Delphinium Plants

You can plant delphiniums year-round, but the best planting time is in spring or early summer, which gives the plant time to get established before the colder months.

Delphiniums will do best in a sheltered position with full sun (at least six hours per day) and in well draining soil.

Delphiniums need regular watering throughout the growing season in spring and early summer, especially when the weather is dry or hot. Be careful not to overwater them though, as they can suffer from root rot if they get waterlogged.

Delphiniums have tall, slender stems with large flowers, so they usually need staking or support to stop them from flopping over. Use plant sticks or bamboo canes and tie the stems to them with soft twine or plant ties.

Delphiniums benefit from a feed with general purpose fertiliser in early spring as their new growth begins. A mulch of compost or well rotted manure at this time will also help to boost nutrients.

If your delphiniums start to look a bit crowded, you can divide them every few years in early spring or autumn. Dig up the clumps and carefully separate them into smaller sections, making sure each part has plenty of healthy roots, then replant them where you want.

Deadheading encourages delphiniums to produce more blooms - to do this, simply snip off the faded flowers with scissors or pruners as soon as they start to fade.

Delphiniums are hardy plants, but in very cold winters mulching around the base of the plants in late autumn will protect the roots from frost. Cut back the dead foliage in late autumn or early spring, but leave some stems intact to provide some protection for the crown.