GOLDEN VALLEY, Minn. — Hydrangeas are a fan favorite around here.
Knowing when, how and if to prune them will have them looking their best year after year - of which there are a couple rules to remember.
If your hydrangea is just blooming now in late summer, put it in your calendar to prune it in late winter or early spring. This includes Limelight, Quickfire, Burgundy Lace and Annabelle, which is the classic "snowball" type. PeeGee hydrangeas which produces creamy white flowers in late summer that age to rosy pink are also in the is category. These varieties bloom on new wood, meaning the blooms come on stems that grow new each year.
Other hydrangeas bloom on what is called “old wood”, meaning the buds for next year’s flowers are set on the growth that happens this season. This includes oakleaf and bigleaf hydrangeas, lacecaps climbing and all varieties that bloom blue or pink like endless summer and summer crush among others. You should prune these types before August…so not any more this year.
But unless you need to control the size or shape of your hydrangea, you don’t NEED to prune at all.
If you do prune, cutting out the oldest, biggest canes will help to control the size and can reinvigorate the shrub.
To get bigger flowers, you can cut them all the way back to the ground. But also consider that leaving some stems 18” to 24” high can help reduce flopping next year.