Asters: Growing Tips for Autumn’s Favorite Perennial

asters

Asters bring intense shades of purple, blue, pink and fuchsia mounds of dense daisy-shaped flowers that act as a farewell celebration and rousing “Grand Finale” to fall gardens.

Asters are native perennials and were unruly over-grown plants when discovered by early settlers. Today’s hybrid Asters have come a long way and are now shorter, denser flowering, and one of the most important perennials in the garden not only for their jeweled, royal colors but also as the final feeding place of the pollinators stocking up on food for winter.

asters pink and rose

Some Aster Varieties You’ll Love:

‘Purple Dome’ Asters are favorites due to their 15×15-inch, tidy, compact size and the deepest of deep purple color. This hybrid must be propagated by division or cuttings to maintain their perfection for seed varieties are often tall and gawky.  With hybrid Asters like ‘Purple Dome’ (see photo at the beginning of the article) it’s important to not let them go to seed so they need to be deadheaded after the first killing frost. Asters are vigorous, so divide the hybrids at least every four years or they may revert back to their native roots. This isn’t easy to remember for spring division is best and by spring, gardeners have forgotten about Asters. Because they are slow to break dormancy, they are hard to locate because their early foliage resembles many other perennials. A stake placed in the Aster bush may help the gardener to remember

asters-purple-dome-reverted
Above, a reverted ‘Purple Dome’ aster that has reverted back to it’s native roots.

The tall, gangly aster bush behind ‘Purple Dome’ is a reverted seedling from the hybrid and not many gardeners would like this perennial in their gardens for the bush will flop, revealing mildewed dried looking stems with brown brittle leaves. Mildew can be an Aster problem if the perennial is kept too wet, too dry, or too crowded. Fortunately living in the arid climate of the west, hybrid Asters rarely suffer from mildew.

Other amazing Aster hybrids are the Asters X dumosus, ‘Woods’ series. These are even smaller (about 10 inches) than the ‘Purple Dome’ and are so close to the ground that nothing bothers them. ‘Woods’ are just the right size to place along front flowerbed edges,  in containers or rock gardens.

woods blue aster
“Woods” blue aster. Photo courtesy Walters Gardens

Picking a favorite Aster is not really appropriate but the Aster ‘Alert’ is mine. The hybrid ‘Alert’s 12-inch size is between ‘Purple Dome’ and the ‘Woods’ series, and Alert is an earlier bloomer. The brilliant fuchsia colors of ‘Alert’ are probably the main reason I love this perennial so much, for no matter where it is planted, it adds that touch of red that is so important in any garden.

asters alert variety
Aster ‘Alert’ variety

Asters are considered deer resistant for if their leaves get crushed they smell faintly of turpentine. They are also the flower for the month of November and the symbol of love. Asters? What’s not to Love!

Tips for Dividing Asters

Here, UNL Assistant Manager for Landscape Operations Jeff Culbertson shows how to divide fall blooming asters in the springtime.

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