August turns up all kinds of pests and disease in the garden. You may be noticing large webs across the terminal branches of your trees now, similar to stretched pantyhose. Look closely and you will see small caterpillars inside, each marked with parallel rows of black spots on the back. The fall webworm (Hyphantria cunea) is very noticeable now but at this stage, the caterpillars stay in the web and feed inside on the leaves. The web is unsightly but their feeding will not kill the tree. However, this would be a good time to cut the branches and bag the webs, caterpillars and all. Close up the bags tightly and dispose of in the trash. Later, after the last molt, they leave the web and crawl all over the tree. Then they spin cocoons, pupate, and emerge as white moths. If you are not able to bag the web don’t despair, there are many natural enemies of the fall webworm. Another tactic is to spray the first generation in the spring with horticultural oil, Bt (Bacillus thuringiensis), or insecticidal soap before they create the web. Don’t try to burn them out though, it is too dangerous to the tree. For more information on plant pests and diseases, check out the Plant Pests and Diseases tab on pegplant.com.
Pegplant’s Post Gardening Newsletter
Subscribe to Pegplant’s Post Gardening Newsletter, a free, monthly e-newsletter about gardening in the DC metro area. Each issue lists local gardening events, recently published books, articles, tips and news and always a giveaway. Just enter your e-mail in the subscribe box below.
Pegplant’s Post Monthly Newsletter
Join me on Saturday, December 17, 2:30 -3:30 pm, at the Fairfax County Oakton Library where I will be talking about Holiday Herbs and Spices. This presentation is free and in person; register with the Oakton branch here. If you are interested in having me speak to your organization, please contact me. I enjoy talking about culinary herbs, edible flowers, and holiday herbs and spices. We continue the conversation in the Facebook group Culinary Herbs and Spices.
- Bulb Companies
- Cooperative Extension
- Culinary Herbs and Spices Facebook Group
- Culinary Herbs Resources
- Demonstration Gardens
- Edible & Non-Edible Flowers
- Garden Clubs
- Local Books
- Local Nurseries and Plant Stores
- Master Gardener
- Monthly Events
- New Books: 2022
- Pegplant’s Post Gardening Newsletter
- Pests and Diseases
- Public Gardens
- Seed Companies
- Soil Tests
- Zones and Frost Dates