Note: Click here to see photos of some of these delphiniums.

I can never grow enough delphiniums. I keep trying, but it seems that I run out of space before I run out of demand. The florist I sell to loves delphiniums, both the elatum hybrids and the looser, airy belladonna hybrids. I planted 1,400 plugs for this season, and though I am getting close to the saturation point, I’m not there yet. Next year: 1,600 plugs.

I have a particular approach to growing delphiniums that makes them a profitable and easy crop for me. I’ll tell you all about it, and also tell you how other flower farmers grow delphiniums in different regions of the country. And I’ll tell you about the pros and cons of the many cultivars now available to cut flower growers.

Hoophouse production
I never had any luck growing delphiniums outside. I attribute this to the excellent wind resource we have in Kansas. (Finally, there’s an upside to our windy weather! It’s still hard on plants, but at least we’re harvesting energy.) Delphiniums are delicate – their stems are hollow and their petals papery thin. They don’t do well in an open field. Inside the unheated hoophouse, though, they grow tall and strong.
I order plugs through Gloeckner every summer to arrive in mid-September. The plugs are usually grown in 200-cell trays, so they are a pretty good size when they arrive. After a few days recuperating in the shade somewhere, we plant them into one of our four high tunnels. We never manage to keep them all together because we have to find space wherever we can pull something else out by that time of year. But that may be a benefit, because the minute differences in growing conditions do seem to space out their flowering times a bit.

We keep them well watered for that first month, and they establish nicely as the weather cools down. Going into winter, we will usually have small, well-rooted plants. We used to cover them with row cover, fearing that winter would be too cold for them. But we found that the opposite was true – winter in the tunnel under row cover was too warm for them, and they started sending up flowering stems as early as February. Those stems made the whole plant more vulnerable to cold spells, and we had no market for the flowers that early anyway. Now we just leave them uncovered. Although the leaves may get a little frosted and die back, the centers of the plants always remain green. We have had some winter loss in particularly cold weather, but the vast majority of the plugs make it through. Delphiniums will bloom without a period of chilling (vernalization), but they will be stronger if they get at least six weeks of 35-40°F.

As soon as the weather starts to warm in March, the delphiniums start growing quickly. They form big plants, a foot in diameter. By April, they are sending up tall, thick stems. We don’t put support net or otherwise stake them because the stems are so strong and straight. We usually start to harvest in late April. This year, when the weather was cold and rainy in spring, our first sale was May 6.

We cut the first big stem clear to the ground. Sometimes these early stems are 4-5 feet tall (depending on variety) and so thick we can fit only 10 or 15 in a 5-gallon bucket. The plants quickly send up new stems, not as big but still robust in the cool weather of April and May. They continue to flower until July (mid-July this year). Heat is the limiting factor for them; as the temperature goes above 80°F regularly, the stems get thinner and the size of the flowers declines. A mid-July elatum type is only about 3 feet tall, and a belladonna type is 30 inches. Not that they become unmarketable; to the contrary, they’re probably easier to use for the small designs that are the bread-and-butter for most florists.

Although I could probably extend the season a bit longer with shade cloth on the hoophouse, I don’t bother because by July I have an overabundance of flowers outside and I’m ready to change my menu and the look of my bouquets. I don’t try to keep the delphinium plants alive for the next year, either, because I’ve found that second-year plants are too big and lanky. We just plant new plugs every fall.

Economics of delphiniums
Prices for plugs range from about 10 cents for the belladonna types and the older series such as Magic Fountains to 35 cents for the newest cultivars such as Aurora. I haven’t grown the tissue-cultured ‘Trick’ delphiniums, which I heard cost $2.30 per plant this year. I don’t think I can make any money from those.

My prices to florists range from $1.25 per stem for the big early flowers to 70 cents a stem for the small summer flowers. My 1,400 plugs this year cost about $250; my sales of delphiniums to date are $1,400. Convenient as those numbers turned out, it doesn’t really amount to $1 per plant because some of the varieties I grew didn’t produce much at all. More on that later.

The really important economic factor with delphiniums, though, is that they make it worthwhile to start delivering early, with other flowers that aren’t so valuable – dianthus and aquilegia, for example. In fact, delphiniums and another early spring crop, snowball viburnum, really boost the average May sales ticket.

Varieties
Subtle but significant distinctions affect variety selection for me. First, the elatum hybrids, which are the tall, columnar types:

• ‘Pacific Giants’ are the oldest series I grow and they are the biggest, up to 5 feet tall. ‘Clear Springs’ and ‘Magic Fountains’ are smaller, but still up to 3.5 feet tall in early spring. All three series are available in blue, lavender, purple and white. All of the ‘Clear Springs’ colors have a white “bee”, the little flower in the center of each floret. In the other two series, some colors have a dark, nearly black bee. I like a dark bee on a dark color like purple, because it intensifies the color. On lighter colors, I think a white bee makes for a cleaner color. But that’s a matter of taste.

The florists can use these giants occasionally for big arrangements,but they also find them useful for smaller work because the individual florets can be removed and wired into boutonnieres, corsages, wreaths for flower girls, and so on. One designer told me he had wired together florets into long garlands of blue to hang around an arbor. And they make great confetti to throw at weddings.

• ‘Aurora’ flowers a week or two earlier than the ‘Pacific Giant’ types, and all the colors flower at the same time, which gives you a mixture of the entire color range. The florets overlap, making a thick column, and the petals are sturdy. I especially like the clear, intense color of ‘Aurora Blue.’ All ‘Aurora’ colors have a white bee.

