QWe have a Bradford pear tree that is looking bad. It has had a number of black leaves forming in the last two weeks, and some branches have fewer green leaves. It was planted in spring 1998. I think it is dying. Is there anything I could do to help save it, or is it on its last days? The spring blossoms were normal -- loaded and beautiful.
AWhile you probably know that Bradford pears are not my favorite plant, there are many gardeners who love them. It sounds like your tree was hit by fire blight. By now the damage that is done is done. It typically stops spreading when the temperatures rise. The tree gets infected during bloom. Prune out the damaged branches, and if there is a lot of dead wood, you might consider replacing it with a better tree species. No sprays would give any control this late in the year.
QI've just noticed that I have a disease or infestation on new growth in my boxwood hedge. It is all white, and at the moment seems to be on the stems only. Leaves do not appear to be affected at this time. It looks and feels like baking soda or talcum powder. If possible, tell me what it is and what would be my course for combating this invasion.
AWe have received reports from all over the state about this white powdery substance that moves. Early on we did have woolly aphids, but now we seem to have more flatid planthopper insects. While the immature nymph does closely resemble a white woolly aphid, and this planthopper excretes honeydew as aphids do, it is a different insect. They feed in much the same way, but planthoppers move quickly when disturbed and often jump or hop for several inches, whereas woolly aphids are more sedentary. Normally planthoppers like these are not found in numbers that require attention. But if you have a heavy infestation, the pesticides labeled for aphids will give adequate control of flatid planthoppers -- insecticidal soap, Orthene or Malathion. Or you can blast them with a strong spray of water. Their damage looks worse than it is, so don't be alarmed.
QI recently pruned a large holly back from 10 feet to about 6 feet. There was a lot of dead wood inside but the outer portions have always looked very healthy. It has been about 10 days now and still no sign of new growth. I probably pruned later than I should have. Should I be concerned?
ABe patient. Plants typically don't grow in leaps and bounds when it is hot and dry. That is why we recommend doing severe pruning in late winter to early spring to catch the natural rebound of new growth. For now, water, water, water and wait for the growth to come back.
QCould you send me the info on the "white" mold that is on the crape myrtles this year? I know you wrote about it earlier this spring. What is the treatment, if any?
ASince you are in Bella Vista I would guess you have powdery mildew, a white powdery substance that covers the leaves, and not the white felt scale that those of us who live in central Arkansas are seeing everywhere, and which gets on the branches and trunk. I have seen some trees heavily covered in the powdery mildew, so it is bad this year. Use a general fungicide such as Daconil. The mildew will be difficult to eradicate, but you can slow it down. If you have a tree that gets hit every year, a preventive spray may help, but if this was an isolated incident, use good sanitation this fall and see what happens next spring.
DEAR READERS: Want to learn more about invasive plants and how to identify and control them? Arkansas Master Gardeners will conduct an invasive plant workshop 9 a.m. to 3 p.m. July 19 in the Magnolia Room at Garvan Woodland Gardens in Hot Springs. The cost is $30 ($15 for the gardens' members), which includes snacks during registration, but not lunch. (There is a cafe on site.) Pre-registration is required; call (800) 366-4664 or register online at bit.ly/29aBMhv.
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 07/09/2016