Aster season: Starry, starry days

'Pink Mist'/Proven Winners

Call it the result of a wildly successful marketing campaign or call it habit, most gardeners automatically reach for chrysanthemums when they crave a late-season blast of color.

Well and good – there’s a lot to like about the popular mum, a plant that comes to us from the gardens of imperial China and Japan. But let’s not overlook the all-American aster, a native plant that grows wild in fields and meadows from Maine to Florida and west to the Great Plains. The refined hybrids developed from this widespread wildflower deserve a leading role in any autumn planting scheme.

“Aster” is Latin for “star,” and the name is self-explanatory when you see the flower’s fine petals radiating from its bright yellow eye. These plants are stars in another sense since they cover themselves with more blossoms than the average person has patience to count.

The real value of asters may be the range of cool blues, acid pinks and vibrant purples that they add to the fall palette – colors not easily found in other late bloomers. Also worth mentioning is that asters are true perennials, unlike many mums bred for looks, not hardiness.

Potted mums tend to have a rather stiff appearance, looking like symmetrical little muffins all abloom. Asters are more relaxed in their habit of growth and are easier to work into a mixed border. With nearly 500 species contributing to the gene pool, asters range from dwarf plants ideal for the rock garden to oversized giants like the 7-foot- tall wood aster.

In Britain, where asters are much in favor, they are often known as Michaelmas daisies. Michaelmas is the feast of St. Michael the Archangel, celebrated on Sept. 29 when asters are at their peak. It’s a holiday of the harvest, marked in the British Isles with feasts of roast goose, autumn vegetables and freshly pressed cider. (Sounds good to me.)

In the US, the aster season generally runs from mid-September through October, but may continue into November if the weather stays mild.  Asters are easy to grow, most requiring nothing more than full sun and well-drained soil.

Blue and white wood asters (Aster divaricatus and Aster cordifolius) take a fair amount of shade and are suitable for woodland margins. New York and New England asters (Aster novi-belgii and Aster novae angliae) can thrive in marshy locations subject to periodic flooding, and other species, including the Pinelands showy aster (Aster spectabilis,) tolerate drought and do fine in sandy soils.

Asters can be planted in spring or fall, but buying now allows you to see plants in bloom. As a rule of thumb, space them 18 to 24 inches apart, depending on height. Situate them behind earlier blooming summer perennials since they are unremarkable through much of the growing season.

Asters need at most a light dose of fertilizer in the spring; a rich diet can push foliage at the expense of flower formation. They seldom are bothered by insect pests, although powdery mildew may appear in wet weather or among crowded plants. Bunnies are one of the chief nuisances when asters first emerge – fences or repellants may be needed until plants are large enough to tolerate nibbling.

While taller varieties may require staking, most asters can be kept compact with a few rounds of pruning or pinching. Shorten new shoots by half from late spring to mid-July, stopping then to allow flower buds to form. No special winter protection or care is required.

As native plants that evolved with wildlife, asters offer nectar, seeds and shelter to desirable wild critters. Plant asters and they will come – bees and butterflies to the blossoms, goldfinches and other birds to the dried seed heads and the ladybugs to spent foliage where they find cozy winter quarters. Wildlife-friendly asters have it all over mums, which often are sterile as a result of sophisticated breeding for color and form.

Beef up your garden’s fall attractions and you won’t think the season ends on Labor Day. There’s a lot to enjoy at home once you wash the beach sand off your feet – asters being one good reason to look forward to autumn in the garden.

Mail order sources:

Bluestone Perennials, 7211 Middle Ridge Road, Madison, OH 44057. Call 800-852-5243 or see bluestoneperennials.com.

High Country Gardens, Box 22398, Sante Fe, NM 87502. Call 800-925-9387 or visit highcountrygardens.com.

Proven Winners, provenwinners.com. Check this website to find a local retailer or to buy mail order plants.