ProCut® Bicolor
Helianthus annuus
Photo: David L. Van Tassel( Desmanthus4food ) The Land Institute · Wikimedia Commons · (CC BY-SA 3.0)
Tall with strong stems. 4-6" blooms. Pollenless. Single stem.
Harvest
50-60d
Days to harvest
Sun
Full sun
Zones
2–11
USDA hardiness
Height
1-10 feet
Planting Timeline
Showing dates for ProCut® Bicolor in USDA Zone 7
All Zone 7 flower →Zone Map
Click a state to update dates
ProCut® Bicolor · Zones 2–11
Growing Details
Zone-by-Zone Planting Calendar
| Zone | Indoor Start | Transplant | Direct Sow | Harvest |
|---|---|---|---|---|
| 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 | — |
| 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 | — |
Succession Planting
ProCut Bicolor takes 50–60 days from direct sow to harvest, which makes it well-suited for succession planting through the warm season. In zone 7, direct sow your first round around April 1 once soil temps hit at least 55°F, then follow up every 14–21 days through late June. That cadence gives you continuous cuts from late June into early fall without a glut all at once.
Stop sowing by early July in most zones — seeds started after that will be racing against the first frost, and late-season heat also tends to produce smaller heads with shorter vase life. If you want fall color, make your last sow around July 1 and plan for harvest in mid-September, counting back 60 days from your local first-frost date to confirm the timing works.
Complete Growing Guide
ProCut® Bicolor sunflowers thrive when started directly in the garden after your last frost date has passed and soil has warmed to at least 50°F. While you can start seeds indoors 4–6 weeks before your final frost, these vigorous plants prefer direct sowing since they develop long taproots that resent transplanting. Simply push seeds about three-quarters of an inch deep into warm soil, spacing them 12–18 inches apart in a location that receives full, unobstructed sunlight for at least eight hours daily. The stronger the light, the straighter and more robust the single stems will grow, which is essential for cut flower quality.
Prepare your soil by incorporating compost or well-rotted organic matter to improve drainage and nutrient content. ProCut® Bicolor isn't particularly fussy about soil pH but performs best in well-draining ground that won't waterlog after heavy rains. Consistent moisture is important during germination and the first few weeks of growth, but once established, these sunflowers are quite drought-tolerant. Water deeply and less frequently rather than with shallow, daily sprinkles—this encourages deep root development. As plants mature, reduce watering frequency unless you're experiencing genuine drought conditions.
Feed ProCut® Bicolor with a balanced, slow-release fertilizer at planting time, then apply a light nitrogen boost when plants reach about 12 inches tall to support vigorous stem development. Avoid excessive nitrogen later in the season, which can weaken stems and reduce flower quality. Monthly applications of a diluted liquid fertilizer work well for container-grown specimens, though garden-planted varieties rarely need more than one or two supplemental feedings.
Watch carefully for sunflower moths and stem weevils, which specifically target sunflower stems and can devastate the tall, single-stem architecture that makes ProCut® Bicolor so valuable for cutting. Inspect stems weekly, particularly around the base and leaf nodes. Japanese beetles may also appear; handpick them early in the morning when they're sluggish. Spider mites occasionally trouble these plants in hot, dry conditions—mist foliage regularly to discourage them.
The one mistake most gardeners make with ProCut® Bicolor is overcrowding. These plants need generous spacing not just for airflow and disease prevention, but because closer spacing creates competition that results in thinner, weaker stems unsuitable for cutting. Stick to your spacing guidelines even if it feels wasteful initially.
Succession planting every two weeks from late spring through midsummer ensures continuous blooms throughout your cutting season. At 50 days to maturity, staggered plantings provide flowers from mid-summer through fall. Once buds form, provide gentle support with stakes if you live in a windy area, protecting your investment in these spectacular, long-stemmed pollenless blooms.
Harvesting
ProCut® Bicolor reaches harvest at 50 - 60 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
ProCut® Bicolor cut flowers should be stored in a cool location, ideally 34-40°F with 80-90% humidity—a refrigerator is best for extending vase life. At room temperature, they last 7-10 days; refrigerated, they can last 2-3 weeks. Keep stems submerged in fresh, clean water and change water every 2-3 days. Preservation methods include: (1) Glycerin conditioning—mix 1 part floral preservative with water to nourish stems and enhance longevity; (2) Drying—hang bundles upside down in a cool, dark, well-ventilated space for 1-2 weeks to create long-lasting dried arrangements; (3) Pressing—place blooms between newspaper under weight for 2-3 weeks to preserve color and create botanical specimens.
History & Origin
ProCut® Bicolor is an F1 hybrid developed through controlled cross-pollination. Listed in the Johnny's Selected Seeds catalog.
