If you’ve seen photos of my garden on Facebook and Instagram, you’ll know I harvest and display my hydrangeas throughout September and October.
Hydrangea harvest is as easy as snipping off a bit of stem with the now partially dried flower head and showcasing the blooms in vases, floating them in bird baths or, my personal favorite, poking the stems of cut blooms into container gardens. This way to display hydrangeas will fill in the bare spots from summer weary annuals.
Step away from the loppers and other heavy pruning tools. October is not the time to do serious or heavy pruning of hydrangeas, forsythias, rhododendrons or any other shrub. Winter is coming, and pruning always stimulates growth — fall is when you want shrubs to slip into winter dormancy.
Harvesting hydrangea blooms and cutting back perennials is the exception to the rule when it comes to no fall pruning.
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How to dry hydrangeas
Start cutting the blooms in August and up until October when the petals feel leathery but are no so old that they are turning brown.
Place the cut stem into a vase with one inch of water. As the water evaporates, the hydrangea bloom will continue to dry.
The other harvesting tip is to keep the cut blooms out of the direct sun and heavy rain. This makes a covered porch or patio the perfect spot to display cut hydrangeas. You won’t even need a vase or wreath to display your hydrangeas if you poke the cut end of the stem into moist potting soil.
How to start new hydrangeas
As a bountiful bonus the hydrangeas you harvest might root if you poke them into soil this time of year.
Just remove the lowest leaves from a cutting 8 to 12 inches long. Poke the bottom half of the cut branch into moist soil where it will be protected from the winter freeze.
In the spring, when you go to clean up your container gardens, you might find that a stem or two has taken root over the winter. At this point snip off the dried flower head and in a few years the rooted branch will be mature enough to flower again.
You can transplant the rooted cutting into the garden in early summer or leave it in the container for a few years.
When to prune hydrangeas
The simple answer is to wait until spring if you need to prune back a hydrangea shrub.
Harvesting the blooms is a form of pruning, but the mophead hydrangeas with the big round blooms (hydrangea macrophylla) is the most common variety, and these flower on 2-year-old wood. So the branches that bloomed this summer, that you harvest in the fall, will not flower next year.
This is why it’s OK to cut the branches in October. There are always exceptions — Endless Summer hydrangeas flowers on both old and new wood. Just wait until spring to prune these as well.
Happy hydrangeas might never need pruning
Giving your hydrangea shrub plenty of room is the key to less work and more blooms. Hydrangeas are happiest if you don’t prune them at all. They want to grow into huge shrubs filled with blooms.
Here are two exceptions:
Pee Gee hydrangeas (hydrangea paniculata). This variety has pointed flowers that start out cream and then turn pink and russet. It can be pruned into a tree or standard shape with a central trunk.
Prune this variety in early spring or late winter when you see the crocus in flower. Cut out thin branches and shorten long branches by one half.
The fewer branches on a Pee Gee hydrangea, the larger the flowers will be. This hydrangea does best in full sun but will tolerate half a day of sun.
Smooth hydrangeas (hydrangea arborescens). The foliage is less serrated or jagged and these very cold hardy hydrangeas have stronger stems and larger blooms than the traditional mophead hydrangeas.
Examples are the Annabelle, Incrediball and the Invincibelle Spirit hydrangeas. These all flower on new wood.
Cut the stems back to just one to two feet tall in early spring. This gives the shrub shorter, stronger stems to support the huge blooms.
The smooth hydrangeas will take full sun and freezing winters so they are becoming popular as flowering hedges and as shrubs to use in large containers.