The following question and answer columns are currently written by B. Rosie Lerner, Purdue Consumer Horticulture Extension Specialist and are distributed to news media around the state by the Purdue University Agricultural Communications. Columns from June 1995 - January 2006 were authored by Bev Shaw, Advanced Master Gardener.
Q. My ornamental grasses are still in place in my yard. They looked nice all winter. When and how do I cut them back? When do I divide them? –Fleet Walker, Nashville, Ind. A. Ornamental grasses can be cut back any time from fall to spring, but I like to leave them in place over the winter. They bring motion and texture to the garden when they’re desperately needed! By late winter, heavy snows and […]
Q. I had a severe problem with black spot on my roses last season. What can I do, and what can I use to prevent it this year? –Ruth A. Beer, Syracuse, Ind. A. Black spot is a serious problem on roses in Indiana. Black, circular spots with fringed or uneven margins form on upper leaf surfaces in the spring and summer. Spots may also develop on canes and leaf petioles when the infection is […]
Q. This spring I got two hibiscus trees and discovered they had spider mites on them. I took them outside and fought them all summer. When I brought them inside, the mites were still there. One day, I sprayed with a spray that I was told to use. They lost all their leaves. Now they are starting to get new leaves. How do I keep the mites off them? How do I care for a […]
Q. I have one ‘domestic’ walnut tree. Every year, just before I think they are ready to be harvested, I come to the tree to find it has been stripped bare. I assume the culprits are squirrels. How can I tell when they are ready so I can get to them first next year? – Irvin Goldstein A. Collecting the nuts before they are truly ripe would lower the quality of the crop. You’re better […]
Q. I have two dwarf apple trees that are four to five years old but have never produced any fruit. I fertilize them every fall. Are there other things I should be doing? – Duane Nagel, Rensselaer, Ind. A. Are your trees blooming? It’s not unusual for dwarf trees to need up to five years before becoming mature enough to bloom. Overfertilizing with nitrogen, a lack of sun or improper pruning may cause a lack […]
Q. Three years ago, I transplanted a couple of peony bushes, which were nice and green, from a neighbor’s yard. Last year, they were green in the spring but the leaves started turning dark brown, some black, with no blooms. This year was the same, except they had a few blooms before turning brown and black. Why is this happening, and what can I do to save them? – Jane Clary, Rockport, Ind. A. Peonies […]
Q. My rhubarb has some type of bug. It’s planted at the edge of my garden. It’s not as hearty as it was in the past, and now it has brown spots. – Phyllis Clark A. Crown rot can cause brown, sunken, water-soaked spots on the base of the leaf stalks. Leaves yellow, and stalks collapse and die. The disease thrives in waterlogged, heavy soils and attacks the crown and base of the stems. In […]
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 […]
Q. I have magic lilies that have not bloomed for two or three years. The foliage comes up in the spring, but there are no blooms in the summer. Do I need to move the bulbs? If so, when? – Marian Fouts, Walkerton, Ind. A. When bulbs (including daffodils) get crowded, they will cease flowering. If you have a thick mass of magic lilies (Lycoris &emdash; also called surprise lilies, naked ladies and resurrection lilies), […]
Q. I am wondering what kind of tree, besides a willow, likes moist areas. I have an area in our yard that does not drain well and was hoping to solve the problem by using a tree. I can’t use a willow, due to my neighbor not really wanting one. He is worried about the roots. Thanks! – John D. A. Plants may take up some of the water and could reduce the excess moisture […]