Pruning Mophead and Lacecap Hydrangeas
I pruned one of my lacecap hydrangeas yesterday. It’s been a warm April – especially for Cape Cod – and one of my shrubs had leaves opening so that I could clearly tell which buds made it through the winter and which ones did not. The way to prune both mophead (Hydrangea macrophylla) and lacecap (Hydrangea serrata or macrophylla) Hydrangeas is to only remove dead wood. You cut off the tops of stems that have died, and any other cane that has no green growth on it, but you never cut them down to “neaten them up” or try and make them shorter. These plants replace their height in one season, and the more you cut off of them, the fewer flowers you have. If you want hydrangea blooms from top to bottom, never cut them shorter.
Many of the Hydrangeas in my yard aren’t at the pruning stage yet. When the buds are still dark, or just beginning to show green, it’s hard to tell which canes should be cut. If you prune such shrubs too early you’re likely to remove future flowers by mistake, or have to go back and prune again once the plant is solidly past breaking dormancy. But if your plant has opening leaves as pictured below, it’s time to clean them up for the summer. Use the following method:
Once the leaves start to open on your mophead and lacecap Hydrangeas, it’s time to prune them.
Here is how this lacecap looked before I started pruning. It was filled with the remains of last year’s flowers, had a few stems that stuck into the walkway, and a few canes that are completely dead.
Do not be tempted to just chop off the top of your shrub with hedge trimmers! You will be removing a number of future flowers if you do so. Instead, go slowly, stem by stem, cutting off the top dead parts just above the first set of green leaves you come to. Yes, it takes time. Enjoy the process! It’s a spring meditation.
After pruning, this is what remains. I took off three canes that were coming forward over the path, but otherwise just removed deadwood. You will see that I did not cut the plant to below the window. If I had done so, I would see the plant grow just as tall this summer but with a dome of green leaves instead of flowers on top. Don’t attempt to control the height on Hydrangea macrophylla and Hydrangea serrata varieties.
And why would I want this plant to be shorter? As it is, I can enjoy these beautiful lacecap flowers from the outside or from my kitchen. I can stand indoors and look out the window at the bees that dance on the fertile parts of the lacecap blossom.
If you would like to print out a “how to prune blue hydrangeas” handout, download one here.