like ours, roses have few disease problems and insect problems are rare, mostly occurring in the spring. We may see aphids and flower thrips in the spring and occasionally cane borer but it’s nothing to be alarmed about. You will handle these problems when you see them. Grubs feeding on the roots in the spring may occur and a systemic insecticide drench applied around the roots once a year will take care of them, and aphids, at the same time.

This isnt rose but it doesn't matter with leaf cutter damage. They always make the same size and shape holes in soft leaves and flower petals.

            The size, shape, and position of holes in the leaves tell you a lot about which insect may be causing this. Most commonly it is leaf cutter bees. We may see the same damage on vegetables, basil, and other plants with soft, tender leaves. The strategy is the same. We leave these insects alone. They are good pollinators and so we choose to live with that kind of plant damage and understand its meaning.

This isnt rose but iron chlorosis looks the same. Its always on the newest leaf growth and gets worse the newer the leaf. The available iron has been limited for awhile. In the spring, soil applications of iron work. In summer and fall you will have to spray iron on the leaves multiple times to get it to work. So get your precautionary iron soil application done early.

Nutritional Problems

            As far as yellow leaves go if they appear on older, bigger stems, ignore it. If these yellow leaves occur and new growth in full sunlight then we may need to look a little deeper on why.

When to Fertilize Roses

Q. Now that it's getting hot, my roses have stopped blooming. Should I keep feeding them or wait until the weather cools and they start blooming again? Can it hurt them when feeding in temps over 100?

A. Roses are typically fertilized three times a year and avoiding months when it’s hot in Las Vegas, (June, July, and August). For convenience I suggest fertilizing on three holidays when cooler: Valentine’s Day, Memorial Day, and Labor Day.

Rose fertilizers are typically high in phosphorus (middle number which in this case is 12). You can use any high phosphorus fertilizer as long as it has some nitrogen and potassium in it. Continued use of high phosphorus fertilizers are not the best idea, So substitute high nitrogen and high potassium fertilizers in the spring and fall months to push growth and keep it healthy.

            On the Valentine’s Day soil application, include your favorite iron fertilizer as well. If you apply iron to the soil, only one application is needed. Generally, do not fertilize any plants during the hot months. If fertilizer must be applied during these months, apply it at half strength.

Reminder About USDA Organic Standards

This is not a condemnation or anything bad about Indian products, just showing you that USDA is trying to protect the integrity of its organic branding. 90% of the time or better, the US organic label means the product was grown compatible with the USDA organic standards. Reminder to Certifiers and Importers: India Requires a Certificate of Inspection for Exports to the United States The National Organic Program (NOP) reminds certifiers and importers that India requires a Certificate of Inspection for the export of organic products to the United States. The Certificate is to be issued by a government-accredited certification agent via India’s TraceNet system. This final export transaction certificate is provided to the U.S. importer to validate the organic status and volume of the exported products. All certified operations receiving organic products exported from India are to obtain the Certificate of Inspection to verify organic status, in accordance with 7 CFR § 205.103, Recordkeeping for Certified Operations. U.S. organic regulations require certified operations to maintain records concerning the production, harvesting, and handling of organic agricultural products; and to make such records available to their certifying agent.  The NOP considers these Certificate of Inspection an essential record to demonstrate good control processes for businesses importing organic products from India. Additional information about this requirement is available on the NOP webpage for organic trade with India: www.ams.usda.gov/services/organic-certification/international-trade/India.

Small Farms Near LV Supplying Meat and Meat Products

This is a link to a KNPR facilitated article regarding small farm supplying of meat products in lieu of closure of the large suppliers like JBS,  Tyson Foods, Hormel, and Smithfield.

Local Meat Producers article

This is a list of "local" farms near the Las Vegas area. Some of these raise their own animals and process them.

Article by USDA on small scale producers locally.

Know the Nevada laws on buying meat from local suppliers (NRS 583).

Opinion piece on the broken supply chain for meat during the pandemic.

In Las Vegas, don't forget Larrys Great Western Meats, although they are not a producer they will cut and wrap meat. Like your old fashioned butcher.

We live in a state that has lots of "cow/calf" operations. These animals are shipped out of state to "fatten them up" for processing. Usually with corn. In Nevada they are mostly range cattle. Know the difference between "corn fed" and other types of feeding operations.

