So you’ve planted asters in your garden landscape, now what?
If the aster variety you’ve chosen reaches four feet in height or more, it will require staking. New York and New England aster varieties typically require staking or support unless they are dwarf varieties.
Grow-through support hoops with long legs work well for staking tall, bushy perennials like asters. The grow-through supports must be placed over the plants in the spring to allow ample time for the stems of the plant to grow through the support.
Pinching or cutting back asters throughout the spring and early summer growing season can eliminate the need for staking. Pruning shears or hedge clippers should be used to cut off four to six inches of growth at one time.
In the Ozarks, asters can usually be cut back a couple of times. I like to cut mine back once in May and again in late June or early July. Both times, I try to reduce the plants’ height to 18 to 24 inches. When pruned, a four-foot tall plant will only reach 24 to 30 inches in height, and they typically will not fall over at that height.
If you wish to delay flowering of asters in Ozarks (which usually starts in mid-September), cut the tops off the plant again late July. The result will be asters that begin blooming about Oct. 1.
Asters should be divided when the center of the plant becomes bare. Divide the aster plant by simply using a spade or hand trowel to cut into the side portion of the plant. These clumps can be divided and replanted. Aster division is best done in early spring or fall.
Asters can suffer from foliar diseases such as powdery mildew or rust. These diseases are usually the result of poor air circulation between the plants. Thinning of the plants can help with circulation issues. The application of fungicide about July 1 can also help stop the spread of disease.
Blossoms on asters will persist even after several frosts. The plants can also provide attractive winter interest. Gardeners should be aware that leaving the plants up after blooming could result in reseeding. Any diseased asters should be completely removed before winter, cleaning up all debris at the base of the plants.
Asters can provide green plants in the summer and beautiful blossoms in the autumn. They are definitely worthy of consideration for any Ozark garden landscape.
Questions or comments related to gardening? Contact Joleen at missourigardener@hotmail.com
This column is part 2 of 2.