How to Plant and Grow China Aster

China aster (Callistephus chinensis), an easy-to-grow annual known for its showy blossoms, is a favorite cut flower that blooms in late spring or early summer through fall. This cool-weather plant comes in an array of colors and heights.

The white, pink, red, blue, violet, purple, or yellow flowers typically open to 3 to 5 inches in diameter, depending on the variety. The most common form is a single row of colorful petals around a yellow central disk; however, there are semidouble types with several rows of outer petals around a yellow disk, double blooms with no yellow center visible, and shaggy pompoms popular in bouquets. The oval medium-sized green leaves have slightly serrated edges.

Where to Plant China Aster

Plant china aster in garden beds, cutting gardens, or containers. It grows best in moist, loamy, well-draining soil but tolerates other soil conditions. Situate the plants in full sun to partial shade.

How and When to Plant China Aster

China aster is easy to start from seed. When starting indoors, sow seeds six to eight weeks before the last spring frost date. If sowing directly in a garden bed, sow seeds after the last spring frost date with successive plantings at two-week intervals. Cover the seeds with 1/8 inch of soil and keep the soil moist. With a soil temperature of 65-70°F, the seeds should germinate in 10-15 days. The plants appreciate good air circulation, so thin the seedlings to 6-12 inches apart. Tall varieties may require staking or other support.

China Aster Care Tips

Light

China asters grow in full sun or partial shade. When grown in hot climates, they benefit from some midday shade.

Soil and Water

You'll get an upright plant with vibrant colors when China aster is planted in rich, consistently moist, well-draining soil with a pH of 5.5–7.5. Water the plants twice a week—more often in dry climates.

Temperature and Humidity

A cool-season grower, China aster will not be happy in warm Southern climates during the summer. If it gets too hot, the plant will likely stop blooming, but it comes back in fall with another cool-season show.

Fertilizer

During the growing season, fertilize China aster with a balanced 10-10-10 water-soluble fertilizer every two weeks, following the instructions on the product packaging.

Pruning

To create a bushier plant and additional blooms, cut it back to half its height in midsummer.

Potting and Repotting

China aster is a shallow-rooted plant that grows well in containers as long as the soil never dries out. Choose a container an inch wider than the mature plant, making sure it has drainage holes. Fill it with commercial potting soil and add the plant. Spread a layer of mulch on the soil to retain moisture, and water the plant at its base once a week.

Pests and Problems

China aster is susceptible to a few pests, including aphids and spider mites. Potential diseases include aster yellows, aster wilt, and stem rot. The best solution is to dig up and remove any diseased plants. You may also need to move plants to different locations each year to prevent transmission of diseases.

Use these garden pest control methods to protect your China asters.

How to Propagate China Aster

China asters are annuals that are best propagated by seed. After the blooms are spent, the seed capsules ripen. Cut them and separate the seed from the chaff, or hang them to dry above a tarp that catches the falling seeds. Plant them 1/8 inch deep in seed-starting mix in a seed flat in early spring and keep them in bright light until they germinate, or sow the seed outdoors when the soil warms.

New Innovations

Work is ongoing to develop even more eye-catching varieties on sturdier stems to take advantage of these long-lasting flowers in bouquets. There are also varieties being grown with the home gardener in mind. Because of this, many different heights are available.

Types of China Aster

'Matsumoto' China Aster

Callistephus chinensis 'Matsumoto' is a tough, wilt-resistant aster. This series has semidouble flowers in just about every color and reaches 24 to 30 inches tall. Great for cutting.

'Milady' Series China Aster

Callistephus chinensis 'Milady' series is a fully double series with chrysanthemum-like blooms in a wide variety of colors. This series also has good wilt resistance.

'Starlight' Mix China Aster

Callistephus chinensis 'Starlight' mix has threadlike petals in a variety of jewel tones. These blooms look like fireworks. Dwarf plants are great for containers or the front of the border.

Plant China Companion Plants

Coralbells

Exciting new selections with incredible foliage patterns have put coralbells on the map. Previously enjoyed mainly for their spires of dainty reddish flowers, coralbells are now grown as much for the unusual mottling and veining of different-color leaves. The low clumps of long-stemmed evergreen or semi-evergreen lobed foliage make coralbells fine groundcover plants. They enjoy humus-rich, moisture-retaining soil. Beware of heaving in areas with very cold winters.

Marguerite Daisy

For a spectacular show during cool weather, plant marguerite daisy. Often confused with shasta daisy, marguerite is more mounded and shrubby. Different types also come in pink with a bloom resembling purple coneflower. Marguerite daisy's hallmark is that it loves cool weather—and blooms best in most areas in spring and fall, though it will continue to bloom through the summer in mild-summer areas. Even when it's not in bloom, the dark green, finely cut foliage looks good against just about any light-color flower.

Fountaingrass

Like many grasses, fountaingrass is spectacular when backlit by the rising or setting sun. Named for its exceptionally graceful spray of foliage, fountaingrass also sends out beautiful, fuzzy flower plumes in late summer. The white, pink, or red plumes (depending on variety) continue into fall and bring a loose, informal look to plantings. This plant self-seeds freely, sometimes to the point of becoming invasive.