Chocolate
Helianthus annuus
Chocolate is an ornamental flower variety prized for its deep burgundy to near-black petals and distinctive cocoa-like fragrance. Reaching maturity in 65-75 days, this heirloom cultivar produces velvety blooms that emit a subtle chocolate scent, making it a unique sensory addition to gardens. It thrives in full sun with well-draining loam soil and is notably easy to grow, ideal for both novice and experienced gardeners seeking unusual, richly-colored flowers.
Harvest
65-75d
Days to harvest
Sun
Full sun
Zones
2–11
USDA hardiness
Height
1-10 feet
Planting Timeline
Showing dates for Chocolate in USDA Zone 7
All Zone 7 flower →Zone Map
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Chocolate · Zones 2–11
Growing Details
Zone-by-Zone Planting Calendar
| Zone | Indoor Start | Transplant | Direct Sow | Harvest |
|---|---|---|---|---|
| Zone 3 | April – May | June – July | June – August | — |
| Zone 4 | March – April | June – June | June – July | — |
| Zone 5 | March – April | May – June | May – July | — |
| Zone 6 | March – April | May – June | May – July | — |
| Zone 7 | February – March | April – May | April – June | — |
| Zone 8 | February – March | April – May | April – June | — |
| Zone 9 | January – February | March – April | March – May | — |
| Zone 10 | January – January | February – March | February – April | — |
| Zone 1 | May – June | July – August | July – September | — |
| Zone 2 | April – May | June – July | June – August | — |
| Zone 11 | January – January | January – February | January – March | — |
| Zone 12 | January – January | January – February | January – March | — |
| Zone 13 | January – January | January – February | January – March | — |
Succession Planting
Chocolate sunflower throws one head per main stem, so if you want more than a single flush of blooms, you have to stagger your sowings. Direct sow every 14–21 days from April 1 through June 15 in zone 7; that cadence gets you blooms running roughly July through September. Once daytime highs are consistently above 90°F, germination turns erratic and heads come out noticeably smaller — mid-June is a reasonable cutoff.
If you started a round indoors in February or March, pick back up with direct sowing in April and stagger from there. Don't try to transplant late successions — sunflowers resent root disturbance and direct sowing catches up fast anyway.
Complete Growing Guide
Chocolate sunflowers are best started by direct sowing seeds into the garden after your last spring frost date, as they germinate quickly and prefer not to be transplanted. Plant seeds about one week after the frost date when soil has warmed to at least 50°F. If you're in a short-season climate, you can start seeds indoors 4-6 weeks before the last frost and transplant carefully into the garden once soil warms. Given the variety's range of mature heights (18 inches to 10 feet depending on growing conditions), direct sowing gives plants the best start for developing their characteristic sturdy stems.
Space seeds 6 inches apart in well-draining garden soil enriched with compost or aged manure. Plant seeds half an inch deep, pressing soil firmly over them. Chocolate sunflowers appreciate soil with neutral to slightly alkaline pH and moderate fertility; overly rich soil can produce excessive foliage at the expense of flower production. Choose a location with absolute full sun exposure—this variety needs at least 8 hours daily to develop those distinctive rich brown tops and vibrant striped yellow undersides on the petals.
Water consistently throughout the growing season, providing about one inch of water weekly through rainfall or irrigation. Young seedlings need more frequent watering until established, typically every 2-3 days in hot weather. Once plants reach 12 inches tall, they develop deep roots and become more drought-tolerant, though continued regular watering improves flower quality. Feed with a balanced fertilizer when plants reach 6 inches tall, then switch to a lower-nitrogen formula once flower buds appear to encourage blooming rather than excessive stem growth.
Watch for spider mites, which can be particularly problematic on Chocolate sunflowers during dry spells, causing stippling on leaves and reducing plant vigor. Check undersides of leaves regularly and increase humidity through foliar misting if mites appear. Powdery mildew can affect foliage late in the season, though it typically doesn't impact flower quality. The pollen-bearing flowers also attract beneficial pollinators but occasionally draw Japanese beetles—hand-pick these early in the morning if populations become heavy.
The crucial technique gardeners often overlook with Chocolate sunflowers is proper staking and support. While the plants can reach up to 10 feet tall in ideal conditions, the 4-6 inch flowers are relatively large and heavy, especially when laden with dew or visited by bees. Install stakes or sturdy cages when plants reach 2 feet tall, before they become wind-damaged. For continuous bouquet harvests throughout the season, succession plant seeds every two weeks until midsummer, ensuring blooms over an extended period rather than a single flush.
Harvesting
Chocolate reaches harvest at 65 - 75 days from sowing per Johnny's Selected Seeds. Expect 4-6" at peak. As an annual, harvest continues until frost ends the season.
Seeds are ovoid and somewhat flattened
Color: Black, Brown/Copper. Type: Achene. Length: < 1 inch. Width: < 1 inch.
Garden value: Edible
Harvest time: Fall
Edibility: Seeds are used for cooking oil, livestock feed, and as a snack food or garnish. Petals are edible and young flower buds can be steamed like artichokes.
Storage & Preservation
Fresh Chocolate flowers should be arranged in clean vases with fresh flower food and cool water (around 65°F). Keep arrangements out of direct sunlight and away from ripening fruit, which produces ethylene gas that shortens bloom life. In proper conditions, flowers last 7-10 days.
For longer-term preservation, air-dry flowers by hanging small bunches upside down in a dark, well-ventilated space for 2-3 weeks. Dried Chocolate flowers retain their striking chocolate and yellow coloring well and work beautifully in dried arrangements and craft projects.