Origin: Western United States
Advantages
- +Tall strong stems ideal for professional cut flower arrangements
- +Large 4-6 inch bicolor blooms create striking visual impact
- +Pollenless flowers reduce mess and allergen concerns indoors
- +Quick 50-60 day maturity allows rapid succession plantings
- +Easy cultivation makes it suitable for novice growers
Considerations
- -Tall plants require staking or support in windy conditions
- -Bicolor varieties sometimes show color inconsistency between plants
- -Susceptible to powdery mildew in humid growing environments
Companion Plants
Marigolds, zinnias, and cosmos are the most useful companions in a cutting-flower bed. Marigolds (Tagetes spp.) deter aphids and whiteflies through root exudates and scent — plant them as a border 12 inches out from your sunflower rows. Zinnias and cosmos draw in parasitic wasps and hoverflies that prey on caterpillars and aphid colonies; they also fill gaps in a mixed bouquet, which is a practical bonus if you're cutting for market or a vase. Sweet alyssum planted densely at the row base attracts ground beetles that eat fungus gnats and small soil pests.
Fennel is the one to avoid near any sunflower bed. It releases allelopathic compounds from its roots that stunt neighbors, and Helianthus annuus is sensitive enough that you'll see the difference — keep fennel in its own container or a bed at least 3 feet away. Black walnut trees are a harder problem: they produce juglone, a soil toxin that accumulates in the root zone and can suppress sunflower growth entirely. If you have one on the property, don't trial ProCut Bicolor anywhere the canopy drip line reaches.
Plant Together
Marigolds
Repel aphids, whiteflies, and nematodes while attracting beneficial insects
Zinnia
Similar growing conditions and bloom time, attracts pollinators and beneficial predators
Nasturtiums
Act as trap crop for aphids and cucumber beetles, repel squash bugs
Cosmos
Attract beneficial insects and pollinators, provide complementary colors and heights
Sweet Alyssum
Ground cover that attracts hover flies and parasitic wasps for pest control
Cleome
Tall backdrop plant that attracts butterflies and doesn't compete for resources
Basil
Repels aphids, thrips, and flies while attracting beneficial pollinators
Petunias
Repel aphids, tomato hornworms, and squash bugs while providing color contrast
Keep Apart
Black Walnut Trees
Release juglone toxin that causes yellowing, wilting, and death in sensitive plants
Fennel
Allelopathic properties inhibit growth and germination of nearby flowers
Eucalyptus
Releases allelopathic compounds that suppress growth of most flowering plants
Troubleshooting ProCut® Bicolor
What you'll see, why it happens, and what to do about it.
Seedling stems pinch off at soil level, plants topple over within the first 2 weeks after germination
Likely Causes
- Damping off (Pythium or Rhizoctonia spp.) — soil-borne fungi that thrive in cold, waterlogged growing media
- Overwatering combined with poor drainage in seed trays
What to Do
- 1.Let the top half-inch of soil dry out between waterings — sunflowers don't need to stay constantly moist
- 2.If starting indoors, use a sterile seed-starting mix, not garden soil
- 3.Increase airflow with a small fan set on low; this dries surface moisture and physically strengthens stems
Leaves develop irregular pale or silvery streaking, sometimes with tiny black specks on the undersides, about 3–4 weeks after transplant
Likely Causes
- Western flower thrips (Frankliniella occidentalis) — common on open-petaled flowers and tender new growth
- Thrips feeding causes cell damage that shows up as that characteristic silver stippling
What to Do
- 1.Check undersides of leaves with a hand lens — thrips are tiny (under 2mm) but visible
- 2.Spray with spinosad-based insecticide in the early morning before pollinators are active; repeat every 7 days for 2–3 applications
- 3.Yellow sticky traps hung at plant height can confirm the infestation and catch adults
Mature flower heads develop gray-brown fuzzy patches on petals or the back of the head, especially after a wet stretch
Likely Causes
- Botrytis blight (Botrytis cinerea) — a fungus that moves fast in humid, still air once flowers open
- Heads left standing in dense plantings without airflow are the most vulnerable
What to Do
- 1.Cut affected blooms immediately — Botrytis spreads by spore release and any disturbance sends them airborne
- 2.Space plants at least 18 inches apart (24 is better for cut-flower rows) to keep airflow moving through the canopy
- 3.Harvest ProCut Bicolor at the 'green center' stage — just as petals open but before the disk fully matures — which gets the bloom out of the field before Botrytis can establish
Frequently Asked Questions
How long do ProCut® Bicolor cut flowers last in a vase?▼
Is ProCut® Bicolor a good choice for beginners?▼
Can you grow ProCut® Bicolor in containers?▼
When should I plant ProCut® Bicolor seeds?▼
What makes ProCut® Bicolor different from other cut flower varieties?▼
How should I prepare and condition ProCut® Bicolor flowers after cutting?▼
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.