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Planting, Growing, and Caring for Asters
Planting
Asters prefer areas with cool, moist summers and cool nights in sites with full to partial sun. In warmer climates, asters do not like the hot midday sun. Soil should be moist but well-draining and loamy. Wet clay soil will lead to root rot, and dry sandy soil will lead to plant wilt. Mix 2 to 3 inches of compost into the soil before planting.
When to Plant Asters
- The best time to put young aster plants in the ground is in mid- to late spring after the danger of frost has passed. (See local frost dates.)
- Or, you can plant mature, potted asters when available at garden centers (typically in the late summer or early fall).
- Asters can be grown from seed, but germination can be uneven. If desired, plant seeds in the fall or start them indoors in the winter.
How to Plant Asters
- When planting young aster plants outside in the spring, space them 1 to 3 feet apart, depending on the type and how large they’re expected to get.
- Fully grown asters, such as those available in late summer or early fall, should be planted about 3 feet apart.
- If planting seeds, sow 1 inch deep in pots or flats and refrigerate them for 4 to 6 weeks to simulate winter dormancy. This cold period will kick-start germination.
- Water well, and spread mulch around the plants to keep the soil cool and prevent weeds.
Catherine Boeckmann
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I challenge this statement: "Asters prefer areas with cool, moist summers and cool nights in sites with full to partial sun." While the native asters in the yard did not do that well during drought conditions in the northeast, the ultra-hot weather this year, combined with higher rainfall produced tall plants with ample blossoms.
Hi JR,
While asters prefer cooler conditions that does not mean the plants can not survive and even thrive during stretches of hotter conditions, especially once they are established. The flowers do best when the temperatures are cooler in the late summer and fall. Since asters prefer moist soil, it is important that they receive enough water/precipitation to keep them growing during hot and/or dry stretches.
Hot weather can cause plants to be affected, which is why it is important in warmer climates to plant them in an area where they receive some shade during the midday sun. And once cooler temperatures return they tend to bounce back quite well.
I have a beautiful very large purple aster they I would like to split up and replant this fall is that a good idea.?
It’s best to divide flowering plants when they are not blooming. Because asters bloom so late into the year, it’s usually best to wait until early spring to divide and transplant them (chrysanthemums, too).
May I split up a very large aster plant in the fall
Can they take heavy humid hot days of our summers??
I had planted some Aster Flowers, this fall, so that I start getting flowering from the starting summer, few of them started drying up. So I bought a net from Olmsted's Nursery to avoid excess sunlight. Now they are doing well. Thank You!
I am planning to plant some Aster Flowers this fall, so that I start getting flowering from the starting summer. Thank You!
Growing asters
We just had a couple of unusually hot days for Ohio.My potted Aster just lost the majority of its blooms.They turned brown and shireveld up.Kinda was hoping to plant this one soon,but now unsure
