GADENING: To prune, or not to prune?

Allow me to elaborate. Many years ago, my colleague and great friend and Director of Secrest Arboretum in Wooster, OH, did some hard pruning on a boxwood hedge in the arboretum. These boxwoods were about four feet tall, and he pruned them back to around two feet tall.

He did this in November. He also knew that he was taking a great chance. It proved to be a bad choice, his words.

When you prune during this time of the year, you risk cold damage to the plants. The very act of pruning is wounding a plant. Pruning branches back exposes the stems and thus plant tissues to cold damage.

In this example, there was an extreme drop in temperature in December and the exposed tissue was significantly damaged. The next season, almost all the growth was dead.

Therefore, typically we wait until February or March to prune woody plants. If you have perennials, they can be cut back at any time.

If you are on social media, you have probably seen information on leaving your perennials up for overwintering native bees and other insects. It’s a good theory overall, however, it’s not always possible to do this.

Many of our native bee species use the hollow stems of woody plants to create their homes. The idea is to leave these stems alone and prune them back next season. These stems will become homes for next season’s native bee populations.

The challenge is that if you have a rather large garden, you may not be able to do all the necessary work in the spring. In addition, if you are a commercial landscape business, many other things need to be done in the spring, and this may not be feasible.

So, how can you work around these challenges? I cut almost all my perennials back that have no winter interest. This includes those with woody stems. However, I leave several stems of certain plants (coneflower, rudbeckia) to provide for bee nesting.

I cut any plants that look bad or have turned to mush, such as Hosta, in the fall. However, I also leave them if they look good. You would be surprised at how many Hosta varieties have a beautiful golden fall color.

Social media posts frustrate me because many times they aren’t based on science. Learning about the life cycles of the native bees, I was able to make an educated decision about what to do in the garden while still promoting the overall population and health of pollinators.

And of course, sometimes plain common sense must prevail. If you have a commercial business, it’s great to help the pollinators, but you also have a bottom line and employees to take care of. It’s a balance, in my opinion.

There are a variety of perennials that still look good, especially this fall because of the extended warm weather. I have even seen annuals in full bloom this fall.

Credit: Contributed

Credit: Contributed