English Delphiniums - Knowledgebase Question

Bay City, Mi
Question by tomdclements
January 15, 2010
I came across some very vague information about English Delphiniums. I cannot find any species information about them and contacted some local nurseries about them and they nor there suppliers give any information more than what I had. There is a Enlish Delphinium club in Alaska, but not much information. I know thet're not Larkspurs. Have you any information about them? Only information I could get was on the internet

Answer from NGA
January 15, 2010


English Delphiniums are Delphinium elatum, the most commonly grown delphiniums. Delphinium's majestic bloom spikes are a mainstay of many summer gardens. Flower color covers the full range of blues and purples, and you'll find cool pinks, cream, and white as well. Individual blooms are flat, to 2 inches across, borne in narrow, upright spikes. Leaves are dark green and deeply lobed. The tall-growing cultivars of D. elatum are most widely grown; they form 1- to 2-foot-wide clumps and send up 5- to 6-foot flower spikes.

Delphiniums prefer cool, moist summers and chilly but not excessively cold winters. They need rich, porous, nonacid soil; if soil is acid, amend it to neutral before planting. Also work in organic matter and a high-phosphorus fertilizer. When new shoots appear in spring, remove all but the two or three strongest and apply a complete fertilizer. Stake flower stalks early. Cut back stalks after bloom, leaving foliage at the bottom; when new stalks emerge, fertilize again to encourage fall bloom.

Even under ideal conditions, delphiniums are usually short lived; dividing them each year in spring may prolong their lives. If grown outside their preferred climate, they're best treated as annuals. Plant in fall in mild-winter zones, and just after frost danger is past where summers are hot.

Besides cultivars of D. elatum, tall delphiniums include the Pacific Hybrids, with flower spikes up to 7 feet.

Hybrids of D. belladonna, such as 'Bellamosum', are somewhat hardier and less prone to disease than other delphiniums. Don't pinch or disbud these; just let them grow as they will. Their blossom spikes are shorter but more numerous than those of D. elatum.

Chinese delphinium (D. grandiflorum) is somewhat more forgiving of less-than-ideal conditions than D. elatum, though it does have the same soil and climate needs. It's a many-stalked plant that grows just 1 1/2 to 2 feet tall, bearing flowers in blue shades.

Hope this information sheds some light on the plant!

You must be signed in before you can post questions or answers. Click here to join!

« Return to the Garden Knowledgebase Homepage

Member Login:



[ Join now ]

Today's site banner is by TBGDN and is called "Irises 2017"