SPECIALTY CUT FLOWER CORNER: For the beginning grower

Living the high life
High value flowers have high standards and absolutely thrive in high tunnels. So, Mel and George are adding another gothic arch to their property and populating it entirely with the best-selling blooms.

By Melanie DeVault

A little bit about Melanie

Melanie and husband George own a 19.2-acre certified organic farm in Emmaus, PA, where they, with son Don and daughter Ruth, have operated a modified CSA and members-only home market stand, sold at Farmers’ Markets, to health food stores and restaurants. Melanie specializes in specialty cut flowers. A former newspaper reporter, she also is a freelance garden writer. She is a member of the Association of Specialty Cut Flower Growers.


I’ll be happy to anwer them!

E-mail me at devault@fast.net and include your name and general location.

Posted January 7, 2005: Experience is the best teacher, they say -- and our experience has screamed “build another high tunnel just for flowers!” Flowers, especially the higher value varieties like lisianthus, campanula and dahlia, have done extremely well for us in limited beds under cover. High tunnels, with little or no supplemental heat, can give you a much wider window for earlier and later sales with everything from stunning celosia and dianthus to out-of-season sunflowers, of which, thus far, our customers never seem to tire. (Alleluia!)

“But I’m a beginner!” you say. If you’re a serious beginner, and have had some practice with growing outdoors, a high tunnel or even a modest hoophouse will pay for itself in no time (and, hey, then pay YOU). Perhaps the biggest benefits we local growers have over cheap imported flowers are fragrance and freshness. In a word, real QUALITY.

You’ll be surprised how much more you can make by growing flowers under cover that tend to bruise or flatten easily in the wind and rain, like lisianthus. Lissies also like the heat, and we had four flushes in our beds under cover from mid- summer to late fall. Of course, we worried customers wouldn’t want pastel flowers into October. But they just can’t get enough of lisianthus once you get them hooked no matter the shade! Sweet peas, dianthus and other fragrant flowers can also be real moneymakers in winter or early spring. Florists loved our early dianthus from the high tunnel, which we planted in fall and overwintered.

So, we’re listening to experience and husband George has been out sawing and fitting away under the watchful eyes of our guinea hens, through cold and rain, mud and snow flurries, because once the plastic is on, work under cover isn’t nearly so much like work. Working pretty much alone, George had the frame up in a few part-time days. The finish work on the frame and doors has taken longer than usual because he’s fussing, but we’ll have the plastic on this week with the help of a few friends.

The style we’re putting up is a 21- by 96-foot gothic arch with 5-foot roll-up sides. George took down our first, narrow (14- by 96-foot) hoophouse to use the prime real estate for the new structure. The soil is good and the ground ready for growing. But the best thing about this site is it’s about 50 feet from the back door, already has electric, has an easily accessible water supply, and is close to our seeding greenhouse. Cost of the new greenhouse frame (2,070 pounds) from Ledgewood Farm (Ed Person, e-mail is ed@ledgewoodfarm.com) was $2,375; roll-up sides an extra $364, so it cost us $2,739 plus freight, $392.40. Plastic, 6 mil infared, which holds heat in at night and reduces condensation, weighed in at 108 pounds (Klerk’s K50 IARC 36-foot by 100-foot) and cost $277.99 from a nearby greenhouse supply company. Baseboard and hip-board (roll-up side) lumber was another couple hundred dollars. George used leftover polycarbonate panels to make double doors. Barring any major temper tantrums from Mother Nature, we should easily make back the cost in one season. (For more general greenhouse how-to, please see our greenhouse columns on this website).

My flower partern, Linda Essert-Kuchar, and I will be working over winter readying the beds for early spring planting, incorporating compost in the top 2 inches of soil and designing the beds to get maximum benefit. Experience (mistakes) over the past two years has taught us space in a high tunnel is precious.

The crops

Major crops for us next year will be sweet peas, stock, snapdragons, lisianthus, campanula, and sunflowers. We have fall-planted dianthus in another high tunnel, but we will do another planting in the new greenhouse. And, we’ll experiment with other flowers.

At an October workshop on high tunnel production for commercial cut flower growers at Dave Dowling’s Farmhouse Flowers & Plants in Brookeville, MD, Dave offered specific tips on a number of flowers. The workshop was sponsored by the University of Maryland Cooperative Extension, the Maryland Greenhouse Growers Association and the Association of Specialty Cut Flower Growers (ASCFG).

Dowling has two 30- by 80-foot double poly high tunnels constructed with skids and a track, which he can move with a tractor. This type of system, which Eliot Coleman has successfully used for vegetables/greens for years in coastal Maine, can protect one planting area in spring and another in fall, Dave says. For tulips, this system is perfect, he adds. Dave planted 2,000 tulips in raised beds late October, 3 inches on center in the uncovered “track” area. To stagger bloom time, half were planted 6 inches deep and half 8 inches deep. He watered them once. In spring, the high tunnel was moved back over the tulips March 1. They were up in a week and bloomed in three to four weeks. “They were 18 to 20 inches tall (pulled). We got $1 a stem at market, 80 cents to florists.” Because early and late varieties were planted, Dave was able to harvest for five weeks, including the Easter holiday!

