
Planting, Growing, and Caring for Delphinium
Types
- Belladonna Group: blue flowers native to North America; easier to grow and longer-lived than varieties in the Elatum Group (below); upright, loose, and branching perennials; secondary flower spikes extend bloom period into autumn; 3 to 4 feet tall. ‘Blue Donna’ has clear, blue flowers.
- Elatum Group: tallest varieties in shades of violet, blue, pink, and/or white; short-lived; reach 6 feet tall or more. ‘Aurora Deep Purple’ has purple flowers with a white center.
- Pacific Hybrids: 3-inch violet, blue, and pink flowers; short-lived; tolerate warm/hot climates as annuals; giant (3- to 6-foot) heirlooms and dwarf hybrids. ‘King Arthur’, 5 to 6 feet tall, has plum flowers with white centers.
I want to grow delphiniums indoors in a south-facing window with small period of shade from trees throughout the day .
A/C will be maintained to 80 degrees or less
Any chance of success?
Hello, my wife and I really like delphiniums but we hear that they are very difficult to grow here in the coastal southeast, zone 8b. Nevertheless I purchased some and planted in good, composted soil. What tips can you give me that would heighten my chances of success? Also are there any varieties that would do better than others in this area. I realize that they would be only annuals. Thank you.
I live on the southeast coast of Florida, can I grow these in the ground in partial shade?
Delphinium is technically a perennial, but it can be grown as a winter annual in Florida. Otherwise, Florida is just too hot and wet for this cool-weather plant to survive a summer season.
Delphiniums do need full Sun to grow but they prefer cool weather. So let seeds germinate in winter and the plant will bloom in early spring. Once temperatures rise in summer, the plants will fade and you’ll need to remove them.
I have 3 delphiniums (pale blue/white) growing and flowering nicely in a pot on the deck in SW Iowa. How should I winter them to see them grow and bloom in the Spring again?
As noted at the top of this page, delphiniums can be a challenge; not all grow as perennials. Many are short-lived plants. Knowing that, you could experiement: Cut them back as advised in Care above. Put them into a garage or basement and water them occasionally. Or, if you are in zone 7 or lower, lift them from the pot now and plant them (you could also plant the pot), then lift them in the spring and repot to see if they come back.
There are two conflicting suggestions on this page regarding the ideal soil pH for growing delphiniums. The intro says they are alkaline-loving, but later you say that the soil pH should be between 5.8 and 6.5. A pH of anything less than 7 is considered acidic, not alkaline (basic). Please clarify what the ideal soil pH should be for successfully growing delphiniums. Thank you!
After many years of growing Delphiniums, I
finally figured out how to protect them during our often snowy winters in
New York. And I 'm gardening in very large pots on a terrace.
I don't have to lift them or bring them inside.
I just put sand around (not on) the plants so
that even as the snow melts, even if it's a rainy
winter, they have good drainage.
You can get the sand at most hardware stores.
I now lose very few delphiniums
I currently have 5 that are two years old
and 3 that are 3-years old.
They don't last forever, but if you their roots
have lots of room to grow, they can become very
tall--even over 2 years.
Some are now six feet tall, and even in containers,
they have spread to 2-3 tall delphiniums that bloom
twice each summer.
Thanks for catching that! The information in the intro is correct: Delphiniums prefer alkaline soil, not acidic. Your soil should stay on the lower end of alkaline (between 7 and 9 pH), however.
I live in Minnesota. Last year I planted some potted Emperor Delphiniums (dark deep purple with white bee) And one or two light blues, they grew about 2ft. With at least 2 stalks. After fall was well over and just before winter began I cut all of them back. It’s finaly spring here no more snow all the snow I think has finaly melted and we have had 4 days of over 58* degrees in a row w/ no weather below 60 in the forecast.. other spring flowers are growing out of ground. Dafadiles etc. when will my DELPHINIUMS start to show some effort of growing my garden is bare.