More recent landscape questions and answers

Horticulture

Bagworms

I noticed my spruces were looking very dry and as though the needles were burnt off in spots. When taking a closer look I noticed cocoons constructed of pine needles, about one to two inches long, some fatter than others. Upon breaking one of these cocoons open I saw a black worm. I was told these were budworms. However, the detailed information offered online was limited and the photos didn't look like my budworms. Could this have been a misdiagnosis? Is my description enough for you to make a good guess?

It sounds like your tree may have an infestation of bagworms. Please see G7250, The Bagworm in Missouri for more information.

Simeon Wright
Plant Diagnostic Clinic Coordinator

Barberry infestation

For the past three years my barberry shrubs have been infected with webs in the spring. The leaves die and fall off in the summer. What should be done to heal the shrubs and kill off the infectious pests?

Sometimes a severe infestation of spider mites can make a fine webbing around the leaves. Often, when the mite population gets this high, the leaves turn brown. I have seen barberries defoliated from drought stress during very hot dry conditions. Fortunately, they tend to recover when the drought is over.

If mites are the problem, you will need a magnifying glass to see them. If you look very closely, you will see them crawling around on the leaves. It is best to discover them before they have gotten established enough to make webbing, so keep a close watch next spring. You can control them pretty well by just spraying the plants with a hard stream of water once a day for about a week. Also, consider watering the shrubs during drought conditions.

Chris Starbuck
State Extension Specialist
Woody Ornamentals

Unusual oak tree

I have an unusual tree I suspect is a cross between a red oak and a white oak. This would be an atypical cross from what I understand. The tree was labeled Quercus palustris, but exhibits traits more like Quercus macrocarpa. How can I get a positive identification?

You are correct that white and red oaks would be unlikely to cross. I'm not sure what species it might be, but you would be welcome to submit a sample to the MU Plant Diagnostic Clinic. I suggest taking some digital photos and/or collecting a sample branch and submitting them to the clinic for identification.

Simeon Wright
Plant Diagnostic Clinic Coordinator

Caterpillars to butterflies

My children are intrigued by monarchs and other butterflies. Where are the best places to find caterpillars? How can I care for a caterpillar so that we can watch it turn into a butterfly?

Monarch caterpillars live solely on milkweed, so that would be a great place to find them. Wherever you find caterpillars of any kind, most likely they are feeding on their preferred food source. Therefore, clipping leaves of that plant to feed them is best. Leaves need to be cut daily, as they are nutritious for about 24 hours before they start to dry down too much for the caterpillar to feed on. Caterpillars need to keep feeding as they are developing, and once they are ready to pupate, they will stop feeding. At that time, you will no longer need to provide fresh leaves.

Mary K. Kroening
Horticulture Specialist

Raspberry yield down

I have about 300 square feet of raspberries in my garden. I've had excellent yields, 20 to 30 pounds, for about 10 years. This year I had very small berries and wilted plants, maybe one pound of berries. Should I tear out the plants and all the roots and plant new ones? Is it worth it to send digital photos?

Most likely a disease has affected your raspberries. For disease problems, it is often better to submit a sample, in this case affected cane and root material to the Plant Diagnostic Clinic for analysis and management information. You can find submission information and fees at our Web site.

Simeon Wright
Plant Diagnostic Clinic Coordinator

Horticulture

Bagworms

Barberry infestation

Unusual oak tree

Caterpillars to butterflies

Raspberry yield down

Questions and answers about vegetable growing