Patience Is Needed to Combat Psyllid Insect
QUESTION: My Eugenia bush has deformed leaves attributed to a bug, which I think is called the blister mite. I have tried systemic sprays with Orthene without success. Is there anything else I can use to get rid of this problem?
ANSWER: The pest you refer to is most likely the Eugenia psyllid, a very tiny chocolate brown-and-white insect with membranous wings. It was first discovered in North America in Los Angeles County less than 10 years ago. It came from Australia. Eggs are laid on new leaves and shoots of the Eugenia plant. When they hatch, the nymphs settle on the undersides of the leaves and feed by sucking sap. The plant reacts by developing a pit around each nymph, and the leaves become severely blistered and distorted. Sooty black mold also tends to form on the leaves. The problem is more severe near the coast; nymphs are killed by hot inland temperatures. Winged adults reproduce year-round.
According to UC Riverside entomologist Timothy D. Paine and others who did the research, controlling psyllids requires patient persistence and includes the following practice: Periodically prune off the succulent new growth required for psyllid development. If you are making jelly or other preserves from the fruit, this is about all you can do, besides discouraging excessive flushes of new growth by minimal watering and feeding. Otherwise, after pruning and flushes of new growth occur, you may spray with Mavrik (fluvalinate) or with Orthene (acephate). These, apparently, are the only control options available so far.
The Pros and Cons of Planting Korean Grass
Q: Can you tell me the pros and cons of a grass called Zoysia or Korean Grass? Does it need mowing? Take sun? Or shade?
A: Korean Grass (Zoysia tenuifolia) is a fine-textured, creeping grass that spreads slowly and “puckers” into fascinating mounds and bumps. For this reason it is not a good selection for a lawn, but it is quite impressive in areas where you want a natural meadow look or where it will not be mowed. It is deep rooted and drought tolerant. It thrives in full sun but can take some shade. During the winter it goes dormant and remains straw-colored for a fairly lengthy period; then it comes back deep emerald green in springtime. It’s fascinating, but not too practical for the average home garden.
Atomic Bomb May Not Get Rid of Nutgrass
Q: Help! I’ve been plagued by nutgrass (nut sedge) since I brought in some topsoil about six years ago. I’ve repeatedly killed my back lawn in the process of trying to get rid of this weed, and I’ve tried multiple products without success. It always springs back to life. I understand there are nuts under the soil that live a long time, and seeds on top. At times I’ve felt that if I could get an atomic bomb I’d throw it back there to see if it might finally do the trick. Any suggestions (besides moving)?
A: I’m not sure an atomic bomb would help! Nutgrass is considered to be one of the world’s most noxious weeds, and now you know why, from personal experience. I have yet to find any spray that will give satisfactory control. However, I have managed to eliminate this horrible green pest from a 9-foot by 9-foot planter with a combination of careful spraying and conscientious spading--over a period of two or three years.
It would be impossible to maintain a lawn or many other plantings in this area during the period of treatment, unfortunately. But this is the only method I know of that seems to work.
This is what I did: First I methodically dug up the patch of nutgrass, sifting as carefully as I could through the soil to remove as many plants and root runners and nuts as possible. Then when new shoots emerged and started growing, I sprayed with Roundup at the most dilute-recommended strength. (This enables the poison to move through the plant slowly and efficiently. A greater concentration of Roundup will deaden the tops too quickly and not travel far enough to maximize the kill. It is important to plan the spraying of Roundup so the area will not get watered or rained on for at least two days after spraying.) After a week or two, the nutgrass started looking sickly and died back. Some time after that a new crop of nutgrass emerged. As the shoots came up, I carefully dug them out, again sorting through the soil to eliminate any more nuts and root runners. The next time around I sprayed with Roundup at low strength; dieback began a week or two later. I continued this alternating procedure for quite some time. I could tell it was working, because the number of new plants coming up was decreasing. It was a matter of dogged persistence, and gradually I “won.” But even now I still have to watch out for delayed starts of long-dormant nuts or seeds. What a royal pain. Good luck in your yard.
Net Cukes Suffering From Bacterial Wilt
Q: I have been planting Japanese cukes with great success until the last two years. The plants look wilted, then they die. It happens to both small and larger plants. I planted them in different locations of my garden, and still the same thing happens. Beans and bell peppers have done very well, but not the cucumbers. What could be the problem?
A: It sounds like your plants may suffer from a form of bacterial wilt that is transmitted by aphids and cucumber beetles. Diseased stems, when cut, may ooze a cloudy liquid as a telltale sign. It is necessary to prevent aphids and cucumber beetles from attacking your plants. Lightweight, finely netted insect barriers completely surrounding the plants will do the trick, but you’ll need to hand pollinate the flowers in order to get cucumbers. Spraying the plants at label-recommended intervals with Sevin or Malathion will also help, but you must be diligent to keep these bugs away. Does anyone else have any other suggestions?
It’s rose pruning time. Order a copy of my easy-to-understand demonstration video, “The Care and Pruning of Your Roses,” from Jack Christensen, c/o Rose Pruning Video, P.O. Box 1231, Ontario, Calif. 91762. Enclose a check for $18.99, including tax and postage. Delivery in 7-10 days.
