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ShouldI cover my hydrangeas this week? #926090

Asked March 16, 2026, 10:41 AM EDT

Hi extension, I had terrible luck with my hydrangeas last year. Most of them didn’t bloom due to a late freeze. They were beautiful two years ago, but nonexistent last summer. My plants have these green buds on them right now ( see pic). Should I cover them this week when the temperatures go below freezing? Also, if I need to cover them, what would be the best material to use? I have some moving blankets but fear that would be too heavy. I am a beginner gardener and kind of clueless about this stuff. Many thanks!

Prince George's County Maryland

Expert Response

Hi, 

It would probably be helpful to protect them. Moving blankets are likely too heavy unless you can prop them on stakes around the plants. You can search in home improvement stores or agriculture-type stores for frost cover, which is like row cover that vegetable gardens use to help protect plants and extend the growing season. It is a white, somewhat transplant material. (The link will show you photos and explain in more detail.) You may not have time to order it online, unless you can find a quick delivery time. Old sheets can work as well. You could also try a plastic tarp and just remove it after the cold nights have passed. You don't want to leave sheets or a tarp on too long, though, since they will restrict light to the plant. 

Fingers crossed for protected buds! 

Emily

Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied March 16, 2026, 11:13 AM EDT

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