Flower / Warm season
Mammoth Sunflower
Back-of-bed height, pollinator forage, and bird seed.
Large edible seed heads after flowering.
Seed spacing and maturity
- Days to maturity
- 90
- Germination temperature
- 65-85F
- Seed depth
- 1 inches
- Spacing
- 18 inches
- Row spacing
- 30 inches
- Start method
- Direct sow
Frost-date timing
- Direct sow
- 7 days after last frost
- Succession interval
- repeat every 21 days
Action plan
- Can I plant this now?
- Use your local last-frost, first-frost, and soil-temperature checks before treating this crop as plantable today.
- Start indoors or direct sow?
- Direct sow into the final bed when the soil temperature, seed depth, and moisture are ready.
- How much space?
- 18 inches in-row spacing, 30 inches between rows, and 1 inch seed depth.
- Best companions?
- Use this as part of a diverse flowering or herb planting, and treat companion claims as site-specific rather than guaranteed pest control.
- Common failure modes?
- Tall plants need space; do not shade shorter vegetables. Deep water while establishing; drought tolerant later. Average to fertile soil; stake in windy sites.
Growing profile
- Sun
- Full sun
- Water
- Deep water while establishing; drought tolerant later.
- Soil
- Average to fertile soil; stake in windy sites.
- Watch
- Tall plants need space; do not shade shorter vegetables.
- pollinators
- birds
- kids
- tall
Browse context
- Flower Catalog Category collection
- Aster Family Rotation and family context
- Warm Season Seeds Season collection
- Direct Sow Seeds Start-method collection
- Beginner-Friendly Seeds Practical trait collection
- High Pollinator Value Seeds Practical trait collection
- Succession Sowing Seeds Practical trait collection
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Source: Seed Savers seed saving guide