Thinking about hydrangea pruning in later winter? I know we all get itchy fingers about now, but take a deep breath and step back.
Pruning Advice for Cold Climates
If it is late winter where you are and the footing is safe, you can do some hydrangea pruning now. BUT, if you are in colder zones, e.g., 5 and below, I would suggest you wait. Mother Nature isn’t finished with us yet and March can be a very cruel month. If you prune too early, more winter kill can take your plants down even further than the early cuts you make.
Pruning Advice for Warm Climates
On the other hand, if you are in the Southeast U.S., the Pacific Northwest, and other relatively mild places, you could get a jump on late winter hydrangea pruning tasks. However, only go after woodland/smooth hydrangeas and panicle hydrangeas. Period. That’s because they flower on the growth they will put on in the next few months (new wood). So there is no danger of cutting off the flower buds. Exactly which hydrangeas are they?
New Wood Panicle Hydrangeas
Panicle hydrangeas (paniculata) are the ones that bloom on new wood all the time. By name, panicle hydrangeas could be ‘Limelight,’ Pinky Winky, Strawberry Sundae, etc. In short, they are hydrangeas that love the sun. Their flowers are cone- or football-shaped and can be white, green, and shades of pink (never blue), especially as they age. Some can be as small as 18” tall while others can be gigantic 8 footers.
New Wood Smooth Hydrangeas
The other new wood hydrangeas (arborescens) are woodland/smooth hydrangeas. They might be called ‘Annabelle,’ Incrediball, Haas’ Halo, etc. They also bloom on this year’s growth and can be found in semi-shaded and/or sunny sites. Their flowers are distinctively big round puffs of either green, white, or shades of pink (never blue).
How To Prune A Panicle Hydrangea
Prune your panicle in late winter the same as you would later on. First, you can remove any stems that are dead, diseased, or damaged. Also look for stems that are growing inward or crossing/rubbing against other stems. Unmanaged, that will leave you with a damaged stem that can be a gateway for insects and disease later on.
After that, you can simply deadhead your plant and let the rest go. But if you need to control growth to some extent, then the plant can be taken down by about one third, generally speaking. Unless you have a new plant that is barely 2 feet tall. Then the thing to do is just take off the tip, including any spent flowers.
But remember my earlier caution. If you live in a cold climate, leave the plant alone. There’s still a lot of winter left and you want to allow for winter kill. Wait a few more weeks. Gardeners in zones 7 and warmer could take a chance and start now. Just remember there is always the possibility of late winter cold snaps which could knock your plants back.
How To Prune A Woodland Hydrangea
Just as with the any plant, late winter hydrangea pruning is no different than the steps you would take later on. Start by removing the dead, diseased, and damaged wood. Do the same “opening up” task described for panicle hydrangeas and remove crossing and inward growing branches. You may even want to take out several stems at the ground level to reduce the overall size of your plant. My preference, however, is to dig out those ground level stems and start new plants somewhere else or give them away. They transplant wonderfully as long as you capture a good handful of roots.
Do Not Cut Your Woodland Hydrangeas Down To The Ground
No matter what you read on the internet, do NOT cut your woodland hydrangeas to the ground – EVER. When you do that, you encourage new stems that will not be strong enough to hold their later season flowers. Instead, leave several stems up at about 30 inches to help form a supportive framework for your plant.
What About Big Leaf (macrophylla) and Mountain Hydrangeas (serrata)?
Your big leaf hydrangeas flower on old wood. Some can produce flowers on new wood (e.g., ‘Endless Summer’) as well. If you know for certain that your plant flowers only on old wood (e.g., ‘Nikko Blue,’ Cityline, etc.), you could take care of the dead, diseased, and damaged stems. You could also go after the old wood that won’t give you flowers. But as mentioned earlier, I would leave them alone for now. Again, you want to let ol’ man winter do his thing before you work on them.
Pruning advice for mountain hydrangeas (serrata) is the same as above for big leaf.
Other Old Wood Hydrangeas
The other hydrangeas you may have like oak leaf (quercifolia) and climbing (petiolaris/schizophragma) flower only on old wood. Follow the same advice for late winter pruning as above for them for now. Leave them alone until you are past your last frost date.
For a more detailed discussion on hydrangea pruning, go HERE to a post I wrote in March of 2020. Ignore the last section on “Upcoming Talks.” They are totally irrelevant.
Upcoming Public Talks/Presentations
This is a new year and I am continuing to book talks, both virtual and live (HOORAY!!!). If you are interested in having me speak to your group, just click HERE and you will be taken to the “Contact Me” page of my site to begin our dialogue. I cover lots of other topics besides hydrangeas, as you will see when you click on “Speaking Topics.” All my talks are 5-star rated, so you won’t be disappointed.
Here are two public presentations that may interest you:
Feb 20, 11 a.m.: Success With Hydrangeas, The Southeastern Connecticut Home and Garden Show. Format: In person. Cost: Free with admission to the show which is a fun day out.
March 12, 10.30-12.30, Weatherproof Hydrangeas, New York Botanical Garden. Format: Virtual. Cost: Member – $55; Non-member – $59.
I will also be at the upcoming Connecticut Flower and Garden Show in Hartford, CT on Thursday, Feb 24 and Friday, Feb 25. On Thursday, I will be helping out at the Connecticut Gardener (a fabulous magazine) table. Friday you can find me in the morning at the UConn Home & Garden table, answering gardening questions.
I look forward to seeing you. Tell/bring your friends
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