Sunflowers are cheery annual plants that can easily be grown in home gardens. With their bright floral displays and towering heights, these flowers make a stunning addition. By following some key sunflower plant care tips, you’ll be rewarded with vigorous sunflowers that last all season long.
Choosing the Right Sunflower Variety
When starting sunflowers, the first step is choosing an appropriate variety. Take into account the following factors:
- Mature Height: Sunflowers can range from dwarf types under 3 feet to giant varieties over 12 feet tall. Select based on your garden size and needs.
- Bloom Size: Flowers can be under 3 inches across to over 1 foot wide. Larger blooms make bold accent plants.
- Bloom Color: Choose from classic yellow and orange tones to unique bicolors and shades of red, burgundy, and pink.
- Duration: Blooming lasts from a few weeks to several months depending on variety.
- Purpose: Consider if you want flowers for cutting, bird and wildlife habitat, or seed harvesting.
- Climate Suitability: Check variety hardiness ratings and heat tolerance for your growing zone.
Sun-loving sunflowers require a site with full sun exposure. Select a spot that gets at least six to eight hours of direct sunlight daily. The soil should be fertile, well-drained, and weed-free. Give plants ample room to develop, allowing proper air flow. Shelter from strong winds also encourages success.
Selecting the Perfect Planting Location
- Choose an area receiving at least 6-8 hours of full sun daily.
- Test soil drainage and pH. Sunflowers prefer slightly acidic to neutral levels.
- Eliminate grass and weeds which will compete for water and nutrients.
- Allow proper spacing for air circulation and mature size.
- Site near walls, fences or trellises to protect from wind damage.
Sunflowers thrive among corn, beans, squash and many wildflowers. Native Americans interplanted them with these companions. Complementary flowers help repel pests, attract pollinators, and improve soil health.
Preparing the Soil
Preparation is key for healthy sunflowers. Remove any grass or debris from the intended planting area. Till the soil to a depth of 12 inches, working in ample organic compost. This improves drainage and provides nutrients.
- Clear area of all weeds, rocks and debris
- Loosen soil to a depth of 12-18 inches with a tiller
- Incorporate 2-4 inches of compost or rotted manure
- Test pH and amend soil as needed to pH 6.0-7.5
- Double dig beds to improve drainage in heavy soils
- Consider planting sunflowers with beneficial companion plants
Planting Sunflower Seeds
Direct sow seeds according to package directions. Follow these tips:
- Plant seeds at recommended depth, usually 1-2 inches
- Space seeds 6-12 inches apart depending on variety
- Water gently after planting to settle seeds
- Keep soil evenly moist during germination period
- Thin emerging seedlings to proper spacing
- Provide support for tall varieties as they grow
- Rotate plants occasionally for even sun exposure
- Monitor for pests and treat promptly
Proper care is vital throughout the growing season. Sunflowers are heavy drinkers, requiring about an inch of water per week. Mulch conserves moisture while suppressing weeds. Apply a balanced fertilizer at planting time. Too much nitrogen leads to excess foliage over flowers. Turn plants frequently so all sides get sunlight.
Caring for Sunflowers
Watering
- Require 1-2 inches of water weekly, more in extreme heat
- Water at base of plants to keep foliage dry
- Allow soil to partially dry between waterings
- Add mulch to retain moisture and reduce weeds
Sunlight
- Rotate plants every few days for even exposure
- Monitor for leaning stems and reposition
- Remove obstructing weeds and foliage
- Site in full sun location with reflection if possible
Fertilizing
- Incorporate compost or fertilizer at planting time
- Use balanced fertilizer to avoid excess nitrogen
- Follow package instructions carefully
- Fertilize again if growth seems deficient
Support
- Insert tall stakes 1-2 feet into ground
- Tie main stem loosely to stake as it grows
- Use mesh cages for extra support if needed
- Check ties regularly and adjust as needed
Pest/Disease Control
- Scout for signs of problems and treat early
- Remove diseased plants immediately
- Introduce beneficial insects
- Use neem oil or insecticidal soap sprays
- Improve air flow and avoid overwatering
Watch for pests like aphids and caterpillars. Control with natural methods like insecticidal soap. Scout for diseases and remove afflicted plants immediately. Most problems arise from overwatering or poor air circulation.
Troubleshooting Sunflower Plant Care
Poor Germination
- Ensure planting at correct depth
- Maintain even soil moisture
- Check seed viability and proper storage
Stunted Growth
- Test and amend soil as needed
- Provide sufficient water and nutrients
- Allow proper sunlight and spacing
Leaning Stems
- Stake plants properly to avoid wind damage
- Space plants far enough apart
- Ensure adequate moisture to stems
Pest Damage
- Identify pests and treat organically
- Remove badly damaged plants
- Clean up debris to eliminate hiding places
- Introduce beneficial insects
Diseases
- Improve air circulation
- Avoid excess moisture on leaves
- Remove and destroy affected plants
- Treat organically with neem oil or sulfur
No Blooms
- Minimize nitrogen fertilizer which promotes foliage over flowers
- Provide phosphorus fertilizer to stimulate blooming
- Check for proper sunlight and maturity
Harvesting Sunflowers
Follow these tips for collecting seeds from your sunflowers:
- Allow flower heads to fully mature and turn brown
- Cut stems leaving about 12 inches attached
- Hang upside down in a dry, well-ventilated area
- After 2-3 weeks, rub seeds off heads
- Separate seeds and debris
- Store seeds in airtight containers in a cool place
With some simple tips, you can enjoy nonstop sunflowers. Save seeds for replanting or make successive sowings for continuous blooms. Soon these iconic flowers will be lighting up your landscape.
