Scale insect may be countered with pruning, or pesticides


Q. We moved from Indiana to Arkansas in February 2020. We learn about the different plants in our garden. I believe this is a hibiscus bush with a white styrofoam-like growth. What is it and what do I do to treat it?

A The plant in question belongs to the hibiscus family and is Althea or Rose-of-Sharon. In the picture, I think you have a scale insect – they don’t fly when you touch them, do they? I’m surprised you have such a good harvest this early as the leaves have only just appeared. Scale insects exude a waxy coating over their bodies to protect them from insecticides and predators. They attach themselves to leaves or stems and suck sap from the plant. If the damage is mostly to the tips of some branches, cut it out. Wrap up the cuttings and throw them in the trash. Insecticidal oils work before it gets too hot. A systemic insecticide like Orthene or Bayer Advanced Tree and Shrub will also work.

Q. Is that a bridal bouquet spirea? The leaves don’t look right. [The reader sent a photo.]

Viburnum opulus, an alien deciduous shrub, typically has rounder flowers; The weather blew it away. (Especially for the Democrat Gazette)

A You’re right, the leaves are way too big for a spirea. The plant in question is a viburnum – Viburnum opulus. The flowers should be more like a snowball shape, but recent heavy rains and winds may have damaged the flowers a little.

Q. Please identify this tree and the seed coat for me. Thank you very much! [The reader sent a photo.]

The post oak is monoecious with male and female flowers on the same tree. (Especially for the Democrat Gazette)

A The plant you have is a post oak – Quercus stellata, a species of oak very common in Arkansas. The little tassels you see are the spent male flowers called kittens. Oak trees are monoecious, which means they have male and female flowers on the same tree. The kittens are covered with pollen in spring. They hang down so the wind can pick up the pollen they produce and send it to all susceptible female flowers on the same tree or other nearby trees – covering our cars and houses with a greenish slime. The kittens release millions of pollen grains every spring. The fact that they are falling is a good sign that our allergy season may be nearing its end.

The post oak (Quercus stellata) produces male flowers called catkins.  (Especially for the Democrat Gazette)

The post oak (Quercus stellata) produces male flowers called catkins. (Especially for the Democrat Gazette)

Q. What is the best fertilizer for a new Zoysia shipyard? And how often should it be used?

A Greening turf grasses slowed down during the last cold spell, but grasses should be fully active in a week or two. Use a slow release fertilizer that is high in nitrogen (the first number on the fertilizer bag is nitrogen). Two applications can be used for a new lawn. Apply it first after the grass has fully grown, then reapply fertilizer in a month or two more. While some people fertilize monthly during the growing season, I think that’s too much and you end up mowing like crazy. One or two applications per season is all that is required. Here is a shortcut to an information sheet on growing Zoysia in Arkansas from the University of Arkansas Cooperative Extension Service:

Q. Recently you talked about pruning a damaged palm. When you say “remove the fronds,” are we also removing the long stems?

A Think of a palm frond as a compound leaf. The leaflets of the frond are attached to a petiole or stem. Remove all of the leaf from the leaflets to the stem where it is attached to the main stem. New foliage should appear at the top of the stem or trunk of the palm of your hand.

Janet Carson, who has retired after 38 years with the University of Arkansas Cooperative Extension Service, is one of the best known horticultural experts in Arkansas. Her blog is at Write to her at PO Box 2221, Little Rock, AR 72203, or by email