Mimulus Maximus Cultural Information

Plug Production

Sowing/Media: Use a well-drained, disease-free, peat-based plug medium with a pH of 5.5 – 5.8 and EC <0.75 mmhos (saturated paste). Sow pelleted seed when possible, and do not cover seed.

Germination (Stages 1 and 2): Keep medium uniformly moist, but not saturated. Soil temperature should be 65 – 68 F. Keep light levels <1500 footcandles. Germination time is 5 – 7 days.

Stage 3: Soil temperature should be 62 – 65 F. Use a good wet/dry moisture cycle, but avoid wilt. Light levels should be around 3000 footcandles. Mimulus is a long-day plant, and will respond to night-interruption lighting after first true leaf is visible. If growing under HID lights, flowering may occur before transplanting. Feed every other watering with 100 – 150 ppm N from 17-5-17, 15-5-15, or 13-2-13. Keep media pH 5.5 – 5.8 and media EC 1.0 – 1.5 mmhos (saturated paste).

Stage 4: Soil temperature can be lowered to 60 – 62 F. Maintain light levels around 3000 footcandles, and provide long days with night-interruption lighting. If using HID lights, you will have flowers evident before transplanting.

Plant Growth Regulators: No plant growth regulators needed, as plug crop time is short and flowering occurs quickly with long days.

Crop Time: 3 – 4 weeks for 512 plugs, 4 – 5 weeks for 288 plugs, depending on temperature and light.

Common Problems: Root rots, wilting, too early flowering – using HID lights

Growing on to finish

Container Size: Cell packs to 4-inch pots

Media: Transplant into a well-drained, disease-free, peat-based growing mix with pH of 5.5 – 5.8 and EC <1.5 mmhos (saturated paste).

Temperatures: Keep soil temperatures on the cool side (50 – 60 F) if possible.

Light: Keep light levels around 3000 footcandles, and use shade if needed when growing with higher temperatures. If plugs were not lit during short days, provide 3 weeks of long days with night-interruption lighting.

Irrigation and Fertilization: Practice a good wet/dry moisture cycle, but avoid wilt. Feed 1 – 2x/week with 150 ppm N from 17-5-17, 15-5-15, or 13-2-13. Keep media pH 5.5 – 5.8 and media EC 1.5 – 2.0 mmhos (saturated paste).

Plant Growth Regulators: No plant growth regulators needed. Use sprays of B-Nine (2500 ppm) when growing during warm weather. If flowering occurs too early, plant growth will need to be pushed.

Common Problems: Root rots, thrips, flowering too early – growing plugs under HID lights using daylength extension, flowering delayed – not lighting during short days.

Crop Time: 4 – 5 weeks, depending on plug and container size, temperature, and daylength.