Grower Facts

Delphinium Dasante
(Delphinium elatum)

Germination
Media
Use a well-drained, disease-free soilless medium with a pH of 5.8 to 6.2 and a medium initial nutrient charge (EC less than 0.75 mmhos/cm with a 1:2 extraction).
Sowing
Sow in a 200-cell size plug tray. In Europe, seed can be sown in 264-cell trays. A medium vermiculite cover is recommended.
Germination takes approximately 5 to 7 days.
Soil temperature: 68 to 70°F (20 to 21°C)
Light: Optional.
Moisture: Keep soil wet (level 4) during Stage 1.
Humidity: Maintain 95%+ relative humidity (RH) until radicle emergence.

Plug Production
Media
Use a well-drained, disease-free soilless medium with a pH of 5.8 to 6.2 and a medium initial nutrient charge (EC less than 0.75 mmhos/cm with a 1:2 extraction).
Sowing
Sow in a 200-cell size plug tray. In Europe, seed can be sown in 264-cell trays. A medium vermiculite cover is recommended.
Stage 1 – Germination takes approximately 5 to 7 days.
Soil temperature: 68 to 70°F (20 to 21°C)
Light: Optional.
Moisture: Keep soil wet (level 4) during Stage 1.
Humidity: Maintain 95%+ relative humidity (RH) until radicle emergence.
Stage 2
Soil temperature: 68 to 72°F (20 to 22°C)
Light: Up to 2,500 f.c. (26,900 Lux)
Moisture: Reduce soil moisture slightly (level 3) to allow the roots to penetrate into the media.
Fertilizer: Apply fertilizer at rate 1 (less than 100 ppm N/less than 0.7 mS/cm EC) from nitrate-form fertilizers with low phosphorous.
Stage 3
Soil temperature: 65 to 68°F (18 to 20°C)
Light: Up to 2,500 f.c. (26,900 Lux)
Moisture: Allow media to dry until the surface becomes light brown (level 2) before watering.
Fertilizer: Increase fertilizer to rate 2 (100 to 175 ppm N/0.7 to 1.2 mS/cm EC).
Growth Regulators: Generally not needed during plug production.
Stage 4
Soil temperature: 60 to 65°F (15 to 18°C)
Light: Up to 5,000 f.c. (53,800 Lux) if temperature can be controlled.
Moisture: Same as Stage 3.
Fertilizer: Same as Stage 3.

Growing On to Finish
Media
Use a well-drained, disease-free soilless medium with a pH of 5.8 to 6.2 and a medium initial nutrient charge.
Temperature
After transplant, provide day temperatures of 65 to 70° F (18 to 21°C) and night temperatures of 55 to 63°F (13 to 17°C) for greenhouse production. If the outside temperatures/conditions are optimal/ favorable, then 3 to 4 weeks after greenhouse production the crop can be grown outside under cold frame-type conditions to flower/finish. Optimal outside growing temperatures can be 60 to 70°F (15 to 21°C) days, and nights in low 50s°F (10 to 12°C). Delphiniums can also tolerate
lower night temperatures – in the low 40s°F (5s°C). They can flower prematurely under high temperatures, and under cooler temperatures will finish slowly. Under northwestern European conditions: This crop can also be grown at 41 to 70°F (5 to 20°C) temperature ranges. Does very well in a cool greenhouse or poly house with high light levels.
Light
No supplemental lighting is required, but keep light levels as high as possible while maintaining optimal temperatures. Under northwestern European conditions/low light conditions: For early season production, HID lights can improve plant habit and quicken the growth.
Irrigation
Avoid both excessive watering and drought. Do not allow the plants to wilt.
Fertilizer
Starting 1 week after transplant, apply fertilizer at rate 4 (225 to 300 ppm N/1.5 to 2.0 mS/cm) once a week using predominately a nitrate-form fertilizer with low phosphorus and high potassium. Maintain the media EC at 1.5 to 2.0 mS/cm and pH at 5.8 to 6.2. For constant fertilizer program, fertilizer at rate 3 (175 to 225 ppm N/1.2 to 1.5 mS/cm) can be applied while maintaining the above recommended EC and Ph ranges.
Growth Regulators
Apply foliar spray of Bonzi at 20 ppm (5.0 ml/l, 0.4% formulation) twice after transplant. First application can be done 3 weeks after transplant, and the second 2 weeks later.
Under northwestern European conditions:
Can use 1 to 2 foliar spray applications of Bonzi at 5 to 7 ppm (1.25 to 1.75 ml/l, 0.4% formulation). Tilt (propiconazool) applied weekly at 0.2 to 0.3 ml/l (250 g/l formulation) can also work.
Pinching
Pinching is not needed.
Container Size
1 gallon: 1 to 2 plants per pot
2 gallon: 3 plants per pot.
(When producing under warm season, can use 2 plants per pot for 1 gallon.)
Crop Scheduling
Sow to transplant: 5 to 6 weeks (200-cell plug)
Transplant to finish: 17 to 18 weeks (This crop time is for cool-season production. It is shorter for warmseason production and can be as early as 13 weeks from sow depending on temperatures. Though the crop time is shorter under warm season, the quality of the finished product is better under cool season conditions).
Under northwestern European conditions: 19 to 22 weeks for early season production (transplant week 5 to 8), and 14 to 16 weeks for late season production (transplant week 17). Ship this crop when the bottom one-third of the florets on the first flower spike are open to reduce the risk of flower shattering during shipping.
Common Problems
Diseases: Powdery mildew.
Garden and Landscape Information
- Dasante Blue is a first year-flowering perennial.
- Plant in full sun.
- Space plants 12 to 14 in. (30 to 35 cm) apart in well-drained soil.
- Garden height can be 28 to 34 in. (70 to 85 cm) tall.
Note: Growers should use the information presented here as a starting point. Crop times will vary depending on the climate, location, time of year and greenhouse environmental conditions. Chemical and PGR recommendations are only guidelines. It is the responsibility of the applicator to read and follow all the current label directions for the specific chemical being used in accordance with all regulations.