Gardening 101: Pruning Pt. 2

I know I skipped Gardening 101 last week so I will get back to it this week. You’ll have to wait until tomorrow to see photos of the trusty husband teaching the boy how to skip rocks. This week I want to talk about the timing of pruning.

Next to technique this is the most misunderstood concept in pruning. I always had people come to me in the nursery and ask why their tree/shrub hadn’t bloomed. The first question I asked was, “did you prune it?” Most of the time they said yes.

There are a few plants out there that timing depends on the variety. Clematis is one. There are 3 groups of Clematis and you prune them differently on the group. But you can look at Clematis as an example. As far as blooming plants go they do one of two things. They bloom on old wood or new wood. In this case wood can refer to branches or stems.

Case in point: Hydrangeas bloom on old wood. Butterfly bush blooms on new wood.

Many think that Hydrangea blooms on new wood. The bloom at the end of the summer (in our area) yet if you prune them in the spring they don’t bloom at all. This is because they set their flower buds immediately after blooming. So they have a short window in which you can prune them. Best bet is to do so just after their flowers fade.

Butterfly Bush blooms on new wood. You can whack it back to the ground in the fall and it will still bloom the next year.

To get a sense of what your plant does, watch it for a year. Don’t prune it at all in that year. If you see buds on the stems all winter long it blooms on old wood. If you see none it is likely that it blooms on new wood. The safest bet when pruning is to do it right after the blooms fade. Of course there are always exceptions to the rule. In that case ask a nursery professional or consult a book such as Pruning and Training put out by the American Horticulture Society.

Then there is the last of the rules. How many times have you gone out and pruned something in the fall to have it sprout new shoots and have those new shoots nipped by the first frost? It happens to the best of us. As a rule of thumb it is best not to prune after the 4th of July. Exceptions would be if you do summer pruning on fruit trees (whole different topic) or Hydrangeas. If you do prune after the 4th of July make sure you don’t do it until well into the fall/winter when the plant is dormant.

Like I’ve said, pruning is a difficult subject. It is over done and done wrong in most cases. My goal here isn’t explain every last detail of pruning, but rather to outline a few helpful hints. For more information refer to the above mentioned book.