Alternatively, press flowers between newspaper pages weighted with heavy books for 3-4 weeks to create flat, paper-thin specimens perfect for greeting cards, scrapbooking, or framed botanical art. Store dried or pressed flowers in airtight containers with silica gel packets in a cool, dark location to prevent color fading and moisture absorption.
History & Origin
Chocolate is open-pollinated, meaning seed saved from healthy plants will produce true-to-type offspring. Listed in the Johnny's Selected Seeds catalog.
Origin: Western United States
Advantages
- +Unique bicolor petals with rich brown tops and striped yellow undersides
- +Versatile stem length of 10-24 inches suits multiple arrangement styles
- +Attracts bees and pollinators, supporting garden ecosystem health
- +Quick 65-75 day maturity enables multiple plantings per season
- +Easy cultivation makes it ideal for beginner gardeners
Considerations
- -Pollen-bearing flowers may stain clothing and arrangements with dust
- -Tall varieties require staking or support in windy locations
- -Susceptible to powdery mildew in humid or poorly ventilated areas
- -Heavy seed heads can cause stem drooping near maturity
Companion Plants
Marigolds (Tagetes spp.) and nasturtiums pull the most weight here — marigolds deter aphids and whiteflies through root secretions, while nasturtiums act as a trap crop, drawing aphids onto themselves and off your sunflowers. Zinnias and cosmos bring in predatory wasps and hoverflies that keep soft-bodied pest numbers down without any effort on your part. On the harmful side, black walnut produces juglone — a compound toxic to a wide range of plants at the root zone — and fennel is broadly allelopathic, suppressing neighbors it has no business being near; give both a wide berth.
Plant Together
Marigolds
Repel aphids, whiteflies, and nematodes while attracting beneficial insects
Nasturtiums
Act as trap crops for aphids and cucumber beetles, protecting chocolate cosmos
Zinnias
Attract pollinators and beneficial predatory insects while providing complementary colors
Cleome
Attracts beneficial insects and provides vertical structure without competing for nutrients
Sweet Alyssum
Ground cover that attracts beneficial wasps and hoverflies for pest control
Lavender
Repels moths, fleas, and mosquitoes while attracting pollinators
Borage
Attracts pollinators and beneficial insects while improving soil through deep taproot
Cosmos
Similar growing requirements and attracts beneficial insects without competition
Keep Apart
Black Walnut
Produces juglone toxin that inhibits growth and can kill chocolate cosmos
Fennel
Allelopathic properties inhibit growth of most flowering plants including cosmos
Eucalyptus
Releases allelopathic compounds that suppress growth of nearby flowering plants
Troubleshooting Chocolate
What you'll see, why it happens, and what to do about it.
Seedling stems pinched off at soil level, often overnight
Likely Causes
- Cutworms (Agrotis spp.) — fat, curl-up larvae that hide in the top inch of soil during the day
- Slugs, especially in wet springs with heavy mulch
What to Do
- 1.Press a cardboard or aluminum collar 2 inches into the soil around each stem at transplant time
- 2.Scatter iron phosphate bait (Sluggo) around the base if you're seeing slime trails
- 3.Dig around the base of cut stems — if you find a gray-brown grub, drop it in soapy water and check neighboring plants
White powdery coating on leaves, usually starting mid-summer on mature plants
Likely Causes
- Powdery mildew (Erysiphe cichoracearum) — fungal, spreads in warm days with cool nights and poor airflow
- Crowded spacing under 12 inches that traps humidity between stems
What to Do
- 1.Strip and trash badly coated leaves — don't compost them
- 2.Spray remaining foliage with a diluted solution of 1 tablespoon baking soda per gallon of water, or a neem oil product at label rates
- 3.Next season, hold spacing to at least 12 inches and avoid overhead watering in the evening
Leaves skeletonized — tissue eaten away leaving only the veins — on plants 12–24 inches tall
Likely Causes
- Sunflower beetle (Zygogramma exclamationis) larvae, which feed in clusters on the upper leaf surface
- Japanese beetle (Popillia japonica) adults, which work from the top down
What to Do
- 1.Pick beetles off by hand into a bucket of soapy water in the early morning when they're sluggish
- 2.Apply Spinosad (OMRI-listed) to the foliage if populations are heavy — repeat every 7 days
- 3.Check leaf undersides for egg clusters and crush them before they hatch
Flower head drooping or turning toward the ground before seeds develop, with the stem just below the head gone soft
Likely Causes
- Sunflower moth (Homoeosoma electellum) larvae boring into the stem just behind the flower head
- Sclerotinia stem rot (Sclerotinia sclerotiorum) — rots the pith from the inside, worse in wet conditions
What to Do
- 1.Cut the affected stem 6 inches below the soft section and split it open — a small caterpillar means sunflower moth; dispose of the cutting in the trash, not the compost
- 2.If the pith is black and mushy with no insect present, pull the whole plant and rotate that bed away from sunflowers for at least 3 years
- 3.Switch to drip irrigation once heads are forming — keeping the stem neck dry cuts Sclerotinia risk considerably
Frequently Asked Questions
How long does Chocolate flower take to grow from seed to bloom?▼
Is Chocolate flower good for beginners?▼
Can you grow Chocolate flowers in containers or pots?▼
When should I plant Chocolate flower seeds?▼
Why are my Chocolate flowers not blooming?▼
How long do Chocolate flowers last as cut flowers?▼
Growing Guides from Wind River Greens
Where to Buy Seeds
Sources & References
External authority sources used in compiling this guide.
- BreederJohnny's Selected Seeds
See the Methodology page for how this data is sourced, what's AI-assisted, and known limitations.