WHEN TO SET OUTSIDE
In spring to early summer
PLACEMENT & CULTIVATION
Delphiniums are the aristocrats of the summer border, especially fine in areas where summer nighttime temperatures drop. They need a sheltered spot away from winds, a firm tall stake, and plenty of space to grow. Established plants can be thinned to a smaller number of stalks for increased air circulation. Belladonna delphiniums are more graceful in every respect and never top-heavy, so staking may not be necessary. Plant slightly above soil level and mulch to keep the soil cool (keeping away from the crown). After bloom, cut the central flowering spike down to a side shoot for additional wands of flowers. After frost clean up any plant debris and cut to the ground.
Watering Details:
Do not allow soil to dry out; water regularly, particularly during dry periods, but avoid saturated soils.
Soil pH:
Slightly acidic to slightly alkaline; if soil is very acidic, add lime before planting.
Fertilizer:
Mix in 2-4" of compost prior to planting. Top-dress existing plantings with a 1" layer of compost every spring.
Diseases & Pests:
Prevent fungal problems by planting in a location that has good air circulation. If troubles arise, treat with organic fungicides. Scout for cyclamen mite infestation that causes blackened distorted buds and use miticides if damage is noted. Slugs can damage young plants severely-use non-toxic iron based slug bait around plants.
When to Cut for Bouquets:
When 1/2 of the florets have opened
