CALLISTEPHUS CHINENSIS, ASTER Starlight

TECHNICAL INFORMATION

Life Cycle:Annual

Familiy, Origin:Asteraceae, China, Japan

Sitelocation:Full sun - partial shade

Garden Height:20 cm 7,87 inch

Flower Size:9 cm 3,54 inch

Natural flowertime:August - September

Crop Time:Plug crop: 7-8 weeks; Flowering pots: 14-15 weeks

Seed Form:Raw Seed

Seed Count:450 K/g

Sowing Time:January for flowering in May (artificial long days); May for flowering in September (natural day length); July for flowering in January (artificial long days).

Sowing Method:3-5 seeds per plug, sowing in final pots is possible

Germination:7-21 days at 15- 21 °C, in media with low soluble salt levels and pH: 6.0-6.5. Before sowing treat substrate with fungicide. Cover seed with vermiculite, sand or substrate after sowing. Keep soil slightly moist but not wet. High temperatures inhibit the germination.

Plug Culture:From Stage II* reduce the soil moisture, but the plug should not dry out and reduce the temperature to 15-17 °C. Do not let soluble salt level rise above 0,75 EC. Start fertilization at 50-75 ppm nitrogen in a well balanced formula. During Stage III and Stage IV fertilization levels can be increased to 100-150 ppm.

Growing On:3-4 weeks after sowing transplant 1 plant into a pot (9-10 cm), 2-3 plants into a big pot (11 cm) or 3-4 plants into a bigger pot (12-13 cm). Plant cut flowers in 15-25 x 15-25 cm space and use nets to keep the stems upright.

Media:Use a well-drained, growing substrate with 20-30 % clay, 1-1,5 kg/m3 complete balanced fertilizer, 0-2 kg/m3 slow release fertilizer (3-6 months), iron-chelate, micronutrients, pH: 6.0-6.5. Use a sterile medium and sterile pots/containers as preventative measures against Fusarium and Verticillium. Field: sandy loamy soils with good drainage and moderate nutrition levels. Standard fertilization: 80-100 g/m2 slow release fertilizer. Disinfect the soils in greenhouse before planting.

Photoperiod / Light:Long day plant. The long day support the flower initiation, vegetative growth and branching. The short day support the flower development and inhibit the vegetative growth. When arising seedlings need 14-16 h lighting for a minimum of 4 weeks (plant height: 38-45 cm). During natural short days use supplemental lighting. Night interruption (4 h) is possible. After flower bud is initiated short days may accelerate flower development and shorten crop time. Plants grown only in short days form a leaf rosette and no flower at all.

Temperature:Grow at 12-15 °C. Callistephus do not grow temperatures below 8 °C and do not tolerate frost. The lower the temperature, the better the plant habit but onset of flowering will be a little delayed. Lower temperatures combined with short days cause the development of a leaf rosette and short stems.

Fertilization:Moderate-high fertilization levels are required. Fertilize the crop weekly with 100-150 ppm nitrogen (at 2 kg/m3 slow release fertilizer in substrate), using a potassium balanced fertilizer (N: K2O-ratio: 1:1,5). Avoid high ammonium and high nitrogen levels. High nitrogen levels will cause smooth stems. Prevent magnesium deficiency by applying magnesium sulphate (0,025 %) 1-2 times and in case of iron deficiency apply iron-chelate for 1-2 times. Field: N min soil value: approximately 150 g/m2.

Cultural Hints:Dry, light and airy cultivation. After planting treat substrate and soil with fungicide against Phythophthora and Fusarium. Disinfect the soils in greenhouse before planting and rotate the beds yearly.