Aster (callistephus) Milady 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). Cover seed with coarse vermiculite after sowing.

Germination (Stages 1 and 2): Keep medium uniformly moist, but definitely not wet! Soil temperature should be 70 – 72°F. Keep light levels <1500 footcandles. Germination time is 7 - 10 days.

Stage 3: Soil temperature should be 65 – 68°F. Use a good wet/dry moisture cycle, but avoid keeping too wet. Light levels should be around 3000 footcandles. No supplemental lighting is needed. Feed every other watering with 100 – 150 ppm N from 15-5-15, 17-5-17, or 13-2-13. Keep media pH 5.5 – 5.8 and media EC 1.5 – 2.0 mmhos (saturated paste).

Stage 4: Soil temperature can be lowered to 60 – 62°F. Maintain light levels around 3000 footcandles, use a wet/dry moisture cycle, and feed mainly with 13-2-13 as needed.

Plant Growth Regulators: Use sprays of B-Nine (2500 ppm) or A-Rest (2 – 7 ppm) as needed. Some growers will use an early sprench of A-Rest at 1 – 3 ppm before cotyledons have opened to prevent early stretch and floppiness.

Crop Time: 4 – 5 weeks for 512 plugs, 5 – 6 weeks for 288 plugs, depending on temperature and light levels.

Common Problems: Pythium, Fusarium, lower yellow leaves – lack of feed

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 temperature 65 – 68°F for rooting out, then lower to 62 – 65°F for growing on.

Light: Keep light levels 3000 – 5000 footcandles. Use shade when temperatures are higher than desired.

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

Plant Growth Regulators: Use sprays of B-Nine (2500 ppm) or A-Rest (3 – 7 ppm) as needed. If managing moisture and feed levels properly, no plant growth regulators will be needed.

Common Problems: Root rots, Botrytis, aphids, thrips, lower yellow leaves – too low feed.

Crop Time: 6 – 8 weeks, depending on plug and container size, temperature, and light levels.