Fall asters bring Texas to Texans

You may be out hiking in the Hill Country and come across a lovely little aster-like plant blooming its heart out in the fall. You may wonder why it’s not grown in Texas landscapes.

Well, funny you would ask, because plant searchers had those very same thoughts generations ago. They brought this lovely little native Texas wildflower back to their gardens and found it to be quite dependable.

However, the story just about ended there. For decades this was only a passalong plant, handed from one gardener to another. That works fine if you know someone who has one, and if you know the plant in the first place. But unless you see this plant in flower, you’re never going to remember it. With its tiny stature and small green leaves, it disappears into its surroundings. But when it pops into bloom in the fall, wow! That’s when it puts on its big show to behold.

Here are the details you’ll want to remember.

Critical facts…
Common names: Fall aster, aromatic aster.

Scientific name: Symphyotrichum oblongifolium.

Native range: New York west to Montana, then straight south to New Mexico and east to North Carolina. The only states left out of that big block of the U.S. according to the USDA are Louisiana, Florida, Georgia, and South Carolina.

In Texas, you’ll find them in the Cross Timbers, Edwards Plateau, and scattered prairie sites of the Texas Hill Country. As a high schooler I saw this plant in those areas as I worked alongside my dad as he conducted his research on plants toxic to livestock for Texas A&M. He tried to schedule his work trips to coincide with my time off from school so I could go with him.

U.S.D.A. Plant Hardiness Zones: 4-7

Exposure: Full sun but will tolerate light shade.

Mature size: 1-3 ft. tall and wide. It will grow taller in partial shade – all the more reason to grow it in full sun. Shear it back by 25 to 30 percent in late May or early June to keep the plants compact. That will produce the best overall floral show.

Flowers: “Daisy-like,” Sept.-Nov., lavender/purple with yellow centers.

Pest problems: There are no major insect or disease issues with fall asters in the landscape.

Bed preparation: Although they’re native to a variety of soils, fall asters in the landscape will do best if they’re planted in highly organic garden loam that can be kept moist all through the growing season.

Fertility needs: Feed lightly with a high nitrogen lawn-type fertilizer to keep your plants growing actively. Over-feeding, however, will lead to spindly growth. Feedings should be timed for early spring as growth begins and immediately after the late-spring shearing. Do not fertilize from mid-summer on as your plants will be setting flower buds at that time.

Management after the growing season: Prune the current season’s stems back near the soil line at the end of the growing season. You should be able to see the next season’s shoots starting to develop. Leave short stubs of the old stems in place to protect them much as you do with chrysanthemums. Dig and divide your plantings every 3-4 years to keep your plants vigorous.

Propagation: Can be started from softwood cuttings taken in late spring or by divisions taken from the bases of the plants in fall or early spring. The plants do produce seed, and they could be used for propagation, but the other methods will be easier.