October "In The Grow" - Indiana Yard and Garden - Purdue Consumer Horticulture

October “In The Grow”

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 are susceptible to several blights. Yours sounds like phytophthora blight, which is caused by a fungus. It attacks the stems, leaves and buds. Infected areas are dark brown or black and have a tendency to become leathery. Sometimes the disease causes black lesions several inches long at the base of the stem, resulting in wilting and death.

Good garden sanitation is your first line of defense. Begin with a thorough clean up of old, infected stems, leaves and other plant debris in the fall. Pull the soil away from the crowns and cut off the old stems as close as possible to the crown without injuring the bud. Thin out crowded plantings, and plant peonies in well-drained soil.

If a mulch or other covering is used for winter protection, it should be removed early in the spring before shoots emerge from the soil. Remove any wilted or rotted shoots as soon as they are detected.

Although there are fungicides registered for control, none are totally effective at disease suppression, and none actually “cure” the disease, only suppress it. In addition, accurate timing of applications early in the season and the need for thorough coverage and repeated applications makes the use of fungicides rather expensive and time consuming for the average homeowner.

Q. We have several 5- and 10-year-old peach trees that are fully producing, which have been damaged by a farmer’s drift of herbicide. We are sure they are dying. Can you tell us where we can find out the value of these trees and the fruit we are losing?
– Carol Waldrep

A. To value this year’s crop, estimate what your yields would have been, based on previous years’ crops, then price according to current you-pick markets. However, if the tree is dying, you’ll need to contact your local Extension office and maybe your insurance agent. Tell your Extension educator the name of the herbicide, if you know it. It’s possible that the herbicide that drifted is one that will cause damage to this year’s crop, or set the trees back, but not kill the trees outright.

Further information is available in Purdue Extension Publication ID-184 (Diagnosing Herbicide Injury on Garden and Landscape Plants), which is available through your county Extension office or online at http://www.agcom/purdue.edu/AgCom/Pubs/ID/ID-184.html.

Q. We have a problem when our golden delicious apples begin to ripen on the tree in our yard. There is a bee that has been identified as the Giant European Hornet that likes the apples but doesn’t bother a tree nearby that ripens late in August. This hornet drills a little hole in the apple skins and consumes all the flesh of the apple, leaving nothing but the outside peeling. From the sources we have contacted, we have been unable to learn where this hornet nests. Can you tell us where we might look for this nesting place?
– Chalmer Harrison, Dubois, Ind.

A. The European hornet is fairly large (1.5-2 inch) and somewhat hairy. It builds colonies inside structures (wall voids, attics and sometimes basements). Control of such colonies is best left to a professional pest control operator. Colonies can be very large and are often located far from the entrance hole, deep into the structure. In such cases, special application equipment is needed to ensure that the insecticide penetrates deep into the structure and contacts the colony.

Q. For the last two years, we have had trouble with our cabbage. It looks good with large, green leaves, but it refuses to form heads. We have never had this sort of problem before. The weather has been good, with about the right amount of rainfall. We have 10 cabbages; all the plants are big, but not one of them has a head. Can you give me any answers?
– Ray R. Jones, Lamar, Ind.

A. Cabbage and all members of the cabbage family, such as cauliflower and broccoli, require cool temperatures, adequate moisture and high fertility to produce high yields of quality produce. Any condition that causes stress during the growing period can result in some form of crop failure. And larvae feeding on early buds can cause the heads to abort. Fertilize and keep an eye out for insects.

Q. A couple of years ago, I planted the seeds of a persimmon tree in one area. Now I have maybe 30 trees coming up. They are 2 feet tall on average, and I’m afraid to transplant them. I tried this once before, and they died. Should I leave them as is or cut some of them down? Thanks.
– John Matthew, Orleans, Ind.

A. To thin the crop for proper tree spacing, you’ll need to cut some down or transplant them. If you really want 30 persimmon trees, transplant them after leaf-drop this fall or in late winter/early spring before new leaves emerge. Ideally, give each persimmon tree a 20-foot by 20-foot space. I hope you really like persimmons! My mouth puckers from the memory of my dad’s persimmon ice cream.

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