Pruning Mophead and Lacecap Hydrangeas

Apr 17, 2022 | Gardens

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. 

 

5 Comments

  1. Carol

    Thank you for this. Living and loving hydrangeas in Cape May NJ

    Reply
  2. Jan

    Wow! Your lacecaps are 2 different colors, love love love! Mine (“Endless Summer”, have 4 varieties) are always all blue… yes I know I could change to pink or purple but I tend to just let them stay blue as I have a number of oak trees so it’s a lot easier just to let nature take its course.
    BTW I am in the SE and Endless Summer mopheads down here don’t do nearly as well during the summer months as they do in the spring (the best) and then again in the fall (not as many blooms but at least they bloom again).
    I do deadhead to encourage blooms (except in October I stop to leave them on for the winter mths).
    I was told only water Hydrangea if after they are out of direct sunlight for an hour or so and the leaves are still drooping. If the leaves “spring back” then don’t water.
    One thing I have noticed is in summer if I don’t spray with neem oil solution weekly the leaves get yellow spotted with crispy edges. Looks awful!!!
    Any advice would be greatly appreciated 🙂

    Reply
    • CL Fornari

      Are these getting hit with an irrigation system? Hydrangeas are prone to leaf spot (which then turns the leaf yellow) when splashed frequently with water. They sometimes get powdery mildew as well, and that could cause what you’re seeing. The Neem would be acting as a fungicide, so if you think it’s PM, continue doing what you’re doing.

      Reply
  3. Terry Cox

    My mop heads are very floppy. How do I get them fill out?

    Reply
    • CL Fornari

      First of all, part of “stem sturdiness” is due to genetics of the plant. For example, Endless Summer isn’t very stem-sturdy, and when the flowers are large they often flop. Similarly, Annabelle flowers flop, but the variety Incrediball, in the same genus and species, do not…because Incrediball was chosen for having sturdier stems. So depending on which type of hydrangea you have and the variety, there may not be anything you can do to make them less floppy.

      That said, know that fertilizer makes plants grow faster and larger but does NOT make them stronger or stems more sturdy. Sometimes people add fertilizer thinking that this will help, but the opposite is true. Hydrangeas that are prone to weaker stems will be even more prone to flopping when fertilized.

      Reply

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