Ageratum Blue Horizon
Life Cycle: Annual
Use: Cut flower, filler, massing flower, pollinator gardens
Height: 60–90 cm
Spacing: 20–30 cm between plants
Transplant to finish: 12–16 weeks
Transplant carefully after the last frost. Pinching young plants encourages branching and increases stem production.
Photoperiod: Facultative long-day—flowers more quickly under longer day lengths.
Exposure: Full sun (6+ hours daily)
🌾 Soil & Fertility
Soil: Well-drained, fertile loam or quality potting mix
pH range: 6.0–7.0
Fertilizer: Apply a balanced fertiliser every 2–3 weeks during active growth.
Avoid excessive nitrogen, which promotes leafy growth at the expense of flowers.
💧 Watering
Keep soil consistently moist during establishment.
Once established, water deeply when the top 2–3 cm of soil becomes dry.
Avoid prolonged waterlogging, as this can lead to root diseases.
🧼 Hygiene & Disease Prevention
Provide good air circulation and avoid overhead watering late in the day to reduce disease pressure.
✂️ Harvesting & Post-Harvest
Harvest stage: Cut when flower clusters are fully coloured and approximately one-third to one-half of the florets are open.
Stem length: 50–80 cm ideal for bouquets.
Post-harvest:
Strip lower leaves.
Place immediately into clean water with floral preservative.
Vase life is typically 7–10 days with proper care.