Q. I was given a large hibiscus plant as a house-warming gift. Several months ago, the leaves started turning brown, and I found tiny, white, flying bugs on both sides of the leaves. I bought a pesticide that was labeled for hibiscus and control of whitefly and mealybugs. I am on my second can of the spray, but the plant has not improved. What can I use?
-Elois Goerz
A. Whiteflies are common pests of houseplants and are quite persistent if you don’t reapply pesticides at the right time during the flies’ life cycle. You can keep the population down by simply taking a strong stream of water to the plant, if it is outdoors. This knocks off many of the pests but won’t completely control the situation.
You can purchase sticky, yellow traps and hang them in the hibiscus. The whiteflies are attracted to the yellow color and once they land, they can’t take off again. This is an effective means of control. Or treat with diazinon, malathion, orthene or insecticidal soap. Make sure that you follow the directions concerning reapplication, so that you treat new whiteflies as they hatch.
Q. My iris plants have big, healthy leaves but no blooms. I have tried everything that has been recommended but have no flowers. Also, I have quince bushes with thorns and red flowers. They have large apples in the fall, and I wonder if those are what is used to make quince jelly.
-Ida Maye Smith, Sunman, Ind.
A. Bearded iris have a tuberlike rhizome at their base. That rhizome must be planted horizontally and exposed to light. Loosen the soil, and form a ridge to lay the rhizome on. Let the roots go down into the soil on each side of the ridge, then bring soil up along the sides of the rhizome but not over the top. Iris with buried rhizomes will grow but not produce flowers.
Too much shade on the entire plant can also cause a lack of flower production. When you relocate your iris, make sure that you plant them in full sun. While you’re lifting them, inspect each rhizome for borers or rot. Discard any infested or rotten portions and replant only healthy sections.
Your quince are bearing the fruit used to make jelly. Stock up on sugar, since the fruits are quite tart. Recipes are available in cookbooks that include canning and preserve recipes.
Q. We have a lake home in northeastern Indiana. In November, we planted 100 flower bulbs. We put three boxes of mothballs over the tops of the two flower beds. The next day, nearly one-third of them had been dug out. We have a lot of chipmunks, squirrels and raccoons up there. Help! What do you suggest?
-Robert A. Bolen, Greenville, Ohio
A. Mothballs are toxic and not labeled for use in the garden. Exclusion is the best way to reduce animal damage. As you know, they’ll just push deterrents out of the way to get to the tasty bulbs. You can pin down hardware cloth over the bulbs to keep chipmunks and squirrels from digging them up. Once they are rooted in, they are less likely to be uprooted by animals.
Many homeowners need to actually create hardware cloth boxes around the bulbs to protect them from field mice. Trapping is another option. Moles are insectivores and do not eat bulbs. Try planting daffodils next time. Most animals will bypass daffodils for a tulip or crocus every time.
Q. We have a new home. What would make a great border–not a shrub–that blooms all summer? Are there any trees with burgundy leaves that grow quickly and put out a lot of shade? If not, what tree grows quickly and makes great shade?
-Alan Line, Marengo, Ind.
A. Only annuals bloom all summer, so you could consider a wide range of plants.
I don’t know your height, light or soil limitations, but there are several long-blooming perennials, including Coreopsis ‘Moonbeam’ and the daylilies Hemerocallis ‘Stella d’Oro’ or ‘Happy Returns.’
Trees with burgundy leaves include the Crimson King maple, smokebush and cistena plum. Of these, the Crimson King maple is much larger and less troubled by insects and diseases. Some other fast-growing, shade-producing trees are ash, maples and honey locusts.