No tree will thrive in desert without water

Q: A few years ago I had a bubbler system installed to water my trees for my desert landscaping. They did not do a good great job. It has gotten plugged a few times and the trees do not get enough water. I have gone through four trees and maybe another. Would you give me some names of trees that are truly drought resistant?

A: I hesitate giving you suggestions on plants because that is a highly subjective decision and, secondly, without a reliable irrigation system nothing will work in our desert except maybe Joshua trees. In our desert there are no ornamental and shade trees that will survive or look good without a good irrigation system.

Make sure your irrigation system has a 150-200 mesh filter installed somewhere before the water reaches the emitters. This will reduce plugging. Make sure that when you or anyone repairs a drip system that they do not use a pipe-cutting device, as that rips the piping. Also, do not use a hacksaw or other pipe cutter that uses teeth to rip at the pipe. This will leave debris in the lines that will plug your emitters.

Use only a cutting device that has an unserrated knife edge to cut the piping, such as a PVC pipe cutter. They are more expensive but will actually work quite well. Once you have a reliable irrigation system then you can plant some good stuff.

Q: I've had raised vegetables beds for three years now. I attended a lot classes the first year, then got busy planting and am not in contact with gardeners anymore. Do you still recommend calling the University of Nevada Cooperative Extension Master Gardener help line? Or, which classes are most helpful for nonbeginners?

A: I sure do. The master gardener help line can be reached any Monday through Friday from 8 a.m. to 5 p.m. The volunteers still work and meet at the orchard in North Las Vegas on Tuesdays, Thursdays and Saturdays from about 7 a.m. until about noon or so. Stay tuned. I am currently looking for a place where I can continue to teach.

You can call the help line but much of the information just depends on your question, how detailed it is and who is there to answer. Sometimes when technical questions match the experiences of the volunteers, they can be extremely helpful.

When asking me questions it helps if you can take pictures and send them to me . You can also access my blog at www.xtremehorticulture.blogspot.com; I post answers to questions there as well.

Q: My lawn was sodded with tall fescue lawn grass a few years back and this past fall noticed I still have two problems. The pictures are attached. The first are 5-10-inch circles which are brown in the center with very dark green grass around it. The second are areas around the edge where there is a patch of dark green grass and then 10-15 inches of bare ground around it. I am really hoping you can provide an explanation and solution to resolve these.

A: The picture with brown 10-inch circles with dark green on the outside looks like damage from a urinating dog. Urine results in a small round brown area where the grass is darker green around the dead spot. Readers can see these pictures by following my blog.

The urine is too high in salts (urea, a salt high in nitrogen) and burns the immediate area around where it is applied. As the urea moves into the surrounding soil, it dilutes, reducing the burning, and then acts like a fertilizer high in nitrogen. Nitrogen fertilizers turn grass a dark green.

The other picture, with 10 to 15 inches of bare ground around a green area, looks like there is a sprinkler head in the center of that small green area . If that is the case, I am guessing the popup is not "popping" high enough. Make sure it pops up all the way and is not getting blocked. Make sure your irrigation sprinklers are 4 inch and not 2-inch popups. Two-inch popups do not pop up high enough to spray evenly above the top of a grass mowed at 2 inches in height. The grass height interferes with the water spray.

Also check your water pressure. It should be in the 40-50 psi range for most popups. If it is a lot higher than this, then your sprinklers are probably "fogging" and not delivering the right sized droplets to get even coverage over the lawn. Install a pressure regulator to drop the water pressure in the appropriate range recommended by the irrigation manufacturer .

Your tall fescue does not look very luxurious in general. It would improve from some good lawn management practices. Tall fescue is best if mowed no shorter than 1½ inches, and 2 inches is even better. Use a mulching mower and return the clippings to the lawn .

Try aerating the lawn, which can be done any time of the year, and follow this with an application of a good quality lawn fertilizer. If you are returning the clippings to the lawn, then fertilize Labor Day, Memorial Day and Fourth of July. Be sure you also make an application around Thanksgiving to keep your lawn dark green through the winter .

Q: I live in Las Vegas and want to grow baby cucumbers for pickling. I tried to grow some last spring but was not successful. I didn't realize until the plants were about 1-foot tall that I was supposed to thin them out. I did thin them but it may have been too late. The plants looked good and grew well but when they began to flower, the little tiny cucumbers got very dry and hard and shriveled up.

The pot was getting full sun most of the afternoon so my husband built an open lattice over the top for some light shade. As the later part of June approached, the plants were not looking good and I gave them up, with the intention of trying again, maybe in the fall when it's cooler .

A: Cucumbers have a fairly narrow time for production here -- from about late March or early April to about June -- as it gets too hot. They can suffer from chilling damage if temperatures get below about 50 F.

You can plant again in September since they have a fairly short production time, about 60 days. Soils should be well composted and fertilized before planting. No lack of water for these plants or you will have problems. Soils must be kept moist, so cover the soil with straw mulch or other mulch you can till or spade in afterwards.

You will have less waste if you trellis them rather than letting them lay on the soil. In the warm times you will pick three times a week. The easiest to grow is Armenian cucumber but it will not make very good pickles. Others to try for pickles might be Eureka and Valispik. Other vegetables and even fruit make great pickles as well.

Bob Morris is a horticulture expert living in Las Vegas. Visit his blog at xtremehorticulture.blogspot.com.