Phlox 21St Century F1 Mix Seeds

Grow a full, compact mound of colourful annual phlox with vigorous side branching and rounded five-petalled blooms. Phlox 21st Century F1 Mix is primed Phlox drummondii seed for sunny beds, borders and well-drained patio containers.

Ready to fill a sunny bed or pot with compact phlox colour? Follow our step-by-step Phlox Grow Guide for 21st Century F1 Mix for primed-seed storage, dark germination, transplanting, regional timing and care.

Quick Grow Facts

• Plant Type: F1 hybrid annual
• Scientific Name: Phlox drummondii
• Series: 21st Century F1 Mix
• Seed Form: Primed seed; do not soak or re-prime
• Pack Sizes: 25 and 250 primed seed; live stock varies
• Storage: Keep cool and dry, ideally near 5°C; let the sealed packet reach room temperature before opening; use promptly and follow any lot-specific use-by date
• South African Sowing Time: Autumn in mild, frost-free districts; protected late-winter sowing for frost-prone interiors
• Position: Full sun in cool weather; light afternoon protection where heat is severe
• Sow Depth and Light: Cover about 3 mm with coarse vermiculite or fine mix; darkness is required during germination
• Germination: Breeder benchmark 3–5 days at 18–21°C; allow the packet’s 14–21-day home-tray window
• Medium and Moisture: Fine, clean, low-salt, free-draining mix; keep evenly moist and aerated, never saturated
• Pretreatment: None; the seed is already primed
• Method: Tray sowing is recommended; direct sow only in cool, frost-free, weed-free soil where moisture can be controlled
• Transplanting: Move a sturdy root-held plug after about 4–5 weeks and harden gradually for 5–7 days
• Spacing: Packet spacing 20 × 20 cm; allow 25–30 cm where airflow is important
• Growth Form: Compact, mounded and strongly branched
• Height and Spread: About 25 cm high and 25 cm wide
• Support and Pinching: No support or pinching normally needed
• Flowering: Begin checking from about 70 days; allow 70–90 days from sowing under suitable conditions
• Use and Safety: Ornamental display; do not eat packet seed or flowers

Why Grow This Variety

• F1 vigour supports fast, uniform growth and early flowering.
• Strong lateral branching creates a full, rounded display.
• Compact plants suit beds, borders and containers.
• The mixed palette provides colour through the cool growing season.

Garden Uses

Plant in a sunny border, massed bedding display or container with drainage holes. Space more generously in humid gardens so air can move through the compact mound.

Growing Notes

• Keep unopened or resealed primed seed cool and dry; warm the sealed packet to room temperature before opening.
• Sow one seed per cell, cover 3 mm and keep at 18–21°C in darkness until shoots emerge.
• Move seedlings into bright light immediately after emergence and grow on near 16–18°C.
• Keep moisture even without severe wilting or saturation; annual phlox is sensitive to high salts.
• Transplant before plugs become root-bound, then water at soil level and maintain airflow.

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