Delphinium Planting and Care Guide
Quick Facts About Delphinium
Delphiniums may be considered to be somewhat old-fashioned, but there's nothing like their majestic form and color to offer a beautiful display. The flowers are showy while the foliage is lacy and softens the background of the flower bed. They are great for cutting and can last 6 days or more in a vase, and bees and butterflies will enjoy visiting the gorgeous blooms.
Delphinium seeds do best with a cold treatment, so the seeds can be directly sowed outdoors in late winter/early spring when frosts are still expected. Or, after time in the refrigerator, start the seed indoors 6 - 8 weeks prior to the end of frost season.
Delphiniums do best in cold climates. They like full sun or partial shade and soil that drains well and is kept moist. Nutrient rich soil is very important.
How to Plant Delphinium
- For indoor sowing, mix the Delphinium seeds in with moistened soil or peat moss and place this in the refrigerator for a week
- After the period of cold, fill trays or peat pots with moistened seed starting soil
- Press the Delphinium seeds into the soil and lightly cover
- Ideal temperature for Delphiniums to germinate is 65 - 75F
- Keep the soil moist but not soggy
- Once there are seedlings, place them under grow lights for the best growing results
- Once outdoors temperatures are warming and no more frosts are expected, harden the Delphiniums off for 7 - 10 days
- If needed, at the time of transplanting, amend the soil with compost to improve the texture of the soil to make it lighter and drain better
- Or, in the early spring, work the soil to a depth of several inches
- Add compost to improve the soil
- Sow the Delphinium seeds on the surface and lightly cover with soil
- Keep the area constantly moist for germination
Care And Maintenance
- Water well when the Delphinium plants are growing
- Provide stakes or other support if needed
- Mulch around the base of the plant to suppress weed growth and help to retain moisture
- After blooming, cut the spikes down to 4 or 5 inches in height and reduce watering
- Provide pesticide for slugs