What is the best time of the year to prune hydrangeas in order get the most blooms for the next spring and summer growing season?
Multnomah County Oregon
Thank you for choosing Ask an Expert for help with your hydrangea. For the best flower show, the most important thing is to maintain a healthy plant—good drainage, consistent watering, fertilizer, etc.
Then, these tips are for the most common hydrangeas—mopheads and lacecaps. Other types will have different methods.
First, deadheading—not really pruning. After the blooms have dried and are no longer attractive, clip them off just above the first or second set of leaves below the bloom. This is where next year’s flowers will form, so you don’t want to cut them off.
True pruning. Hydrangeas don’t need much pruning. But, if the shrub has an abundance of shoots and the interior is crowded, thinning is helpful. Look for the older, woody stems, thin, spindly, weak stems, or any dead ones. Take them out at the base. This will encourage new shoots to form, refreshing the plant. Generally, this is done in June or early July, before flower buds have been set for next year, but now is fine.
Good luck with this Northwest favorite,
They get so big, I need to prune them or they will crowd everything out. The plants next to them are at least 5 feet away.
You can certainly prune them down quite a bit if needed later this fall, just be aware that they may not have very many if any blooms next year. I just had to do this in my own yard as they had not been maintained for many years before we moved in and were easily taller than they average person in width and height. They only had a few blooms, but are much more manageable to trim down for next year.