He planted sunflowers, stock and delphinium in high tunnels on March 1. Lisianthus was planted in April. This past spring, he also planted lilac and viburnum to see if they would produce earlier than field plants.

Other crops Dave has had success with in high tunnels include:

Sweet William -- Produced a week before field-grown plants, and while stem length was the same, flower quality was better, probably, he says because they didn’t get the excessive rain that the field flowers did.

Bachelor button -- Taller and better quality flower than those grown in the field. They bloomed 10 days earlier, too.

Yarrow -- Coronation Gold and Moonshine, 2-year-old plants and plugs planted in August. Both varieties bloomed three weeks earlier than field plants. Stem length was 36 inches, with 10-12 stems per plant.

Campanula -- Bloomed same time as field grown, but on taller stems (30 inches compared to 20 in field -- very important if you sell to florists or wholesale).

Sunflower -- Sunbright Supreme transplants planted third week of March and again second week of April (plugs started in greenhouse and ready to transplant in 10 days). They bloomed in 8-10 weeks. (This was the only crop that had a problem with insects, so watch them carefully. We had a problem with aphids in fall on this crop. Think ladybugs!).

Lisianthus -- Planted mid-April and harvested beganing mid-June. “I feel the only place to grow Lisianthus is in some kind of high tunnel or greenhouse,” Dave says. Quality is exceptional. (We whole-heartedly agree. Our time frame was the same in Pennsylvania.)

Salvia Leucantha (or Mexican bush sage) -- A short-day salvia that starts blooming in late September and is a good candidate for high tunnels because an early frost can kill it just as production is at its peak. “Last fall we had Salvia Leucantha up until Thanksgiving,” Dave says.

Eucalyptus -- Since this isn’t harvested until late summer when leaves start to turn leathery, it benefits from the extra warmth of a high tunnel in fall. It will continue to branch. Pinch the top.

Celosia -- Protection from rain helps and they like it hot. Even a light frost will kill them, so added protection of row cover can extend production.

Dahlia and cosmos are other good fall crops if protected from frost. (The dahlias we did under cover in Pennsylvania succumbed to an unexpected 19-degree night. Row cover and low heat would have saved them, we believe. We were caught unaware.)

As Lynn Byczynski explains in her Hoophouse Handbook, “the most successful flower growers are those who can match day length requirements to their temperatures in the hoophouse.” This varies widely by location, so there can be no exact formula. But as she says, any flower that is a short day plant or day length neutral is a good candidate for a minimally heated house. (Byczynski's handbook is available at www.growingformarket.com; phone 800-307-8949. Another website with information on growing in high tunnels is www.hightunnels.org which includes research information. )

Other good candidates for unheated hoophouses that we have not menthioned, Lynn says, include: Anemone coronaria, bupleurum, delphinium, Dutch iris, Larkspur, Lupines and Stock.

High Tunnel Tips

Just a few high tunnel growing tips:

  • Dave uses a loop system on his drip irrigation in the high tunnel instead of cutting each strip. Seems like a good idea which we will try next year! Just loop the drip around at the end of the bed and come back down. Be sure to use enough drip lines per bed to cover all flowers.
  • In spring, you need to worry about the houses getting too hot. Keep them well ventillated. In fall, it’s better to have them too hot than too cold, Dave says.
  • Watch your placement of flower crops in the high tunnel. Dave says he’ll do eucalyptus and blue horizon ageratum on the sides, instead of down the center. (We had placement mistakes, also. If you do sweet peas in the greenhouse, think center, with two horizontal layers of netting placed vertically, one on top of the other. They’ll get very tall. Don’t forget to support flowers with Hortonova netting in the greenhouse because crops like snapdragons will also get very tall!)

Bryan Butler, a University of Maryland Extension educator, Carroll County, offered some tips on low cost-structures and economical ideas at the workshop, including:

  • The gothic design is a durable design. It lived through the 2002 snows with single layer poly, while others fell down. Even a 2 to 3 percent slope helps on a structure.
  • Greenhouse patch tape or even wrapping any rough spots in duct tape before putting on plastic can save you wear -- and tear.
  • Gravel (an in-between size) around the structure can be a good deterrent to rodents.
  • Irrigation line on top of landscape fabric soaks in yet allows you to easily find and repair holes in the line.

“I believe this is the future of agriculture in Maryland, what you’re looking at right here,” Butler said, pointing to Dave’s high tunnels at the workshop. “The quality, what you can produce.” We second that for Pennsylvania. And just about anywhere.