Mammoth
Sunflower · Confection / Edible Seed
Heirloom
Helianthus annuus
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Asteraceae (Sunflower family) · Genus: Helianthus
Characteristics
Color
Multi-Color
Growth Habit
Single-Stem
Intended Use
OrnamentalSeed Harvest
Size
Giant
Texture
Meaty / Dense
About the Plant
Life Cycle
Annual
❄
Hardiness
Warm-Season/Tender
☀
Exposure
Full Sun
💧
Moisture
Drought-Tolerant / Low Water
🌍
Origin
Russia
🌱
Germination
7–10 days
at 50 °F
⏳
Days to Maturity
80–120 days
Plant Height
9–12 ft
Mature Spread
3–3 1/3 ft
Fruit Size
10–12 in
How to Plant
🏠
Start Indoors
2-4 Weeks Before Last Frost
Transplant
0-2 Weeks After Last Frost
🌸
Direct Sow (Spring)
0-2 Weeks After Last Frost
Planting Depth
1/2–1 in
Seed Spacing
6 in
Row Spacing
30–36 in
Thin To
24–36 in
🌡
Optimal Soil Temp
70–85 °F
🌡
Soil Temp
50 °F
🌡
Air Temp
25 °F
When to Plant in Your Area
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