Grow China aster as a one-season cut flower in full sun, in soil that stays moist but drains. China aster is also called annual aster. It is not a hardy perennial aster.
Give it full sun and soil that stays moist but drains
| Factor | Recommended | Avoid |
|---|---|---|
| Light | Full sun | Do not plant it in deep shade |
| Water | Keep the soil evenly moist | Do not let the bed dry out |
| Soil | Rich soil that drains | Do not plant into last year's aster bed |
| Air | Space the plants so air can move | Do not crowd the stems |
China aster is a one-season annual. Give it full sun and rich soil that stays moist but drains. A dry bed slows the bloom. Wilt and stem rot show up when you plant into the same ground year after year, so move the planting each spring and pull any plant that collapses overnight. [1] A pot works if the mix stays moist and the pot drains. [2] China Aster is Callistephus chinensis, a 1 to 3 foot mound with daisy-to-double heads in pink, white, blue, purple, red, or yellow.
Does China aster need full sun?
Yes. Full sun is the usual site. Light afternoon shade is fine in a hot summer, but deep shade gives weak stems and few flowers.
How often should I water China aster?
Keep the soil evenly moist. Water at the base when the surface starts to dry. Do not let the bed go bone dry, and do not leave the roots in standing water.
Set plants out after frost, 6 to 12 inches apart
Wait until frost has passed, then set starters or seedlings into the bed. Space them 6 to 12 inches apart so air can move. Tall stems may need a stake or a simple support net as they lengthen. [3]
- Wait until frost has passed and the soil has warmed.
- Set each plant at the same depth it grew in the pot, 6 to 12 inches from its neighbor.
- Water in once, then keep the soil evenly moist.
- Stake or net tall stems before they flop.
When do I set China aster in the garden?
Set plants out after the last frost, when the soil has warmed. Space them 6 to 12 inches apart.
Sow seed a little below the surface, 6 to 8 weeks before frost
Start seed indoors 6 to 8 weeks before the last frost, or sow in the garden after frost when the soil is about 65 to 70 F. Cover the seed with about 1/8 inch of mix. Keep that mix moist and around 70 to 72 F until seedlings show, usually in 10 to 14 days. Transplanting from a tray gives stronger stems than a late direct sowing. [4]
- Sow 6 to 8 weeks before the last frost, 1/8 inch deep, in a moist seed mix.
- Keep the mix around 70 to 72 F until seedlings show, usually in 10 to 14 days.
- Grow the seedlings in bright light. Do not let the cells dry out.
- Harden them off, then set them out after frost, or sow in place once the soil is about 65 to 70 F.
Can I grow China aster from seed?
Yes. Cover the seed with about 1/8 inch of mix. Start indoors 6 to 8 weeks before frost, or sow outdoors after frost when the soil is about 65 to 70 F.
Not a perennial aster
China aster is Callistephus, a one-season plant you sow each spring. A New England aster or New York aster is a hardy perennial with different care — see How to Grow Asters. A garden mum is Chrysanthemum — see How to Grow Chrysanthemums. Confirm the Latin on the tag before you count on it coming back next year.
Is China aster a perennial?
No. China aster is a one-season annual. Perennial asters such as New England aster come back for years and need different care.
Cut stems when the outer petals start to open
For a vase, cut the stem when the outer petals have started to open and the center is still tight. Put the stems in water right away. Expect about 7 to 10 days in a vase. If you leave the plant in the bed, pick faded heads so later buds can open.
- Cut when the outer petals have started to open.
- Strip the lower leaves and put the stem in water right away.
- Expect about 7 to 10 days in a vase.
When do I cut China aster for a vase?
Cut when the outer petals have started to open. Put the stems in water right away. Expect about 7 to 10 days in a vase.
If a plant wilts overnight, pull it, and sow next year's China aster in a new bed.
FAQ
Do you list pompon or peony China asters?
Those names describe flower form on the same annual, Callistephus chinensis. This catalog holds one China aster card. Give every packet the same sun and moist soil that drains.
Can I grow China aster in a pot?
Yes, if the pot drains and the mix stays moist. Compact plants fit a patio pot. Tall cut-flower stems still want sun and a stake.
Do I need to pinch China aster?
You do not have to pinch it. The plant branches on its own. If you want more side stems, pinch the tip once in early summer, knowing bloom may start a little later.
Is China aster toxic to cats and dogs?
It is listed as non-toxic to dogs, cats, and horses. Keep pets from chewing a lot of any garden plant. If a pet eats a large amount and looks unwell, call a veterinarian.
Will China aster come back next year?
No. Frost kills the plant. Sow again in spring, and use a new bed if wilt hit this year's planting.
Can I take cuttings?
The usual start is seed. Stem cuttings and division are not the method for this annual.
What about Matsumoto or Milady?
Those are extra shop series this catalog does not list as separate cards. Read the packet for height, then grow the plant in the same sun and moist, draining soil.
Can I grow it in a sunny window?
A bright window can hold a compact plant for a short season. Most gardeners grow China aster outdoors after frost, where the stems get enough sun and air.
Recommended plants
References
- [1] NC State Extension Gardener -
https://plants.ces.ncsu.edu/plants/callistephus-chinensis/ - [2] Gardening Know How -
https://www.gardeningknowhow.com/ornamental/flowers/china-aster/china-aster-cultivation.htm - [3] Harvest to Table -
https://harvesttotable.com/how-to-grow-china-aster-callistephus/ - [4] Johnny's Selected Seeds -
https://www.johnnyseeds.com/growers-library/flowers/aster/china-aster-key-growing-information.html
More first-season notes by plant are gathered in How to Grow Guides.
Updated: Reviewed by Bosquelle Editors