Since I was fortunate and did not get flooded last week I spent a few days pruning my hydrangeas…second only to my roses in that they “must be done,” and following the spring-blooming clematis – discussed in my last post – which has to be first according to the calendar. But, you may say, “Aren’t hydrangeas supposed to be pruned in the fall after blooms fade”? Well, no, they can be pruned either in the fall or in the spring…I prefer spring, so let me explain.
There is no advantage to pruning in the fall because you will have to prune again in the spring anyway. Why? Because parts of the plant will be damaged or killed by winter weather and these parts have to be removed. So you might as well do all pruning at one time. Now I originally thought hydrangeas were the easiest of all plants to prune because you can cut to them any height and there is no “shape” to worry about. I soon found out that it is quite the opposite and while I prune the plants with loving care each spring I struggle and swear while I am working. The reason they are so hard to work on is two-fold: when you remove dead branches you have to cut them at ground level and when you work around the budding stems you knock off the buds!
Here are some guidelines that may help you with this task. First, wait until you see the buds starting to swell so the dead ones are obvious. Then, cut out all dead stems, stems that are rubbing against other stems, and stems that look like snakes twisting and turning in all directions. Now you can cut back the
remaining branches and this is where some informed decisions have to be made. Endless Summer hydrangeas produce blooms on both old and new wood. This means you can cut the stems as much as you want without losing a bloom cycle for the season. If, however, you have an “old fashion” hydrangea, such as a Nikko or lace cap variety, care must be taken because if too much stem is cut off the flower buds will be removed and there will be no bloom until next year. I like to keep my hydrangeas at the same height every year so I cut about 6 to 8 inches off the tops of all stems, which is the amount of seasonal growth and the plants will always stay the same height. When you cut the stem back, always cut just above a pair of healthy, swelling buds.
There is one footnote to all of this. Endless Summer hydrangeas do not have cold-hardy flower buds, so if the winter was severe they may be killed and you will only have blooms on whatever new branches grow this season.
The third part of my pruning series will talk about roses, so check back next week.