Old Wood vs New Wood
The first step to knowing the best time to prune hydrangeas is determining if they will bloom on old wood or new wood. Here’s the definition of each; we break down which is which below. (This is not as horticultural geeky as it sounds, we promise.)
“Old wood” means that buds are formed for next year’s bloom at the end of the current growing season on stems produced during the previous summer.
• Typically pruned after flowering or early fall to encourage new flower buds on old stems.
“New wood” means stems that have emerged during the current growing season. Buds are formed on this new growth in the current growing season.
• Typically pruned in late winter or in early spring to encourage new stems.
If you get the timing wrong, don’t worry. These are forgiving plants. You may go a season without blooms but, with proper timing, you can expect flowers the following year.