•Another early hybrid is ‘Guardian’ and I find it very similar in performance and appearance to ‘Aurora.’ But there is one amazing color in this series, ‘Guardian Blue’ that shimmers like an exotic bird. Every floret has double petals, with the bottom layer of petals a clear mid-blue, and the top layer purple. It’s mesmerizing, as you can see from the photos that I have put on my blog at www.theflowerfarmer.com

• ‘Candle’ series is a hybrid bred for winter production under short days. But it works fine in spring and summer, too. I grew the white shades this year, and it was a perfectly nice clear white. It’s still blooming in mid-July.

Now, the belladonna forms, whichhave spurred flowers arranged loosely on the stem. They aren’t as tall or cylindrical as the elatum hybrids. But the colors are intense and they look great in a bouquet.

• ‘Bellamosum’ is a dark blue, very tall and strong-stemmed, and a heavy producer.

• ‘Belladonna’ is a light blue, not as tall or productive as Bellamosum. In fact, this is the variety that produced almost nothing for me. But I can’t think of any other flower that color – so I may give it another chance in the future.

• ‘Oriental Blue’ is said to be a color between Belladonna and Bellamosum but it’s pretty clearly a deep blue to my eye. Maybe a bit more electric than Bellamosum, but otherwise the same.

• ‘Blue Shadow’ is shorter than Bellamosum, about the same color, but said to be more heat resistant.

Other growers
I talked to flower farmers in other parts of the country to find out how they grow delphiniums and which varieties work best for them. As might be expected, growers in cool climates are able to grow them outside in the field. Many growers start their own seeds in January for harvest in early summer.

Here are some comments:
Polly Hutchison in Saunderstown, Rhode Island, grows ‘Aurora’ and ‘Oriental Blue’.
“I have grown Aurora delphinium in high tunnels (last year) and outside this year. I got over 15” more stem length in the tunnel. Almost too big, but they were Aurora white and I didn’t want to take chances with browning. This year I grew Aurora blue and purple outside and had enough length (30+ inches). The section they are in gets some shading however.”

Polly grows her own plants from seed, starting them in early February. She says that her harvest window is just a few weeks, and that they don’t overwinter for her so have to be replanted every year. As for market demand, she says, “ I personally love them but I find market customers lukewarm. If you catch a florist with the right party at the right time, they’ll buy a lot, but otherwise they’re happy with larkspur.”

Matt Gerald of Bar Harbor, Maine, used to grow delphiniums but quit because his florists didn’t use many. “I cut them out of the program because then tend to shatter without silver treatment .The florists around here generally don’t seem to miss them or in fact buy in much since I stopped growing them,” he said. When he grew them, he used ‘Magic Fountains’ started from seed in February and planted some outside and some in the greenhouse in crates.

Karen Hanley of North Creek, New York, grows ‘Magic Fountains’ and a Belladonna mix outside in the field. She has some interesting comments about marketing them:

“The Belladonna has that outrageous blue – I plant the mix that includes blue, sky/light blue, and white.  Frankly, this airy, branching variety is MUCH easier to incorporate in Market bouquets than the Magic Fountains variety.  The dark blue, (if the timing is right), mixed with Rudbeckia ‘Indian Summer’ and orange lilies made knock-out bouquets this past week.  While the lilies almost always steal the scene, it was the blue that helped pop the yellow/gold and orange.

“I tried selling sleeves of delphinium only (mixed colors, mixed varieties…some thin stems, some heavy…7 stems for $8) and couldn’t move them.  Oddly, the same thing happened with magnificent single stems of oriental lilies last year – could sell them in a mixed bouquet, but could barely sell any as single stems.”

In the Northwest, Erin Benzakein of Mount Veron, Washington, has always grown them outdoors but now is convinced they could be a great crop for her if she plants them in the unheated hoophouse.
“I have only really grown the Pacific Giants, Round Table Mix so far. Black Knight is amazing! I love the ones with a black/dark bee. My favorites are the Round Table mix from Jelitto.They are so classy and gorgeous! I’ve also planted a ton of the Belladonnas and the Super Star mix from Jelitto but they have yet to flower. A friend grew one called Chocolate; she got seed from Thompson and Morgan. Holy cow, was that thing cool! A deep smoky brownish. It’s still a young plant and wasn’t babied so I have no idea if it would be a good producing plant but I bet designers would freak out over it, especially since anything chocolate is in right now for weddings.”

The Chocolate delphinium Erin mentions is called ‘Phantom’ in Thompson and Morgan (www.tmseeds.com) or at least it looks like the one called ‘Chocolate’ in Wayside Gardens and White Flower Farm retail catalogs. It’s getting a lot of press this year, and it’s one of those things you either love or hate. The petals are tinged with chocolate brown, pink and purple. In Ogden, Utah, Tom Wickstrom grows ‘Guardian’ in the heated greenhouse, planting plugs as early as December 1 and as late as March 15.

“I don’t have a great market for delphinium.  They get it cheap from California and I cannot sell it so easily at a price I’d like,” Tom says. “Still, my best customer swears by my delphinium and usually buys all I have.  She is really high end and very classy.  She does the most expensive weddings and events in our area.”

If you have the market…
These other growers point out potential marketing problems for delphiniums. But if you think you might have a market for them, as I do, I highly recommend you plant a lot, sell all you can, then forget about them. Think of them as an annual that brings in a lot of cash early. Seen in that light, delphiniums are a wonderful addition to your cut flower business.