Gro 'n Sell
Aster (Callistephus)
Like round puffy flowers with lots of petals? You're in luck.
China asters, or Callistephus are best transplanted after the soil has warmed in the spring. They establish under the long days of summer and then initiate bud as the days shorten. You can manipulate flower size and stem length by pinching or not pinching; disbudding or not. They respond well to human intervention!
**We do not guarantee any specific shades will appear in Mix products, as the Mix is created by the seed breeder. It is possible that Mix will be all one color, or significantly different from pictured colors. If you need specific shades, please order straight colors as opposed to Mix trays.**
Grown in a 216 tray, billed as a 210.
Order 6 or more weeks before desired ship date.
About Tray Sizes
210 and 125 cell trays are full-sized trays, and three of these will fit in a shipping box.
50 cell trays are half-sized trays (unless otherwise noted) and two of these are the equivelent of one full sized tray. Six of these will fit in a shipping box.
18 and 32 cell trays are full sized trays specifically for our vernalized perennials. These have their own set of shipping rules (find details HERE) and cannot be combined with items grown in 210, 125, or 50 cell trays.
Growing Guide
Click here to access all of our comprehensive growing guides.
| Common Name | Aster |
| Genus | Callistephus |
| Species | chinensis |
| Family | Asteraceae |
| Life Cycle | annual |
| Format | Plugs |
| Plug Care | Harden off plugs before transplant. Asters are sensitive to day length and stress conditions. In order to maximize stem length, do not delay transplanting. |
| Netting / Staking | Hortonova netting is recommended. |
| Temperature Range | Best transplanted after soil has warmed in the spring and stays over 55F at night. |
| Spacing | 6" |
| Soil Preference | Select a cut flower bed rich in organic matter where asters have not been grown the previous year. To prevent problems with fusarium grow in the same field every other year. Good drainage is required. |
| Day Length | Asters flower under shortening days of late summer. If you have strong streetlights or other outdoor lights that cast into your Aster patch, consider blocking this light at night. |
| Pinching | For cut flowers, no pinch will result in very tall stems. If you desire branching, pinch deeply once, 14-18 days after transplant, leaving 3-5 internodes. |
| When to Plant | Spring, after danger of frost has passed. |
| Harvesting | For local markets, cut when flowers show full color but before pollen ripens. In general one can expect 5-7 flowers per stem. |
| Post Harvest Care | Strip off the bottom leaves and place stems in tepid water in a cool area for rehydration. Hold at 35-40°F. |
| Diseases / Insects | They are somewhat prone to many disease and pest issues, which limits their cultivation. Powdery mildew; rust; fusarium; whiteflies; thrips; spider mites. |
| Bailey's Notes | Callistephus establish under the long days of summer and then initiate bud as the days shorten. You can manipulate flower size and stem length by pinching or not pinching, or disbudding or not. They respond well to human intervention! |
| Resources | Sakata Aster Production Tutorial |