More recent landscape questions and answers

Horticulture

Diseased dogwood

After looking at the photos of dogwood diseases I think mine looks like dogwood anthracnose, a fungal disease. Some of the leaves are already turning red. What can I do?

The problem sounds like it could be dogwood anthracnose or some other foliar disease, however there are other problems that dogwood is susceptible to that can look similar. Certainly leaf scorch can look similar. Here in Missouri we are also seeing some early fall color and leaf drop on certain trees and shrubs. It may be due to plant stress, perhaps even related to the unprecedented spring freeze.

To be certain I suggest submitting a sample to the MU Plant Diagnostic Clinic or your local extension center.

Simeon Wright
Plant Diagnostic Clinic Coordinator

White spots on tomatoes

What causes my tomatoes to get white spots under the skin? Can they be eaten?

This is caused by stinkbugs feeding on the fruit. Stinkbugs have piercing and sucking mouthparts, so when they feed they suck the juices out of the tomato, leaving these white spots. They typically feed earlier in the year, with the damage showing up as the fruit ripens. It is edible, although some folks choose to trim out the spots before eating. To control the stinkbugs, they can be sprayed with an insecticide containing carbaryl or pyrethrin.

Timothy W. Horton
Regional Horticulture Specialist

Tall unknown plant

There is a six-foot-tall volunteer plant in my garden. The large leaves look a little like a sunflower's. It had tiny, yellow flowers with five petals. After the blooms, it had prickly, round pods. The pods had small seeds. I have photos. Can you identify the plant?

It can be very difficult to identify a plant from a description. I suggest submitting a sample or photo to the MU Plant Diagnostic Clinic. The plant diagnostic clinic identifies insects and plants as well as plant problems. You can see our Web site for more information.

Simeon Wright
Plant Diagnostic Clinic Coordinator

Activated charcoal and activated carbon

Is there a difference between activated charcoal and activated carbon used for terrariums?

Activated charcoal and activated carbon are different terms for the same material. The effectiveness of either would depend on particle size and surface area.

David H. Trinklein
Department of Horticulture

Barkless patches on hickory tree

One of my large hickory trees has barkless patches from the ground up to about seven feet. The dark brown areas have fairly deep vertical crevasses two- or three-inches-long. Although there have been thunderstorms in the past month, I see nothing else that would indicate lightning damage. I have digital photos. What can be the problem?

It sounds like your tree may have some internal decay. You might submit photos to the MU Plant Diagnostic Clinic.

Simeon Wright
Plant Diagnostic Clinic Coordinator