While summer flowers draw back, well-maintained asters will keep your ornamental garden vibrant and attract pollinators throughout the fall. They like full sun, loamy soil and lots of space to spread. Certain varieties do well in partial shade. Water infrequently but thoroughly, and consider mulching to assist with moisture and weed management. Taller varieties may need a cage or stake for support.

These flowers are pest-resistant, with the one major threat being lace bugs, which cause yellow foliage and leaf drooping. Use insecticidal soap to manage outbreaks. Good spacing and avoiding overhead watering will reduce the chances of diseases like powdery mildew or rust.

Asters are one of the tougher flowers to start from seed, which is why most gardeners propagate from existing plants. Nevertheless, you can try seeding if plants or seedlings aren’t available. Fill seed trays with a seed-starting mix 6-8 weeks before the final spring frost. Scatter the seeds and lightly cover them with soil. Keep the soil moist and at temperatures of 65-75 degrees. After germination, provide seedlings with lots of indirect sunlight or grow lighting. When the seedlings have multiple sets of true leaves, thin or transplant them to 6-8 inches apart.

You can plant asters anytime after the final spring frost, including the summer or early fall. Spacing should be 1-4 feet, depending on the variety. Avoid soil that is clay-based or sandy, as they’ll end up too wet or dry. Roughly every three years, divide and replant the root clumps, as the plant center tends to get woody over time. Note aster plants grown from seed can take up to four years to fully mature.

To plant aster in pots, you’ll need well-draining containers made of a sturdy material (ceramic, terra cotta, etc.). Use an all-purpose potting mix that stays loose. Container asters will need more water — sometimes daily in the hottest periods.

Regular feeding during the spring and early summer will prepare your asters for a colorful fall. Add a balanced, flower-specific fertilizer twice a month, or use organic matter like compost and manure. Stop fertilizing once the blooms start to open (usually early August), as continuing to feed past this time shortens the blooming period. Soil testing will tell you whether you need to adjust the frequency or provide specific nutrients.

In all but the coldest regions, aster can be overwintered in the ground. After the flowers stop blooming, provide the plants of 1-2 inches. Once the first fall frost happens, add a few inches of organic mulch for root insulation. You can cut back the foliage to conserve resources or leave it standing for wildlife to nibble.

Minimal pruning is necessary for the most bountiful aster plants. Remove dead or damaged stems as needed, and pinch off fading flowers so the plant can focus on new buds.

Cutting off flower stems for arrangements will also spur growth. Do so using sterile shears just before the flowers reach full bloom and immediately place them in water. To harvest seeds, let the seed heads dry, then gently pluck the heads off and place them in a paper bag.