Continuous Harvest
- Make successive plantings every 2-3 weeks for ongoing blooms
- Save seeds from favorite plants for future plantings
- Store seeds in cool, dark place in airtight containers
- Start seeds indoors 6-8 weeks before last frost for a head start
- Protect young shoots with cloches to extend the season
The Best Sunflower Varieties
| Variety | Height | Color | Blooms | Use |
|---|---|---|---|---|
| Moulin Rouge | 4-5 feet | Red/yellow | 4-6 inches | Cut flowers |
| Autumn Beauty | 6-7 feet | Mix of bronze, yellow | 4-6 inches | Cut flowers, pollinators |
| Strawberry Blonde | 5-6 feet | Pink/orange | 5-6 inches | Landscapes, pollinators |
| Velvet Queen | 5-6 feet | Dark red | 6-8 inches | Cut flowers |
| Skyscraper | 10-12 feet | Yellow | 4-6 inches | Landscapes, backgrounds |
| Sunspot | 2-3 feet | Yellow/Mahogany | 4-5 inches | Containers |
| Titan | 12-14 feet | Yellow | 8-12 inches | Largest blooms |
| Russian Mammoth | 10-12 feet | Yellow/gray striped | 12-14 inches | Giant seed producer |
| Black Oil | 5-6 feet | Yellow | 5-6 inches | Edible seeds, oil |
| Wild Sunflower | Variable | Yellow | 2-4 inches | Naturalized meadows, wildlife |
With thousands of sunflower varieties to choose from, there are endless options to suit your taste and garden goals. Give some of these top performers a try for showstopping flowers.
Growing Sunflowers in Containers
Sunflowers can be successfully grown in containers with proper care. Follow these tips:
- Select a dwarf or patio variety under 3 feet tall
- Choose a container at least 12 inches wide and deep
- Use a quality potting mix and provide drainage holes
- Site the container in full sun
- Stake taller plants for support against wind
- Water when soil surface is dry to the touch
- Feed with a balanced liquid fertilizer
- Move container grown plants indoors if temperature drops below 50°F
Even if space is limited, anyone can enjoy growing mini sunflowers on a balcony or patio for cheery pops of color through the seasons.
Sunflower Care Calendar
Follow this monthly calendar for the best sunflower care:
March-April
- Conduct a soil test
- Add compost and fertilizer as needed
- Sow seeds indoors for transplanting
May
- Sow seeds directly in ground after danger of frost
- Plant seedlings outdoors after hardening off
- Water and protect seedlings from birds and rodents
June-July
- Water 1-2″ per week unless rains suffice
- Weed and mulch around plants
- Stake and tie tall plants as needed
- Watch for insect pests and treat organically if found
August-September
- Monitor soil moisture as sunflowers mature
- Harvest sunflower heads when backs are yellow/brown
- Cut flowers as desired for arrangements
October
- Pull up spent sunflower plants after heavy frost
- Prepare soil for next season by tilling in organic matter
- Save seeds for future planting
Frequently Asked Questions
How much sun do sunflowers need?
Sunflowers require a minimum of 6-8 hours of full, direct sunlight per day. Choosing a planting site that receives sun from morning to evening is best.
When should you plant sunflower seeds outdoors?
Direct sow sunflower seeds in the garden after the last spring frost date when soil temperatures reach at least 55°F. This is usually early to mid May in most regions.
How much space do sunflowers need?
Spacing depends on the variety, but most sunflowers need at least 6-12 inches between plants. Giant types over 5 feet tall can be spaced 1-2 feet apart.
Can you grow sunflowers in containers?
Yes, dwarf and patio type sunflowers varieties under 3 feet tall can be successfully grown in containers as small as 10-12 inches wide and deep. Ensure adequate water, fertilizer, and sunlight.
How can you keep birds from eating sunflower seeds and seedlings?
Deter birds by placing scare-eye balloons, aluminum foil pans that reflect light, or owl decoys around the planting site. Also cover tender shoots with row covers.
What causes the petals of my sunflower blooms to drop off prematurely?
This can be caused by too much nitrogen fertilizer, drought stress, high winds, or aging blooms. Test soil, check moisture levels, stake plants, and remove spent flowers to encourage new growth.
Additional Tips and Tricks
- Start a sunflower house or fort for kids by planting seeds in a square shape and tying interior stems together once they grow.
- Brew a tea from sunflower leaves and petals – simply steep in hot water for a few minutes to release their mild flavor.
- Create a natural sunflower dye from petals boiled in water to produce a golden yellow hue perfect for Easter eggs.
- Stuff large sunflower seed heads with suet, chopped nuts, dried fruits or peanut butter for an easy DIY bird feeder.
- Dry and display spent sunflower blooms by hanging them upside down in a cool, dark place for weeks until crispy.
