Q We got delayed in pruning our Knockout roses. I kept one of your columns from several years ago on when to prune, so I know we are a little late. They are putting on new growth now, and so we wonder if we should go ahead and trim or let them go. Should we cut them to 18 inches or not now?
A Many people didn't get their roses pruned due to heavy rain and fluctuating temperatures. Regardless of why you didn't prune, you still need to prune them now. Late pruning will delay your first blooms, but you will have a more vigorous plant with more flowers for the season if you do prune.
Q We know that the weather has not been cooperating with us over the year. I am about to make changes in my flower beds around my place. I want to move the amaryllis to another bed as they need to be thinned out. I see they are growing back from dormancy ... is it too late to transplant them within a couple of weeks, weather depending?
A Dividing amaryllis bulbs would be better done as soon after they finish flowering. If you thin them now, it can affect their blooms. If that isn't a concern, it won't hurt to thin and move them now.
Q I bought some Miracle-Gro plant food in bulk a few years ago. Do you think it is still good to use or do I need to throw it away and buy new for this year?
A If you have stored the fertilizer in a cool, dry place, it should be fine. If you bought the powdered type, if it is not clumped together, it should be safe to use.
Q Can you tell me the name of the attached plant?
A It is a houseplant called Calathea. Most people grow them for their beautiful foliage. I have never seen them bloom, but in photos, the flowers are lovely.
Q What are the white-flowering trees that are blooming right now? We have two in our yard in Bella Vista.
A The most common white-flowering tree that is in bloom now is a flowering pear. Many people collectively call all flowering pears "Bradford pear," but the Callery pear varieties have cross-pollinated, and seedling Callery pears have escaped and are blanketing our roadways and hillsides. In spite of their pretty white spring blooms and red fall foliage, these trees are not welcome: They have become highly invasive across the South.
Q I was walking by the creek on our place last Saturday and found this pretty foliage. My dad has been going there for several years and he says it's in the very same place every year when he looks for mushrooms. Can you identify it, please?
A The plant is an Italian arum. The foliage appears in cool weather in the shade. It will bloom soon with a white, spathe-like flower. After it blooms it can set a stalk of green berries, which will turn bright orange when ripe. Usually, by the time the berries are ripe, the foliage has disappeared, and gardeners find stalks of berries in their gardens with no foliage in sight. I get this question quite often.
Q I have sooty mold all over my "Lipan" crape myrtle. What is the best treatment and when is the best time to apply?
A The sooty mold can be there due to a heavy aphid population last season or the crape myrtle scale insect. Both insects suck sap out of the plant and give off a sweet substance called honeydew. Sooty mold grows on the honeydew. If your tree has the scale insect, you should see specks of white in with the sooty mold. If you don't see scale insects, then just wash off the stems and monitor this growing season. If you do see the scale insect, using a soft brush and warm soapy water, clean the stems. Then apply a systemic insecticide around the base of the plant. There are several products available. One application applied now through April should give you good control.
Retired after 38 years with the University of Arkansas Cooperative Extension Service, Janet Carson ranks among Arkansas' best known horticulture experts. Her blog is at arkansasonline.com/planitjanet. Write to her at P.O. Box 2221, Little Rock, AR 72203 or email
jcarson@arkansasonline.com
Style on 03/21/2020