How To Prune Asters

You can prune and pinch the flowers of asters to increase growth and the number of buds. Pinching new growth will force the plant to feed the lower stems and grow fuller. This forced growth will develop a stronger plant with more flowers. Pruning can help develop the plant into the size and shape you want.

Pruning Seasons

Pruning is a more drastic approach to improve the plant's growth. Asters can be pruned as often as three times a year. As new shoots start growing, most of the plant's resources will be sent to the new stems. This will reduce the growth to the lower parts of the plant. The best time to prune is after they have flowered. You can prune in early June. The second pruning may be done later July after the second flowering.

At the end of the growing season, trim the plant to leave just an inch or two above the soil and cover it with mulch to protect the plant through the winter cold. This will allow the plant to grow again the next growing season. With pinching and pruning, you can develop your aster into the shape and size you desire.