Apricot Bark Lifting and Healing after Borer Removal

Q. With the leaves off, I got a good look at our apricot tree and found two limbs with bark severely damaged. It looks like the bark is completely gone down to the wood underneath.  What, if anything, can be done to salvage these limbs? 

A. Bark easily lifted from tree limbs or the trunk no longer protect anything that’s alive. Plant parts below this bark is dead, whether killed by borers or intense sunlight. Dead is dead. Unlike how animals heal, the living wood surrounding this dead area must “roll” back on top this dead area and cover it.

Limbs were removed from this peach tree due to borer damage and the trunk is healing by "rolling over" where limbs were removed.

            If the damaged area is more than half of the way around the limb then considers removing it. If the damaged area is half or less, remove the loose bark and encourage it to heal properly through irrigation and fertilizers.

            Removing loose bark covering this dead wood helps the plant heal faster and new growth to roll over it. Healing is a waiting game. Healing is faster if the tree is getting adequate amounts of fertilizer and water. You won’t get it to heal faster by giving it excessive amounts of water and fertilizer.

This purple leaf plum had borer damage, heavy, in a major limb facing the sun. That limb died but the tree is still alive. To get it to heal fast, make sure it has adequate water, remove weeds (and grass) growing near it and fertilize twice a year (half in the spring and half in the fall). Make it healthy and encourage it to heal.

            Take a sharp, sanitized knife and remove all loose bark down to fresh wood. Remove all the loose bark and slightly cut into the living wood surrounding this dead area. You will not harm the tree by cutting into the living wood if the knife is sanitized and it will heal faster.

Borer damaged areas are "skinned down" to living wood with a sharp, sanitized knife and then let it heal. 

            Sanitizing the knife, just like the surgeon’s scalpel, will keep serious disease problems from entering the tree that might slow down the healing or worsen the tree. The tree will heal quickly if it is healthy. But this knife must be sanitized with alcohol or a good household sanitizer before cutting away at it.

            It is possible that apricot, unlike many peach and nectarine, will sucker or show new growth below this damaged area. If the limb must be removed, select a sucker growing in a good direction to fill the vacancy left by removing the limb. If the limb remains, remove the suckers and let the wound heal.

Where Can I Get a Moringa Tree?

Q. Can you tell me where I can purchase a Moringa tree to grow in Vegas?

This is one of our Moringa (Mallinggay) trees at our farm in the Philippines. It is harvested for its leaves for use in cooking some local dishes. It is now cut back and suckering profusely.

A. Moringa is a tropical tree that freezes to the ground during the winters we get below freezing temperatures. Most of the attention given to growing Moringa is on leaf production. Winter freezing for this tree in our climate is not critical because it can sucker from its base each spring.

Moringa or Malunggay leaves used for cooking.

Note: there is a growing interest in many places in "food forests" and the health benefits of Moringa. At our Moca Farm in the Philippines we have about 20 Moringa trees, called locally Mallunggay. We use the leaves as a condiment and cooking ingredient for many local dishes.

Moringa cut back for harvesting leaves. This tree suckers nicely from cut stumps making harvesting easier.

           I don’t know any place locally where you can buy one. There are several people in Las Vegas with success growing Moringa in their yards. The tree is easy to propagate from stem cuttings if you know someone who will permit you to take cuttings. We use 2 and 3-inch diameter stem cuttings from our existing Moringa trees (Malunggay in Tagalog) on our farm in the Philippines. The seed is also sold online from nurseries located in subtropical and tropical climates.

           In Las Vegas, I would use thumb diameter cuttings taken in spring and grow them in a protected location in containers until leaves are seen. The following year replant them into their final location. Otherwise, start the tree from seed which can be purchased online.

Note: After this was published in the local newspaper, one reader sent me a note and said she would get seed from her Moringa tree and provide it to whoever wants it. If you are interested. Let me know and I will get you in touch with her.

Desert Horticulture Podcast: Growing Roses in the Desert

Roses are relatively easy to grow in the desert and provide lots of flowers IF you pick the right variety, plant them in a good spot and care for them correctly. Learn how in this podcast.