Published on 02/19/04

Scientist forces hydrangeas into spring market

By Brad Haire
University of Georgia

A University of Georgia scientist wants to see hydrangeas in bloom sit proudly beside showy spring plants in garden centers each year. So he's giving them an early-winter wake-up call.

Hydrangeas have been faithful, shade-loving summer friends to Georgia gardeners for a long time. But they often flower too late to entice eager spring plant buyers, said Jim Midcap, a horticulturist with the UGA Extension Service.

Nursery-grown hydrangeas generally don't bloom until June.

"Most gardeners make their purchasing choices for the year in March, April or early May," Midcap said. "They miss seeing the hydrangea in bloom."

Wake up!

Midcap is working to see if nursery hydrangeas can be forced to bloom earlier and meet that early-spring consumer demand for big blooms and bright color. So far, the plants in his study seem willing to come out of their winter dormancy earlier with the right conditions.

Midcap began placing hydrangeas from outside plots into greenhouses in mid-January last year. He continued every two weeks until the end of February. The greenhouses gave the hydrangeas the heat and protection they wanted to break their winter dormancy.

He was looking for the best time to bring the hydrangeas in to force them to produce blooms by April 15. This date is considered the last day of possible frost for much of Georgia. And it falls in the middle of that spring plant-buying frenzy.

Nursery growers in Georgia could use the method to reach the earlier spring market and get premium prices for hydrangeas, Midcap said.

"And consumers will be able to see how the hydrangeas bloom and be able to put them in the garden at the best time: spring," he said.

Midcap repeated the study this year. He has about 1200 hydrangeas waking up in greenhouses now. They should have plenty of flowers around April 15.

Home gardeners with greenhouses could do the same with hydrangeas in their yards. Hydrangeas already in pots may do better than those you'll have to dig up and place in pots to bring into the greenhouse, he said.


Midcap used reflowering hydrangea cultivars for his study. Reflowering hydrangeas grow flower buds on new wood and are relatively new to the market. You should find them in most garden centers this year. Look for hydrangeas named Endless Summer and Penny Mac.

And if you haven't already, don't prune the hydrangeas in your garden now, he said, unless they're one of the reflowering varieties. You'll cut your flower buds off. If you do, you won't have as many flowers this summer.

Hydrangeas should be pruned in the summer soon after the year's flowering has stopped.

Brad Haire is the former news editor with the University of Georgia College of Agricultural and Environmental Sciences.