Q I think I remember that a couple of years ago you had an article on how to wash the black off stalks/trunks. Would you please reprint it since I have a crape myrtle with black stalks/trunks? I have two crape myrtles, one is beautiful and the other isn't since it is black.
A Black stems mean you had a problem with a sucking insect this past season that gave off a sticky substance known as honeydew. Wherever honeydew lands, a black sooty mold will form. It can occur on the trunks and branches of your crape myrtle, but also on your patio furniture and your car. You can clean it with a soft brush with warm, soapy water. One man used his pressure washer to clean the trunks. You can clean it but the black will come back unless you solve the insect problem. Two insects could be the culprit — aphids and the crape myrtle bark scale. Aphids are insects that can build up in the summer and cause a problem on crape myrtles, and often they cause the foliage to turn black. When I see black trunks, I usually suspect the crape myrtle bark scale insect. This insect has only been with us for 4-5 years but has spread across our state. If the tree has scale, you also should be seeing specks of white on the trunks. Here is a link to a publication with pictures that will give you more information: arkansasonline.com/420scale.
Q I am thinking of planting elephant ears in the backyard, but I heard they are very invasive. Are there any types that are not invasive?
A In tropical regions there is a smaller leafed form of elephant ear commonly called wild taro that can spread prolifically and is considered invasive. There are several different plants that have the common name elephant ears, and some are more prolific than others. Alocasia, Colocasia, Xanthosoma and some hybrids all bear the common name elephant ear. There are clumping forms and running forms. Winter hardiness can also vary by species and where you live in Arkansas. Avoid the running forms, which can spread from stolons and multiply more easily. The number of selections today can boggle the mind, and prices can too. Read the information on any variety you are buying to determine how winter hardy it is, and its growth habit.
Q Can you help me identify this fungus-like growth on a tree in our yard? [The reader sent a photo.] What should we do about it?
A In the spring sap is rising. When you have an open wound on a trunk, the sap will come out. Sap is sweet, and fungal organisms can grow on it. You have a yeast organism that is taking advantage of a free meal. Some of these yeast organisms have an orange pigment. They grow well where there is plenty of sugar. They also can be somewhat mucusy in appearance. Once the sap quits rising, eventually the bleeding of sap will stop. You can hose off the offending substance. Hopefully the wound can callous over in time.
Q This ficus is 5 1/2 feet tall, about 20 years old and has outgrown its space [the reader sent a photo]. I repotted it about two months ago and pruned the roots heavily. It has recovered from the shock and is growing nicely. Please advise how to prune. I don't want a pompom appearance.
A A pompom appearance is usually the result of shearing the plant. Instead of a general shearing, selectively remove a few branches here and there. Once you do that, decide if any more growth needs to come off. From what I can see, it looks great where it is. Root pruning often limits the amount of top growth, too.
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
HomeStyle on 04/20/2019