Cutworm season will last for a couple of weeks

This is cutworm season. These are the larvae, or immature forms, of a moth. They emerge from the soil at night, crawl along the surface of the ground until they find a plant to nibble on and then cut the plant off at the soil level. Some actually drag them to their burrows in the soil. Most just eat enough to cause the plant to fall over. They return to the soil to avoid the daylight and natural enemies.

This onslaught will last only a couple of weeks and the majority will be gone. Some cutworms are climbing cutworms that climb the stems of herbaceous plants and eat buds, leaves, and fruits and vegetables. Organic gardeners have used paper collars placed around the plants to protect them.

Cultivating the soil around young plants may be effective provided you don't damage new, growing roots. A thick mulch may also give you some protection. Biological warfare for the gardener includes Bt, which is a bacterium that is very effective on worms that come from moths. The Bt should be mixed with a bait of some sort such as wheat bran. The bait is moistened enough to make it wet but not dripping. The bait should be distributed in the evening for cutworms.

Chemicals for the organic gardener that can be tried include diatomaceous earth (DE), which is an abrasive to the crawling cutworm. It can be spread around each plant in a circle. Traditional pesticides include diazinon, sevin and malathion. Follow the label.

With all this plant growth in the desert going on right now, guess where the insects that will be feeding on this banquet are going to go when it dries up -- your yard. The yards closest to desert areas will be hardest hit. I see a big grasshopper and cricket problem emerging this year. There is a grasshopper bait that could be spread now that will help control this type of intruder. It is called Grasshopper Spore and should be available from your local nursery. If not, it is available over the Internet and is a natural product containing a parasitic organism specific to grasshoppers, locusts and crickets.

Small side shoots or sprouts can be seen coming from the trunk and larger limbs on many small trees now. Should they be removed? Unless they are a nuisance or must be removed because of appearance, I would leave them on. Suckers coming from roots and very vigorous new growth should be removed. These are called watersprouts and sap the energy from other parts of the plant and are seldom productive. However, if the new growth appears normal then leave it alone. This is for two very good reasons:

Small shoots coming from the trunk or large limbs produce leaves. These leaves produce sugars for the plant. The area closest to the leaves receives the most sugars from these leaves. These small shoots contribute greatly to the diameter growth of the trunk and large limbs. This type of growth on the trunk and large limbs makes the plant much stronger and more capable of withstanding strong winds and stand on its own without staking.

These small shoots also help to shade the trunk and limbs from our extremely intense sun. This sun can scorch and kill young wood exposed to it directly. Remove small shoots when they reach the diameter of a pencil. Think about these points first before removing these small shoots or suckers.

For the lawn areas right now the primary focus is on weed control. I would concentrate on getting a balanced but high-potassium fertilizer to prepare it for the heat. The balanced fertilizer will crowd out most of the weeds after a few mowings.

Question: I just purchased some roses. I have had numerous suggestions on how they should be planted. Some of this information seems contradictory. How should I plant them?

Answer: Each person who loves roses has their own way of planting them. I try to stay away from making recommendations about the use of soil amendments such as B1 vitamins, root stimulators, bone meal or dolomite. For every person I've talked with that swears by their formula for success, I can talk to someone else who has a different idea about what works. This is oftentimes a personal preference and reflects what has worked for them in the past.

Information from people who have had great success with roses is important information to have. However, this type of information should not be given the same degree of importance as some basic do's to follow that are necessary when planting in our soils.

Our soils are always high in salts, low in organic matter, usually have poor drainage and are alkaline. Always flush our native soils with water before planting. Salts in our soils can be many times higher than is safe for roses. After the hole is dug, fill the hole with water several times and let it drain. Running water through the planting hole prior to planting will flush salts that may be harmful to salt-sensitive plants. Every 6 inches of water in the planting hole will lower the salts in the soil, providing there is good drainage, by half.

Even when using soils manufactured for landscapes, make sure the soil drains in a reasonable time. What is a reasonable length of time? It would be nice to have a soil that drains about one inch per hour. There are very few native soils in the valley that will drain that quickly. Your soil must drain faster than one-quarter of an inch per hour or it will cause severe problems for your roses. Soils with poor drainage will cause yellowing leaves, poor growth, scorching of the leaves and potential dieback and death.

Our soils are alkaline or low in acid. Most plants that are not native to desert regions will perform better if the soil is more acidic. You will never permanently correct this condition in our soils. The best you can hope for is a temporary lowering of the pH. There are two common ways to accomplish this; add sulfur to the soil at planting and then to the soil surface annually and add well-rotted, organic amendments as well. The better way in the long run is to use organic amendments. Rotting, organic amendments will help to add acid to the soil and provide many organic chemicals important to the health of roses. If the organic amendment is not rotten or decomposed when added to the soil, it may rob the roses of needed nitrogen and cause them to turn yellow and stunted. A well-rotted amendment is all the same color throughout; dark brown or black and has a characteristic musky odor.

Q: I have had some damage to the petals of rose flowers. The edges of the petals are brown.

A: Thrips are small insects, rarely as long as one-eighth inch and cause damage to many other plants. They have been very destructive to nectarine fruit in this area. They live in flowers and other parts of the plants feeding on the sap. They are a serious pest of fruits, vegetables and flowers. They are serious because they are so difficult to control.

Thrips are very active insects. They spring or fly readily when disturbed. When you have thrips on a plant, they can be confused with aphids at a distance. When you touch the plant, however, they fly up in a cloud if there are many of them.

The damage they create is done by their feeding. When feeding, their mouth rips tender plant tissue and then sucks the sap from the torn tissues. This damage to flower petals makes a new flower look like it was an old flower in left in a cooler; wilted, brown and discolored.

Early damage to roses causes the buds to be retarded and distorted. On nectarines it causes damaged fruit with scarring and sap crystals emerging from young fruit.

Control is difficult. Most likely the insecticidal soaps and oils will not work but it is worth a try. We are using Neem applications as directed by the label. Pyrethrum-based insecticides would be my next choice but they are tough on predatory insects like ladybugs and lacewings. If that didn't work, then multiple applications of a traditional pesticide, labeled for thrips, would be my last attempt. Always read the label of any pesticide before purchasing and using.

Bob Morris is a horticulture specialist with the University of Nevada Cooperative Extension.