The irresistible allure of delphiniums

Delphiniums, 'Magic Fountains' series                                                       pkdon50/Flickr

True confessions -- I can't see photos of English gardens blooming in June without serious lust in my heart for the stately delphiniums.

There they stand, tall and cool, with tightly packed spires of the bluest blue blossoms in Christendom. Close up, the flowers have a powdery coating that makes the color almost iridescent. Their contrasting centers, known as “bees,” can be coal-black or white, adding just another irresistible feature to a knockout flower.

Delphiniums don’t lie around a gardener’s ankles like a clutch of pinks, for instance, or swath of lily-of-the-valley. No, at up to 6 feet, they look a fully grown gardener in the eye, or even tower overhead with a snobbish air. These are plants with real stature and undeniable cachet.

And there’s that blue, true blue, the rarest color in the garden.

Having some delphiniums of one’s own is the secret dream of many who come under the influence of those very beautiful English gardening books with their very beautiful photographs. But there’s a catch — isn’t there always?

Most delphiniums want to live where the atmosphere is perpetually damp and where a day with temperatures creeping toward 80 degrees is considered unnaturally, unacceptably hot. They want to be someplace like the British Isles, the Pacific Northwest or New Zealand, source of some of the latest and jazziest hybrids.

Delphiniums of the traditional sort flag in the hazy, hot and humid nonsense that is the essence of summer in New Jersey and points south along the Eastern seaboard. They just don't do sweltering. They prefer to avoid brutally hot days and sticky nights.

So, forget those venerable and aristocratic hybrids bred since the early 1900s by the English nursery Blackmore and Langdon. Forget their New World equivalent, the Pacific Giants raised in California by Frank Reinelt in the 1930s. If these are what you simply must have, I'm afraid you'll have to move.

On the other hand, there are heat-tolerant delphiniums for our climate if you care to lower your sights just a bit. These aren't the stately, one-stem wonders fat with flowers, but rather delphiniums of a shrubbier, shorter kind with looser spikes of flowers.

'Bellamosum' in the author's garden

Possibly the most obscurely famous one is `Connecticut Yankees,' developed by the artist and photographer Edward Steichen (1879-1973).

When he wasn't inventing a uniquely American style of photography or pioneering the use of color film, Steichen was busy gardening at his Connecticut home, and delphiniums were his passion. In 1936, when he assumed the presidency of the American Delphinium Society, he also mounted an exhibit at the Museum of Modern Art featuring his fabulous delphiniums.

These were notable as a group for being the first genetically altered flowers to be shown as art. Steichen not only practiced selective breeding in the ordinary way, he also dosed his subjects with colchicine, a drug that altered the plant's genetic makeup — a technique still used to prompt plant mutations.

`Connecticut Yankees' grow to about 30 inches and are quite bushy and free-flowering. They don't require the meticulous staking that is part and parcel of growing the taller, traditional kinds, although all delphiniums are a finicky lot, prone to a double handful of pests and diseases.

The other way to go is with the species: Delphinium x belladonna (light blue) and the subspecies Delphinium x belladonna ‘Bellamosum’ (dark blue). It is the latter that I have been growing with good success — providing one fends off the slugs when the shoots are small and accepts the fact that these are short-lived plants that need to be replaced every few years.

The big surprise for me was the length of bloom I've gotten from my bellamosums, as in from June through the end of August. True, the shrubby plants were kind of lax and floppy last year, but who failed to give them the support they deserved?

This year, I already have my first flowers from a vigorous self-sown seedling that by now has companions from Lazy S's Farm and Nursery in Virginia, among the few East Coast mail-order sources to carry 'Bellamosum.'

It's important to know that delphiniums are greedy feeders and want a soil on the alkaline side. I prepped their bed with lots of humus mixed with composted manure, and laced the patch with wood ashes, an alternative to agriculture lime and half its strength.

I also gave them plenty of room to promote good air circulation and fend off powdery mildew, and provided each with a grow-through support to keep its many shoots standing upright. (Are you paying attention to the amount of fussing required, even by these?)

Bottom line: I'm not mooning over those veddy British delphiniums that don't want to live with me here in the déclassé "colonies." When my species delphiniums break out their dreamy, deep blue blossoms, I think they will do me nicely.