Trimming Asters

I've noticed on my stat reports that quite a few people have viewed my blog while searching for, no -not for the mysterious killing squirrels in the rain*, but for trimming asters and pruning asters. I've discussed more than once pruning asters in June, but never mentioned what to do with them come November. I wouldn't want anybody to leave empty-handed, so what can be done now that most asters have quit blooming?

You do not need to cut the asters back until late winter/early spring. But you may prune back the dry stems now if you prefer the neater look of cut perennials. Just cut them a few inches above the ground. There are many types of asters, of course, but all may be cut back after flowering is over. New England and New York Asters and their cultivated counterparts will form clumps which may eventually need to be divided. You can do this in spring. Plants such as the Smooth Aster will form fluffy seed heads that will self-seed whichever way the wind blows. If pulling asters in spring is not your style, cut those back before they go to seed. By the looks of my asters, now is entirely too late!

*actual search that somehow landed here.

Trimming Your Aster

I learned awhile back about clipping asters from a neighbor who's own always seemed to be completely under her control. I wouldn't have ever known if I hadn't spied her cutting them. 

Each year the time to consider clipping might be different. This year, it's quite early. I've clipped my taller asters, those above 16 inches, back to about 13-14 inches. No matter the height, consider reducing clipping back by 15-20 percent. Doing this will promote more flowering, as clipping can with so many plants, because you cut the dominant growth tips (apical meristem), allowing many side stems to grow. Aside from bushier plants with more flowering buds, it also keeps the plants a bit shorter, and less likely to flop as far when heavy with flowers in the fall.

You can be graceful or rough about the clipping. I tend toward the middle.

All the asters that are quick to get tall get this treatment. This includes the New England asters, the perennial sunflowers, and even goldenrod -Solidago.

This aster, at 8 inches tall, isn't grown enough for clipping. Maybe in late May or early June. Here in New York City, I wouldn't clip after late June. At that late date, you will weaken the plant, invite disease, and limit formation of flowering buds. So to be safe, clip early when the plant reaches 16 inches or more.