Climate Preferences: Asters love regions areas that are neither very dry nor very wet, with cool summer nights.
Sun Exposure: Partial shade to full sun.
Landscaping Tips: Since many varieties of aster bloom in the fall, consider planting asters in areas that lack color after the summer. Taller varieties of aster look great in for back of a sunny bed. These varieties may require staking, so take the use of stakes into consideration when planning.
Planting: Plant potted asters 1-3 feet apart, depending on the expected size of the Aster variety. Mix in a small amount of organic fertilizer at planting, and water in well.
Water regularly if your plants receive less than one inch of rain per week, but do not overwater.
Water the bases of the plants, and soak the ground well. Continued light watering, or watering of the leaves and flowers, may cause problems such as stem rot for these thin-stalked plants.
Water in the morning or evening, not in the heat of the day.
Compost and mulch: add a thin layer of compost, plus a two-inch layer of mulch, over the soil every spring.
Taller varieties may need to be staked. Shorter varieties may require cutting back in early summer to encourage growth.
Asters grow and multiply quickly, so plan to divide them once every two to three years.
May is the best month for moving and dividing asters, since new shoots emerge around that time.