Q: We have an Elberta peach that we harvest in August and the fruit is always small and on the mushy side. Are there better peaches we can grow?
A: You may be doing something wrong with your Elberta peach. Our July Elbertas, Early Elbertas and Lemon Elbertas all do well — about a 4.0 on a 5.0 scale. All of our Elbertas are good peaches and not small if you thin them and not mushy if you get them off the tree when you should.
Q: Something is eating the leaves on my lemon tree. What can I use to prevent this? I found a product at the nursery and it says you can apply it to the soil to control bugs.
A: If something is eating the leaves I would not be too concerned unless it is really eating a lot of leaves. We really have to be careful when we apply these types of poisons on the soil and around the food we eat.
If this insecticide is taken up through the roots and spread through the plant to kill a bug, it might also have small amounts in the fruit as well. The insecticide dissolves in water and moves down through the soil where it is absorbed by the roots. Once absorbed, it moves up through the plant providing protection from insects.
These types of products are called systemic insecticides and move into new growth after the application. The insecticide stays inside the plant and gives it protection from bugs. Rain or water cannot wash off this internal protection and you cannot wash it off by scrubbing the fruit.
There is an old saying, “The dose makes the poison.” Insects, because they are small, require less of a poison to kill them than larger animals. Even though insecticides have a label to tell you what you can or cannot apply them on, it does not mean that the products are entirely safe.
If you have to use an insecticide to control damaging insects, then I would recommend something that you spray on the outside of the plant rather than something that is taken up by the plant through its roots. In many cases, the insecticides that are sprayed on the plant will wash off or degrade in the environment.
It is up to you whether you want to purchase this product and use it. As for me, I would not eat fruit from a tree where an insecticide was applied to the soil and taken up by plant roots.
Q: I have bottle trees planted next to the house and, for some reason, the one in the middle is losing leaves on the bottom branches. The trees are getting watered two times each week for 40 minutes. I cleared out the rock mulch and replaced it with cedar mulch around the base of the tree. I lost a bottle tree last year so I’m trying to figure out why.
A: Bottle trees represent about 15 or 20 different types. All of them have a swollen trunk that, some people speculate, they use for storing some water during dry periods. We typically use only one type of bottle tree in the valley.
The cedar mulch won’t add any nutrients to the soil but it will slow evaporation of water from the soil surface. Bend side branches without leaves to see if they are dead. If they are still flexible and don’t snap, they may come back when it cools.
Remove any branches that are growing toward the house. Planting those trees in that location was not the best idea.
I remember these trees being brought into the valley as early as the late 1980s during our first push on desert landscaping. They were brought in by landscape contractors and architects because they were being used in Southern California.
The first problem I remember was irrigation. People did not know that these trees required watering less often. They were watering them much like any other landscape plant. These trees are susceptible to overirrigation.
Although not a desert tree like the Acacia, it does handle arid climates and infrequent waterings. These waterings, when they do occur, should flood the entire root system about two to three times a month during the summer. The next irrigation should not occur until the soil is dry or you run the chance of getting root rot and the tree may suddenly die during the summer heat.
The next problem was how they were being used. The tree needs to be in full sun. They should not be planted against a hot south- or west-facing wall. Young, green trunks of this tree can get severe sun scald in these locations followed by limb and branch death.
Q: I used a product called Green Light. It contains chelated iron, copper and zinc for correcting plants that are yellow. Is this similar to the chelate you talk about for our soils?
A: I know the Green Light chelate product and it will not be effective in our tap water, which is alkaline, or our well water. It also will not work in most of our soils because they also are too alkaline.
This product will work if you adjust the water with some acid and use it as a spray on the leaves of the plant. If you have a gallon of water, you can put a small amount of vinegar or pool acid used to adjust alkalinity of pool water.
If you are using pool acid, test the water with some pool pH strips or a kit. If you are using vinegar, 2 or 3 tablespoons of vinegar in a gallon of water should be enough. After adding the acid and mixing the water you can add chelates to the spray solution.
Follow the label directions and then add two more things to your mix. First, add a small amount of liquid fertilizer or a powdered fertilizer that dissolves in the water. Second, add about a teaspoon of liquid detergent to the finished spray mix.
Make sure everything is dissolved and thoroughly mixed. This spray solution must be used soon after it is prepared. Use it all up. Don’t save any of it as it will probably not last. Use this mixture any time temperatures are cool.
Only spray long enough until you begin seeing this liquid run off of the leaves’ surfaces. Spray both sides of the leaves; once over the tops and a second time with the spray pointing up so the undersides of the leaves are coated as well.
The addition of liquid detergent to the mix will help move the solution inside the leaf. The small amount of fertilizer will make the chelate more effective. If leaves have already become quite yellow, spray them once every few days for about four or five applications.
Now is the time for ordering your bareroot fruit trees for a late January or February planting date. The University of Nevada Cooperative Extension Master Gardener Orchard in North Las Vegas will again order 500 fruit trees from Dave Wilson Nursery, a California wholesale provider of quality fruit trees. We are selecting fruit trees only that are highly recommended for our Southern Nevada climate.
These trees are bareroot and not in containers. Contact me by email, firstname.lastname@example.org, and I will send you a list of fruit trees available and how to proceed or visit my blog, xtremehorticulture of the desert.
Bob Morris is a horticulture expert living in Las Vegas and professor emeritus for the University of Nevada. Visit his blog at xtremehorticulture.blogspot.com.