Do Asters Need to Be Pruned?
Asters do not strictly need to be pruned, but there are some good reasons to do it. One is simply to maintain a shape and size that you like. Especially if you have rich soil, these flowers will grow abundantly. Pruning them back can prevent the need to stake them and give the plants more pleasing shapes. Thinning them out will also keep your plants healthy and reduce the risk of mildew developing. Finally, by pruning asters, you will get a greater abundance of flowers throughout the growing season.
How to Prune an Aster Plant
There are several ways to prune perennials, but asters respond best to two strategies: thinning and pinching. Thinning is the best strategy to prevent mildew if this is a concern in your beds. To thin your aster, cut off entire stems at the base in the spring. About one in three stems is a good general rule for cutting back asters. Pinching is the aster plant pruning strategy to use if your main goal is to maximize the number of flowers you get from one plant. As the name of the technique suggests, all you need to do this is your fingers. You will pinch off the growing tips and the first sets of leaves on stems of the plant. Pinch them off just above the node for the best results. Pinch asters from midspring to early summer. Pinching promotes the growth of more blooms because it encourages more branching in the aster plant. The new growth on the top of a stem is the dominant one, and by removing that you encourage the side branches to grow by diverting more nutrients to them. Careful pinching and thinning is easy with asters and great for promoting healthy plants and abundant blooms. Deadheading spent blooms throughout the growing season can also promote additional flowering.
