I hope these answers will help you if you have similar questions.
Question: How do we control squash bugs?
Answer: These half-inch-long bugs are dark brown and have a black diamond on their backs. Look under the leaves where these bugs do their damage. They lay clusters of eggs on the underside of your squash leaves. They also attack cantaloupes, cucumbers, watermelon and other cucurbits. They emit an unpleasant odor when crushed.
Hand-picking them is the best way to control them. Or trap them by placing moist boards under your plants where bugs like to cool off. When you find them on the board, “squash” them. Or vacuum them up like Master Gardener Janet Knight does. If you do use pesticides, you get the best control when the bugs are in the nymph stage.
Q: Why do I have so much twig dieback on my flowering plum tree?
A: This is a result of a flowering plum crying for iron. Not many of us recognize iron deficiency on these trees because it doesn’t give the typical symptoms of yellow leaves with green veins. Examine the leaves closely; they take on a yellowish look. Hold the leaves up to the light and if the veins are darker than the normal purpling, the tree needs iron. If you don’t correct the problem, bores eventually attack the plant, so apply iron chelates to your tree.
Since you apply only a small amount to your tree, mix the iron into a 5-gallon bucket of water and drench the area under the tree. Follow with a deep irrigation to move the iron to the roots. It takes a while for plants to respond, so you can spray the iron directly on the leaves for a quicker response.
Q: My corn is getting ready to tassel. What I can do to control the corn earworm?
A: Once you see the silk starting to turn brown, apply a few drops of mineral oil to the silk. Browning signals that pollination took place. The moths don’t like to lay their eggs in sticky places. You could also spray Bt on the corn leaves over the silk.
Q: I think my old cottonwood tree is about dead and I want to know if I can save it. Can I?
A: If you have any doubt, Dennis Swartzell of Horticulture Consultants said to contact a professional arborist to look at your tree. Since we don’t see these trees in our landscapes anymore, maybe there is something the arborist can suggest to save yours.
Q: Why aren’t my zucchini plants setting fruit?
A: The initial flowers on vine crops are male flowers but females eventually come along. Check behind the blossoms to see whether they are male or female flowers. Male flowers sit on top of stems; female flowers have miniature zucchinis behind them. If you have lots of female blossoms, you may not have much bee activity. In either case, dab a cotton swab on the center part of male flowers to collect pollen and transfer it to the female flowers. For best results, make your transfers early in the morning.
Q: How can I prevent my acacia from producing seeds?
A: Give Monterey Chemical in California a call at 559-499-2100 and ask if its Florel Fruit Tree and Shrub Regulator will give you any relief next spring when the acacia’s in bloom. We use Florel to prevent olives from setting on and the company has tested the product on other trees.
Q: Why are the leaves on my potted avocado tree burning? When the burning appeared, I gave it a couple of shots of fertilizer.
A: First, never fertilize a sick plant until it’s well. You overfertilized it and then didn’t water thoroughly enough to flush the salts away. Anytime you fertilize a plant, you are adding salts. Follow any feeding with a deep irrigation to move the fertilizer to the roots and clean out the remaining salts in the soil. Pay close attention to watering as the heat draws moisture from your container fast.
Q: My pomegranate is next to my house and the pest control operator sprayed the area for termite control. Can I eat those pomegranates?
A: Find out what your pest control operator used. If it’s systemic, the roots can take it up and you can’t eat this year’s fruit. If it doesn’t go through the roots, the fruit will be OK.
Linn Mills writes a garden column each Sunday. You can reach him at firstname.lastname@example.org or call him at 702-526-1495.