Asters
Seed # 137
Basic Information
- Seed Number
- 137
- Seed Name
- Asters
- Variety
- Purple
- Category
- Flower
- Plant Family
- Asteraceae
- Plant Type
- China aster (Callistephus chinensis)
- Planting Method
- Direct Sow or Transplant
- Seed Status
- In Seed Bank
- Created
- 2026-08-14 00:50:34
- Updated
- 2026-08-19 15:35:29
Planting Information
- Start Planting Date
- Mar 10
- Last Recommended Planting Date
- Jun 15
- Plantable Months
- March, April, May, June
- Indoor Start
- Mar 10 – Mar 24
- Direct Sow
- May 6 – Jun 15
- Transplant
- May 6 – May 31
- Indoor Start Weeks Before Frost
- 8 weeks
- Transplant Weeks After Frost
- 0 weeks
- Germination Days
- 10–14 days
- Harvest/Maturity
- Not recorded
- Succession Planting
- 14 days
Growing Conditions
- Ideal Soil Temperature
- 70-72°F
- Planting Depth
- 1/8 in
- Plant Spacing
- 6-12 in
- Row Spacing
- 12-18 in
- Thin-To Spacing
- 6-12 in
- Sun Requirements
- Full sun
- Water Needs
- Keep evenly moist but well drained; avoid prolonged leaf wetness
- Soil Preference
- Fertile, well-drained soil; approximately pH 5.5-7.5
- Minimum Container Size
- 2-3 gal
- Plant Height
- Not recorded
- Perennial/Biennial Status
- Annual
- Container Friendly
- Yes
- Trellis/Support Needed
- No
- Frost Tolerant
- No
- Heat Tolerant
- No
- Drought Tolerant
- No
- Pollinator Friendly
- Yes
- Medicinal
- No
Garden Uses
Container Cut Flower Pollinator Seed SavingCompanion Planting
| Plant | Relationship | Notes |
|---|---|---|
| Calendula | Good Companion | Not recorded |
| Calendula | Good Companion | Not recorded |
| Echinacea | Good Companion | Not recorded |
| Echinacea | Good Companion | Not recorded |
| Echinacea | Good Companion | Not recorded |
| Echinacea | Good Companion | Not recorded |
| Echinacea | Good Companion | Not recorded |
| Marigold | Good Companion | Not recorded |
| Marigold | Good Companion | Not recorded |
| Marigold | Good Companion | Not recorded |
| Marigold | Good Companion | Not recorded |
| Yarrow | Good Companion | Not recorded |
| Yarrow | Good Companion | Not recorded |
| Zinnia | Good Companion | Not recorded |
| Zinnia | Good Companion | Not recorded |
| Zinnia | Good Companion | Not recorded |
| Zinnia | Good Companion | Not recorded |
| Zinnia | Good Companion | Not recorded |
| Zinnia | Good Companion | Not recorded |
| Zinnia | Good Companion | Not recorded |
Storage
- Seed Source/Brand
- MSU Extension; Detroit frost dates; Almanac Detroit
- Packet Year
- Not recorded
- Quantity Notes
- Not recorded
- Purchase Date
- Not recorded
- Expiration Year
- Not recorded
- Storage Box
- Not recorded
- Container
- Not recorded
- Envelope
- Not recorded
- Row
- Not recorded
- Slot
- Not recorded
- Storage Notes
- Not recorded
Notes
Original Planting Method: Start indoors or direct sow
Outdoor / Direct Sow / Transplant Window: May 1 – Jun 20
Days to Harvest / Bloom: 90–120 days to bloom
Medicinal / Herbal Use: Mostly ornamental
Succession / Reusable Notes: Start indoors for earlier blooms.
Zone 6B Notes: Good late-season pollinator flower.
Companion Plants: Calendula, zinnias, marigolds, yarrow, echinacea, herbs, pollinator beds
Avoid Planting Near / Watch Outs: Crowding/wet foliage
Sources: MSU Extension: https://www.canr.msu.edu/resources/garden_planning_calendar | Detroit frost dates: https://www.ufseeds.com/vegetable-planting-calendar-detroit-michigan.html | Almanac Detroit: https://www.almanac.com/gardening/planting-calendar/MI/Detroit
[[RESEARCH ENRICHMENT START]]
Zone 6B: Grow as a cool-season annual. Start indoors 6-8 weeks before May 5 or direct sow after frost.
Germination: Sow approximately 1/8 inch deep at 70-72°F. Germination generally occurs in 10-14 days.
Harvest: For cut flowers, harvest when the outside ray florets begin opening and place stems immediately in water.
Seed Saving: Allow flower heads to dry fully. China asters can cross with nearby cultivars.
Special Care: The packet name 'Purple' does not identify a specific cultivar. The record uses species-level China aster information and leaves cultivar-specific height and maturity null.
Research Source: Johnny's Selected Seeds — https://www.johnnyseeds.com/growers-library/flowers/aster/china-aster-key-growing-information.html — Callistephus chinensis germination, spacing, soil, annual lifecycle and harvest stage
Research Source: NC State Extension Plant Toolbox — https://plants.ces.ncsu.edu/plants/callistephus-chinensis/ — China aster species identification, purple flower colors, pollinator value and variable cultivar size
[[RESEARCH ENRICHMENT END]]