One paloverde borer beetle may not mean trouble

Here are some questions that came to me recently from gardeners having problems. I hope my answers will help you, too.

Q: I found a giant dark-brown bug about 4-inches long and an inch wide with long antennae floating in my swimming pool. What is it and how can I control it?

A: It is the paloverde borer beetle. The adult beetles often are attracted to outdoor lights at night. Although its appearance will intimidate you, it is relatively harmless. The adult beetles lay eggs in the soil and they hatch into immature grubs that bore into the soil and feed on roots of paloverde trees, roses, privets, elms, cottonwoods, mulberries, citrus and stone fruit. Its common name is misleading.

After about three years, grubs surface as adults, leaving large holes in the ground. The adults have the ability to fly great distances, so its presence in your yard does not necessarily mean your roots are infested with the grubs. There are other insects such as the cicada that leave similar exit points from the soil. If they become a pest, simply turn out the lights for a week or so and if you are up to it, capture and destroy them.

Q: I have lots of beetles with a triangular design on their backs all under my yellow squash. They are not eating the fruit, but they are very annoying. Any thoughts?

A: You described the squash bug. They feed on the underside of the leaves and enjoy the shade. Control them physically by hand picking or trapping them. Moisten a large board and place it under the vines. Prop one up so they can get under it for shade. A day or two later, destroy those hanging on the board and replace to catch more.

Or you can organically get rid of them by using insecticidal soap or neem. But remember, you must keep after them because there are different stages of maturity -- eggs, nymphs and adults -- of the bugs within the colony and some stages are more resistant to the organics than others.

Q: We have a zillion tiny ants in our yard and paid a fortune to control them last year but is there something we can use? We poured vinegar down the holes but it didn't do any good.

A: With the recent rains, hold off a few days and they might disappear. Bob Stauffer, master gardener for Nevada Cooperative Extension, said for an organic fix, put one part boric acid in 10 parts peanut butter and place it along their trails. Because of the boric acid, keep your children out of the area. If the ants get in your home, rub your cabinets down with white vinegar to deter them elsewhere.

Q: Why did the leaves on my peach tree suddenly wilt? We water every day with a bubbler for 15 minutes, so it is getting enough water.

A: A bubbler running that long every day drowns the roots so they can't breathe and the leaves wilt. Either cut back on the water or drill holes into the soil so the roots can breathe.

Vertical mulching will really help your trees out. Vertical mulching is drilling holes down through the soil about an inch wide and filling them with mulch. It isn't hard to do; buy a Ross root-feeder and attach to your watering hose and let the water do the drilling. Drill the holes down about 2 feet deep to open the soil up so the roots can breathe and the excess water can drain away faster.

Q: What trees can't I plant in Las Vegas?

A: There are only two on the restricted list: the fruitless mulberry and the fruiting European olive. You will find the Swan Hill and Wilson olives available, but make sure they are certified as such or you will find yourself in a peck of trouble with olives all over the place.

Q: I have a mature Chilean mesquite tree and today I noticed several branches with white crystalline nodules on them. Are they any problem?

A: It is normal for mesquites to bleed from pruning cuts, injuries or stress cracks. It may be worse if your tree is stressing for water. It goes back to improper irrigation procedures.

Q: Do you know why we lost four of our six strawberry plants within a week after planting?

A: Strawberries are sensitive to planting depth. If you plant them too deep or too shallow they will die. Always plant them at the same depth found in the container. That is where the roots and stems meet. Planting deeper, the stems rot, and exposed roots act as a wick to dry out the plant.

Q: Why do I have clusters of tiny leaves at the tip end of my peach tree twigs?

A: It is a strong indication your tree is suffering from zinc deficiency. Another indication of zinc deficiency is if the leaves look like they are transparent or almost see through. Apply zinc chelates, but I must warn you it takes a long time to correct the problem. For a quicker response, make up a solution of zinc chelates in water and spray the foliage, but also apply it to the soil for it to work up through the plant. If you can't find it, call Gro-well at 639-0370.

Q: I planted French-lavender shrubs back in April. They have been dying off one at a time with the leaves and then branches yellowing and drying out. They get watered with small sprinkler emitters six days per week, in three five-minute waterings, a half-hour apart each. I'm not sure if I'm watering too little or too much.

A: French lavenders are prone to root rot if overwatered. Also, branches turning yellow is another indication of too much water. You are better off watering less often but for a longer period of time.

Q: We have four cape honeysuckles that died to the ground during the winter freeze. They came back like gangbusters, but no blossoms yet. How long will it take for them to recover? Our hummingbirds are thirsty.

A: With them freezing back, you lost the blooming wood. Hang in there; they will be back in business next year.

Q: We had a supersweet cantaloupe and want to save the seeds. Is there any set process to follow?

A: Don't save the seeds. Plants such as melons and cucumbers with separate male and female flowers are cross-pollinated, so they will not breed true. The quality always seems to go down in the next generation.

But you may want to save seeds from squash and gourds from year to year, just to see what the new fruits will look like. I know of a gardener who does this, and he comes up with all shapes and sizes. The offspring after several generations eventually reverts to warty gourds. His progeny was always the talk of a small farming community.

Linn Mills writes a garden column each Thursday. You can reach him at lmills@reviewjournal.com or at the Gardens at the Springs Preserve, 822-7754.