IN THE GARDEN

Arkansas Democrat-Gazette Bletilla illustration
Arkansas Democrat-Gazette Bletilla illustration

Q I have a couple of questions about my wonderful hardy orchids that I have had for years. They produce beautiful little blooms, and I'm so happy with them. I have them in three places. If it is possible, I would like to move one "bunch," because they are rather consumed by an autumn fern. I think the roots are shallow and delicate. When would be the best time to transplant? My other question concerns the leaves. They are huge, and in the past I have let them go away on their own when cold weather comes on. I'm wondering if I should be cutting the leaves off after a certain point? I have one more question ... what about the seed pods? Leave them alone, keep them or plant them -- they have naturally produced more plants over the years.

A Hardy orchid or Bletilla is a wonderful, old-fashioned perennial that does well in full morning sun and afternoon shade, or filtered sunlight. It is not a fan of afternoon sun in our hot climate. The foliage should be left alone until it begins to die back on its own, then you can cut and clean it up. Once the seed pods are mature, you can harvest them and either share with friends or try growing the orchid from seed. The best time to move them would be in the fall as they are going dormant or in the spring as they are emerging. I would prefer a fall division, to allow the plants to recover well before the bloom period.

Q I have a small hydrangea plant that I bought in the spring. It is getting black on the leaves. What do I need to put on it to kill the mold or etc.?

A There are two possibilities -- a black sooty mold caused by aphids or other sucking insects, or a leaf spot disease. If you have aphids, I suspect that they drowned recently and that the black sooty mold will wash off. Black spots are not uncommon on hydrangeas in the latter part of the season, and with as much rain as we have been having, I expect the problem to be pretty widespread this year. Cercospora leaf spot is a common fungal disease on hydrangeas. Late-summer rainfall can be a major contributor to the spread of this disease, and we have definitely had more than our fair share. Since the disease is happening this late in the year, spraying with fungicides would do little good. The best thing you can do for both problems is practice good sanitation and rake up all the foliage after it falls off this fall.

Q From one small planting of a purple passion flower vine, it has sprung up everywhere -- rose bushes, yard, iris bed, etc. How can we get rid of it permanently? When the vine is pulled up, it just comes back.

A Even though it is a native plant, in the right conditions, passion flower can become a bit aggressive. The key is to learn to identify it when it germinates in the spring. Either pulling the vines and/or spot spraying with a glyphosate product can help to eradicate them. The longer they are allowed to grow, the more tenacious the root system becomes. If you do want to keep one or two plants, be sure to harvest the fruit before it is fully mature to prevent any from reseeding.

Q What do you suggest for tree roots under large trees? Is it harmful to cover the roots with topsoil? You were "quoted" as having said this was OK, but I was doubtful and need to hear it from you.

A Unfortunately there isn't one correct answer that works for every situation. It depends on the tree species, how much area you are covering and how deeply and what type of soil you have. For example, a dogwood tree can suffer from even a mild covering, where the deep-rooted bald cypress can take covering in stride. If you are just trying to cover exposed roots, why not just use some mulch?

DEAR READERS: Armyworms are everywhere in central Arkansas. Bermuda lawns are hard hit. While we often think the damage is worse in a dry season, high egg survival of fall armyworms is favored by above-average rains in August and September, which we have definitely had.

After a severe fall armyworm attack, the only vegetation left in the yard will be tough stems. Bermuda grass is a favorite host, in particular, lush, tender growth -- which we also have in abundance after the rains. The brown color results from drying of the plant due to dehydration after armyworms chew tender growth.

Fall armyworms tend to feed more actively in the early morning and late afternoon, and they often hide during the peak of the day. In tall forage, they may eat throughout most of the day. Rarely will an armyworm infestation kill an established lawn, but they can kill a newly planted lawn. Products containing bifenthrin, carbaryl, esfenvalerate, permethrin and others are labeled for control. Common names usually include "lawn insecticide" or "grub killer."

Janet B. Carson is a horticulture specialist for the University of Arkansas Cooperative Extension Service. Write to her at 2301 S. University Ave., Little Rock, Ark. 72204 or email her at

jcarson@arkansasonline.com

HomeStyle on 08/27/2016

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