Take basal cuttings
We propagate delphiniums by taking basal stem cuttings. Scraping soil a few centimetres down from the crown reveals embryonic shoots emerging from thicker parent plant tissue. Take cuttings when shoots are about 8-10cm long. Use a sharp knife and ensure thicker, basal material from the union with the parent is retained. Remove all but one or two leaves and clear the lower part of the stem of any protruding plant material, which could cause rot to set in. Make a final, straight cut through the thicker, basal tissue before inserting into a gritty or free-draining growing medium. Water and cover to retain moisture.