Extension Master Gardeners offer tips for protecting plants from the 17-year invasion of Brood X Cicadas
March 18, 2021
The 17-year Brood X Cicadas, also known as the Great Eastern Brood, will soon debut from their long underground life cycle stage between late April and continue into June.
Virginia Cooperative Extension Agriculture Agent Kirsten Ann Conrad says it’s important to plan accordingly to protect your trees and gardens from the 6 week life span of these annoying arthropods. During mating, male cicadas will fill the air with their mating songs. Afterwards, females will cut slits in tree branches to lay clutches of about 25 eggs, producing up to 400–600 total.
“Young, newly planted trees can be vulnerable to severe damage from periodical cicadas and should not be planted this year until the fall,” says Conrad. “Egg laying activity can result in the death of tree branches that are ¼” to ½” in diameter. Insecticides are not particularly effective and not recommended as many birds and animals feed on the cicada larva and adults.”
The Great Eastern Brood of cicadas will emerge in areas of NY, NJ, PA, DE, MD, DC, VA, WV, NC, GA, TN, KE, OH, IN, IL, and MI in 2021. For 2-3 weeks in late spring, adult cicadas will emerge at sunset from their underground locations where they spend most of their lives one to eight feet below the surface as nymphs feeding on sap of tree roots.
Conrad offers the following tips for how to protect plants and trees from their above ground egg laying activities.
- Avoid planting young trees within 1-2 years before an expected emergence of periodical cicada.
- Use netting to protect young trees and fasten securely to prevent birds and other animals from getting stuck. Netting with a mesh no larger than ¼ “ (.5 cm) will effectively control injury on branches. Make sure that it is kept tied well enough to exclude mammals and birds from being trapped. Remove netting by July 1 or so.
- Tree wrapping with paper tape, spun bond fabric or similar materials can deter egg laying.
- Birds and many animals will feed on cicadas but the explosion of the cicada population does not favor effective biological control.
- Insecticides are not recommended.
- Dead branch tips can be pruned away and discarded to reduce egg hatch in your landscape.
- Make sure to keep your tree healthy. Provide 1 inch of water per week, stake it as needed for up to one year. Remove turf and other ground covers from around tree to reduce competition for water. Make sure you have chosen and planted your tree species correctly on your site.
- Newly emerged cicadas are edible (by humans too) before their shells harden up and many recipes can be found online.
To learn more, join Kirsten Conrad and the Master Gardeners of Northern Virginia on March 26 at 10 a.m. for a free Zoom discussion to learn about the life cycle of cicadas and how to protect plants and prepare gardens for the 17-year brood. RSVP here.
Kirsten Ann Conrad is an agriculture natural resource agent with the Virginia Cooperative Extension, which is an educational outreach program of Virginia's land-grant universities: Virginia Tech and Virginia State University, and a part of the National Institute for Food and Agriculture, an agency of the United States Department of Agriculture. The program strives to improve the well-being of Virginians and increase producers' profitability through programs that help put research-based knowledge to work in people's lives.
To secure an interview with Conrad, contact Shannon Andrea in the media relations office at firstname.lastname@example.org or 703-399-9494.