Not long ago I was chatting with a Highly Distinguished Gardener about delphiniums. Not the demure species or winsome little larkspurs, mind you—no, we were talking about the big, buxom hybrids that tower over the June and July garden. “They’re not fashionable, you know,” she said with a sigh. “Still, I do love them.” I’m afraid that Highly Distinguished was right: delphiniums aren’t fashionable, and it’s not hard to see why. For one thing, they make the most ego-inflamed opera diva look like Miss Congeniality. In their infancy, they have to be protected from slugs. As they grow, they have to be staked, well and carefully, and even then a downpour or a gust of wind can send them toppling. Their soil must be moist and dark, like rich fudge cake, and they’re ravenous as unfed cats. When they’ve finished blooming, they look frightful and have to be cut to the ground.
And yet, and yet, and yet. If they were to disappear completely from our gardening repertoire, what a sad day it would be. There are plenty of wonderful blue flowers, but where else can we find such a concentration of pure, glorious blueness? It’s almost like a drug. Looking at a stand of delphiniums, drinking in that dazzling color, you feel a visceral happiness—blue bliss courses through your veins like super-oxygenated blood.
And that, fellow gardeners, is why delphiniums should—must—be grown. I don’t dispute that it is, perhaps, a quixotic undertaking, but you’re much more likely to achieve success if you start with good stock. Which brings me to the point of this article. I would like to recommend that you try raising plants from seed obtained from a New Zealand specialist nursery called Dowdeswell’s Delphiniums. Just to be clear, I am not in the employ of said nursery, nor have they solicited an endorsement or offered me kickbacks. (I wish someone would offer me kickbacks.) It’s simply that their seed produces healthy, lusty, gorgeous plants. They show up the Pacific Giant and Round Table strains for the trash they are. (The Pacific Giants haven’t been worth much since the plants stopped being hand-pollinated, after the death of their originator, Frank Reinelt, in 1979.) And though it pains me to say it, the Dowdeswell plants also outshine the Karl Foerster delphiniums that I brought back from Germany and that thrived for many years in my Boston garden. Alas, my German Kinderlein seem not to care for the local soil and climate—in Portland they are but weak, pale versions of their former selves.
To get going, you simply order seed from the Dowdeswell website (www.delphinium.co.nz). There’s quite an impressive choice. Among the fourteen “named lines” you’ll find ‘Royal Aspirations’ (a mixture of vivid blues); ‘Sunny Skies’ (sky blue with a white “bee”); and ‘Black Eyed Angels’ (white with a dark bee). The line of “specialist colours” offers a deep blue strain with a white bee (my favorite) and blues with a black, brown, or yellow bee. There are also four mixtures that feature especially tall or short plants, or mixed colors with large bees or double flowers. I haven’t mentioned the many strains with purple or pink flowers, because, really, why would you bother? (Oh, I suppose the purples are all right.) Each packet costs NZD$18.50, which translates to about $9.60 U.S. Yes, that’s a lot, but you’d probably pay at least that much for a single plant at a nursery, and I’ve found the germination rate of Dowdeswell seed to be high—often 80% or more.
Once they’ve sprouted, the seedlings are remarkably vigorous. If you start the seeds indoors under lights in January or February and plant the seedlings out in April or May, you’ll probably get flowers that very first summer. Mature plants invariably give you two periods of bloom per year: one in late June/early July and another in September. Give them full sun; rich, well-drained soil; generous applications of the organic fertilizer of your choice (“Feed me, Seymour!”); a healthy dose of ground limestone; and sufficient water during the dry months of summer. You’ll have to stake them; beauty is never without its price. And be sure to take measures against slugs with some reasonably benign product like Sluggo. When most of the florets have withered, cut the entire plant to the ground—you don’t want it to put its energy into seed formation. New foliage will appear almost immediately, so you don’t need to worry about filling a gap in the border.
If, when your delphiniums bloom, you do not stand before them mute with adoration and barely suppressed ecstasy, well, then, I fear for your soul. In the words of the poet Wallace Stevens, you are at “The heraldic center of the world / Of blue . . . / The amorist Adjective aflame. . . .”
Nevertheless, it is fair to ask how you can best incorporate this almost overwhelming beauty into your garden. Tall delphiniums are not what I would call versatile plants. They are highly bred border denizens, meant for certain settings and carrying with them specific connotations. They are marvelous in a traditional, densely planted perennial border. They sing against a background of white birches and dark pines. And as the Belgian landscaper Jacques Wirtz has shown, they lend themselves beautifully to highly formal situations, such as filling up geometric, box-edged beds. In his book On the Wild Side, Keith Wiley suggests underplanting them with a carpet of Tanacetum niveum, so that their soaring blue spikes will rise out of a sea of small white daisies. Brilliant.
Where tall delphiniums will not work is in your meadow garden, among the unruly tufts of sedges and grasses, or in some similarly naturalistic setting. In those kinds of gardens they make the surrounding plants look shabby, and they themselves look as though they’re waiting to hook up with some randy sailors on shore leave.
Which brings me to a sad irony. My back garden, where I grew my delphiniums, is undergoing a radical redesign in which they would look woefully out of place. I might be able to accommodate some of the shorter-growing Asian species, like Delphinium grandiflorum or D. tatsienense, but the Dowdeswells will have to go. You can’t have everything.
So, for the time being, I cannot grow tall hybrid delphiniums. But I hope you will.
A version of this article first appeared in The Bulletin of the Hardy Plant Society of Oregon, vol. 25, no. 1 (spring 2009).