By Lynn Byczynski
Cut flowers are one of the most profitable crops to grow in a hoophouse. The minimal protection of an unheated hoophouse brings a wide range of benefits: excellent flower quality, longer stems, fewer pests, and a much longer season of harvest.
The best varieties to grow in a hoophouse depends somewhat on your climate. You should use the valuable space inside a hoophouse for crops that won't do well outside or that you can't grow outside at all because of wind or late frosts.
The key to successful hoophouse production of cut flowers is to experiment. Your climate and markets will determine the best varieties for your situation. Here are some basic guidelines to consider in choosing the best crops for your hoophouse.
In the South and in mild coastal areas, some cool-loving flowers will grow all winter without adding heat to the hoophouse. In colder areas, the hoophouse provides just enough protection to grow these varieties very early in spring or later in fall than usual. Daylength may limit blooming for some varieties, but even flowers that won't bloom in the short days of winter can put on significant growth and be ready to send up stems as soon as the days get longer. Day-neutral flowers will bloom as long as the temperature is acceptable. Some of the top crops for hoophouse production in cool weather:
- Anemones, Dutch iris, freesias, and ranunculus are high-value cut flowers, grown from bulbs or corms.
- Ammi majus, bupleurum, campanula, delphinium, dianthus, digitalis, larkspur, lupine, snapdragon, stock, and sweet peas are seed-grown flowers that love cool weather.
- Single-stem sunflowers are a great crop for early spring, late fall, and even winter in mild areas. Grow a day-neutral variety such as the 'Sunbright' series, plant them closely, and replant every two weeks for a long harvest season.
It may get too hot for human comfort inside a hoophouse in summer, but some flower varieties can take the heat and even thrive on it. Be sure to provide as much ventilation as possible, such as by removing end walls, so that the hoophouse cools off at night. And pay attention to the plants' water needs they may require more frequent irrigation inside the hoophouse than in the field. Don't plant varieties that are prone to foliar diseases because the still air inside the hoophouse may worsen the problem. Zinnias, for example, are more prone to problems inside than outside.
In extremely hot summers, the best flowers for the hoophouse are celosia, lisianthus, and ornamental peppers. In cooler areas, most summer flowers can be grown in a hoophouse. Delphinium, for example, will bloom repeatedly throughout the summer in a hoophouse. Lilies can be planted sequentially for a long season of harvest. Annual dianthus such as 'Amazon Neon' can be succession planted for several flushes of flowers.
For more ideas about hoophouse production of cut flowers, see my books: The Flower Farmer: An Organic Grower's Guide to Raising and Selling Cut Flowers and The Hoophouse Handbook.
Lynn Byczynski is the editor of Growing for Market and the publisher of The Hoophouse Handbook.