Netting won't hurt the plants, but remove it as soon as the cicadas leaf next month. Also be sure seams are tight so no cicadas gets trapped inside the netting, which will cause it to lay eggs on every branch it can reach. 

Here is more about cicadas and netting: https://extension.umd.edu/resource/cicadas

Ellen

That's a typo: "as soon as the cicadas leave."

Cicadas will be here till about mid-June.  They will gradually leave.  There is not specific date, of course.  You'll notice less of their singing and less activity.  Take off the netting then. 

Ellen



That is an interesting question. We asked the cicada specialists in our UMD Entomology Department about the timing. Research literature indicates that the female cicadas typically mate once while males are thought to mate several times. Since the males have more opportunities to mate they might continue to sing until they find no more available females, and once mated, the females will seek out branches to lay eggs in, so at some point, both sexes will peter out. The Cicada Mania website is a great resource for questions and answers based on data from past observations of Brood X (and other broods). Their periodical cicada emergence timeline shows that singing may continue for about a week after mating and egg-laying occurs. https://www.cicadamania.com/cicadas/periodical-cicada-brood-x-10-will-emerge-in-15-states-in-2021/

Christa

Hello Gail,

Cicadas target trees, so shrubs like Oakleaf Hydrangea are not their preference for egg-laying. However, since they may indiscriminately try to lay eggs in other woody plants due to their sheer numbers, it's not impossible that some would attempt to use the Hydrangea. Even so, shrubs overall recuperate from such damage much more easily than a young tree. Since Oakleaf Hydrangea is fairly slow-growing compared to other shrubs, you can always cover them if you want to avoid any potential setbacks. Otherwise, netting them may not be worth the trouble; it's a personal choice of risk assessment.

Miri