With their cheery faces and towering height, sunflowers are a beloved warm-season annual. The black oilseed type offers the bonus of highly nutritious seeds that both humans and birds relish. Black oilseeds are a cinch to plant directly in the garden from seed. Follow this guide for tips on when to sow, ideal planting conditions, proper planting techniques, and aftercare to get your patch of scrumptious sunflowers off to a vigorous start.
Choosing the Best Time to Plant Black Oil Sunflower Seeds
Sunflowers thrive when daytime temperatures are consistently warm, around 70°F/21°C or above. This allows the seeds to germinate readily and the seedlings to establish with robust growth. Here are planting guidelines based on region:
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Northern zones – Sow seeds directly in the garden 2-3 weeks after your last expected spring frost date once the soil has warmed,
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Southern zones – Start seeds in late winter/early spring 2-3 weeks before your average last frost date. Transplant seedlings to the garden after hardening off once danger of frost has passed.
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Extreme southern zones – Sow seeds in fall/winter for an early spring bloom before summer heat arrives. Provide frost protection as needed.
The timing ensures sunflowers grow and flower during optimal warm conditions and aren’t damaged by a late cold snap Stagger planting every 2-3 weeks for a prolonged harvest
Selecting the Best Site for Growing Black Oil Sunflowers
Sunflowers demand full sun exposure and fertile, well-drained soil for best growth and seed production. Choose a site that provides:
- At least 8 hours of direct sun daily
- Shelter from strong winds that can damage tall plants
- Rich organic matter like compost tilled in to a depth of 8 inches
- Loose, crumbly texture that enables roots to spread readily
- Quick drainage without retaining excess moisture
- Nearby support structures for taller varieties that can reach 12 feet
Avoid planting sunflowers where they or their predecessors grew recently to prevent disease issues.
Preparing the Soil for Planting
About 1-2 weeks before sowing, prepare beds to optimize conditions for germination and growth:
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Loosen soil to a depth of 12 inches using a shovel, spade or tiller. Break up large clumps.
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Mix in 2-4 inches of aged compost or well-rotted manure.
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Rake beds smooth, removing any rocks, debris, or clods.
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Consider adding a balanced organic fertilizer following package rates.
This deep preparation provides room for extensive root systems while bringing nutrients and organic matter closer to the surface for young plants to access.
How to Plant Black Oil Sunflower Seeds Outdoors
Sunflowers can be sown directly in the garden via a couple methods:
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Sowing in rows – Space rows 12-24 inches apart. Sow seeds 1-2 inches deep and 8-12 inches apart within rows. Narrower spacing results in one large flower per stalk while wider spacing allows side flowering branches.
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Broadcasting – Scatter seeds evenly over the prepared bed at the same depth and spacing as for rows. This creates a dense mass of sunflowers. Gently rake to cover with soil.
Other tips for direct sowing sunflowers:
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Check soil moisture and water thoroughly before sowing if dry.
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Place 2-3 seeds per spot and thin to one plant. This ensures good germination.
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Cover smaller seeds lightly with fine soil or compost; just 1/4 inch is sufficient.
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Label rows/areas with variety and sowing date for reference.
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Water gently after sowing to settle soil. Mist occasionally until sprouts emerge.
Caring for Sunflowers After Sowing Seeds
Proper sunflower care once seeds are planted will give them the best start:
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Water seedlings consistently keeping soil moist but not saturated.
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Weed carefully by hand once sprouts emerge.
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Thin to desired spacing once plants have 4-6 true leaves.
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Add a layer of organic mulch around plants to retain moisture and suppress weeds.
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Support larger plants with stakes or a trellis to prevent stem breakage from winds.
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Avoid fertilizing once plants are growing vigorously to deter pests.
With attentive watering, weeding, and protection, your sunflowers will thrive! Applying these tips for planting black oil sunflower seeds will soon provide you with a bountiful, beautiful stand. Enjoy their cheery flowers and harvest the nutritious seeds.
Customer Reviews Based on 11 reviews
All the sunflower seeds I planted have sprouted and growing well. M
Planted in a large part of pasture. Nice stalks knee high already. I’m in zone 8a. C
Best packaging around, Mylar for the seeds, and a nice thick shipping box. Z
I planted 5 acres for a dove field, and I think every seed came up. I will buy from you every year from now on, thanks K.
I plant these after I harvest potatoes. Wonderful for the soil, and beautiful.
Black Oil Sunflower Planting Information
Planting Method: transplant or direct seed
When to Plant: after last frost
Planting Depth: 1/2″
Seed Spacing: 4-6″
Row Spacing: 2-3
Days to Maturity: 110
Disease Resistance: None
Seeding Rate: 1 lb. per 5,000 square feet
How to Grow Black Oil Sunflowers
FAQ
Do black oil sunflowers come back every year?
Should I soak black oil sunflower seeds?
How do you sprout black oil sunflower seeds?
How much seeding for black oil sunflowers?
What kind of feeder for black oil sunflower seeds?
How long does it take for oil sunflower seed to germinate?
How do you plant black oil sunflower seeds?
Gardeners should also use a starter fertilizer when planting black oil sunflower seeds. This will give the seedlings the nutrients they need to get off to a good start and help ensure a successful crop. When planting the seeds, gardeners should follow the directions on the seed packet for the correct planting depth and spacing.
How much water do you need to plant black oil sunflower seeds?
When planting black oil sunflower seeds, it is important to give the soil the proper amount of water for the seeds to grow and thrive. How much water is needed depends on the type of soil, the climate, and the size of the seed bed. When planting sunflower seeds, it is best to water the soil before planting.
How long does it take to grow black oil sunflower seeds?
Of course, any of these can be grown for full-size plants and flowers that mature anywhere from 60 to 100 days from sowing, and are ready to harvest a couple of weeks after that. Small-seeded black oil sunflower seeds are available from True Leaf Market in various package sizes, from 700-seed packets and on up to 25-pound sack.
How big is a black oil sunflower?
The flower itself is usually about twelve inches across. One of the largest reasons black oil sunflowers are well known is because of their seeds. A black oil sunflower seed has a large amount of oil in it, especially compared to other sunflower seeds.
