To start, seeds can be sown from March to April or planted outside in May to June where they will flower through summer.
Delphiniums prefer a moist but well-drained spot with full sun. However, they won’t grow well in heavy soil and wet conditions. Therefore if the borders have these conditions, add grit to aid drainage.
Then, plant them in place at the same height as they were in the pot before firming in place and watering in well.