How to Plant a Sunflower Bed: Spacing plus Staking
Learning how to plant a sunflower bed comes down to spacing by size. University of Minnesota Extension suggests sowing seeds one inch deep after all danger of frost, leaving about 6 inches between 2 to 5 foot types, at least 1 foot for taller types plus 2 feet for giants. Seeds germinate within 7 to 10 days.
The short answer
Sow sunflower seeds 1 inch deep after the last frost in full sun plus well drained soil. Space 2 to 5 foot types about 6 inches apart, taller types at least 1 foot plus giants 2 feet. Giants over eight feet sometimes need stakes. Sow the same variety every one to two weeks for season long bloom.
How much space do sunflowers need?
Spacing scales with height. University of Minnesota Extension gives these figures for direct seeded sunflowers planted one inch deep after frost.
| Type | Height | Spacing |
|---|---|---|
| Dwarf | 3 feet or less | Fits containers plus bed fronts |
| Short varieties | 2 to 5 feet | About 6 inches |
| Taller varieties | Over 5 feet | At least 1 foot |
| Branching | Large, many blooms | 18 to 24 inches |
| Giant | 8 feet or more | About 2 feet |
Source: University of Minnesota Extension.
Which sunflowers need staking?
University of Minnesota Extension notes semi dwarf cultivars of three to eight feet usually do not need staking, while giant cultivars of eight feet or more sometimes do because of plant, flower plus seed head size. NC State Extension suggests a sheltered spot for taller varieties to limit wind damage.
How does succession sowing extend bloom?
University of Minnesota Extension lists three ways to have sunflowers blooming all season. Plant several varieties with different days to maturity at once, sow the same variety at one to two week intervals, or sow varieties with varying maturity at three to four week intervals.
How to: step by step
- Wait until all danger of frost is past.
- Pick a full sun bed with well drained soil.
- Sow seeds 1 inch deep.
- Space by full height.
- Stake giant types as they gain height.
- Sow again every one to two weeks.
Troubleshooting
Stems flop: tall type in wind. NC State Extension suggests a sheltered spot plus stakes.
Young plants vanish: deer or other wildlife. University of Minnesota Extension notes deer can destroy young plants quickly.
Short bloom period: single sowing. Sow at one to two week intervals.
For related reading see planning an outdoor cannabis garden layout, what roles do bees play in outdoor cannabis plus plant cages for cannabis. Kind Seed Co also stocks cannabis seeds.
Sources
- Sunflowers, University of Minnesota Extension
- Sunflowers, UF/IFAS Gardening Solutions
- Helianthus annuus (sunflower), NC State Extension Gardener Plant Toolbox
FAQ
When should sunflowers be planted?
University of Minnesota Extension suggests direct seeding after all danger of frost has passed. NC State Extension notes sunflowers are not frost tolerant plus grow most vigorously between 70 plus 85 F. In Florida, UF/IFAS notes plants are seeded in late winter to early spring for warm season bloom.
How far apart should sunflowers be?
University of Minnesota Extension suggests about 6 inches between varieties 2 to 5 feet tall, at least 1 foot for taller sunflowers plus 2 feet for giants. Branching cultivars need 18 to 24 inches because they grow quite large. Wider spacing for giants also helps air circulation around the plants.
Do sunflowers need staking?
Only the tall ones. University of Minnesota Extension notes semi dwarf cultivars usually do not need staking, while giants over eight feet sometimes do. UF/IFAS notes taller varieties may need stakes, plus NC State Extension suggests a sheltered spot for them. Stakes support the stems of the tallest plants.
Can sunflowers grow in pots?
Dwarf types can. University of Minnesota Extension notes dwarf cultivars three feet tall or less work well in limited spaces or containers, naming 'Teddy Bear', 'Sunspot' plus 'Ms. Mars'. For indoor starts it suggests biodegradable pots, planted whole so seedling roots stay undisturbed, with any rim above soil removed.
What soil do sunflowers prefer?
University of Minnesota Extension notes sunflowers grow most vigorously in well drained soil with a pH from 6.0 to 6.8, plus they tolerate clay loam or silty clay loam. NC State Extension notes they tolerate poor plus dry soils once established. Both sources call for full sun in the bed.
