Why is February the chosen month for Valentine’s Day? It’s certainly not the ideal time for those cultivating cut flowers, as nurturing blooms during winter’s peak is challenging.
Many of the winter and early spring blossoms found in markets are imported. Yet, domestic flower producers in the U.S. have developed innovative techniques to ensure a steady supply of cut flowers throughout the year.
As winter’s chill sets in, flower cultivators across the globe begin the process of winterizing their fields, marking a period of reduced activity. For many, this downtime is a welcome break, a chance to enjoy the tranquility of the colder months.
However, for some, this season prompts a critical question: “How can we sustain our crop production during these colder months?”
Cut-flower farming has rapidly evolved into a lucrative sector for small-scale farmers, transforming what once were mere hobbies into substantial and swiftly expanding enterprises.
Driven by this success, numerous farmers are keen to maximize their profits, extending their productive season well into winter.
This is where the concept of ‘season extension’ becomes pivotal, especially for small-scale cut-flower farms. It’s a strategy that’s applicable and beneficial for farms of various sizes.
In light of this, we’ve compiled a selection of strategies to prolong your harvesting period and relish the beauty of cut flowers for a longer duration.
Learn How To Unleash the Beauty: A Beginner’s Guide to Cut Flower Gardening
Cut Flower Production: Beyond the Heated Greenhouse
In cultivating cut flowers throughout the year, utilizing a fully heated greenhouse is the most effective and popular method. However, many smaller-scale flower producers shy away from this investment, opting for alternative solutions.
Bob Ambrose from Ridgeview Acres Farm in Stahlstown, Pennsylvania, refers to these alternatives as “protected growing structures.” These include hoophouses, high tunnels, and cold frames, which may lack heating or offer limited supplemental heat.
They typically don’t have a cooling system, with roll-up sides being the exception, and their height varies based on the specific crop needs.
These structures are pivotal in extending the growing season and safeguarding crops. This extension can range from inducing early bulb growth to cultivating cut flowers in the colder months, and even safeguarding late-season crops from early frost.
The market often values early and late-season flowers more, making this a profitable venture.
Hoophouses, which may be unheated or lightly heated, allow growers to begin planting and harvesting a month earlier in spring and extend the season by a month in autumn for those final harvests.
Crop protection in this context goes beyond guarding against late spring frosts. It encompasses shielding from strong winds, rain, and hail, significantly benefiting cut flower cultivation.
In these sheltered environments, flower stems grow taller, aided by protection and reduced light transmission. Implementing shade cloth is more feasible in greenhouses or hoophouses than in open fields, promoting further stem growth.
Additionally, setting up support structures is often more straightforward in these enclosed spaces.
The overall quality of the flowers also sees improvement due to better control over pests, diseases, and damage from wind, enhancing the resilience and beauty of the cut flowers.
The Art of Balancing Temperature for Optimal Flower Production
Diversifying their approach to hoophouse farming, many cultivators are now incorporating a bit of heating into their structures. This minor adjustment can significantly impact plant growth.
Renowned experts like John Dole from North Carolina State University and Vicki Stamback of Bear Creek Farms in Stillwater, Oklahoma, discovered this through their research in Oklahoma.
They specifically focused on maintaining night temperatures between 35 and 55 degrees Fahrenheit for spring blooms like lupines and stock.
Their findings were enlightening: a steady 40 degrees Fahrenheit struck a perfect balance, minimizing fuel consumption while ensuring high-quality flower production without notably hindering growth.
Eliot Coleman from Four Season Farm in Harborside, Maine, has successfully adapted this approach for vegetable cultivation in Zone 5. He found that combining unheated low tunnels with floating row covers effectively grants two additional protection zones.
This method also proved fruitful for cut snapdragons, as demonstrated by researchers at the University of Arkansas.
They strategically used floating row covers on nights when temperatures were expected to dip below 32 degrees Fahrenheit – a scenario that occurred only eight times throughout their Zone 6 winter.
Think of it as tucking your plants into a warm bed. This is essentially the role of the ‘frost cloth’ or row cover. These covers are cost-effective and one of the simplest ways to extend your growing season. Made from lightweight fabric, they can be gently laid over crops.
While commonly used to ward off pests, these row covers are excellent at retaining heat, protecting plants from early frost damage.
Depending on their type and thickness, they can raise the ambient temperature around the plants by 2 to 8 degrees Fahrenheit, a crucial difference as winter approaches.
Furthermore, row covers can cover biennial and overwintering cut-flower crops, stimulating earlier blooms in spring. This simple addition could potentially extend your farming season, generating several more weeks of revenue.
In summary, these innovative methods of using minimal heating and protective covers in hoophouses present a new frontier in efficient and productive farming practices.
Learn How to Prepare Your Farm for Winter: Essential Tips for Farmers
Seasonal Strategies in Flower Farming
The Festive Season of Christmas
During the bustling holiday shopping season, cut flowers emerge as a popular gift choice among shoppers. While cut poinsettias are relatively new to the market, they are gradually gaining recognition.
Cultivars like ‘Renaissance Red’ and ‘Renaissance White’, developed specifically for cut flower production by Ecke Ranch, are noteworthy examples.
At institutions such as North Carolina State University and the University of New Hampshire, these plants are cultivated in 8-inch azalea pots, ready for the market by early December. In 20 weeks, they grow stems ranging from 20 to 24 inches.
However, a heated greenhouse is essential for their growth since they are sensitive to temperatures below 50 degrees Fahrenheit. An alternative growing method is using ground beds.
These cut poinsettias boast an impressive vase life of three weeks and are often seen as a novelty in floral arrangements. Typically, they are arranged with white and green foliage to create festive holiday bouquets.
Celebrating Valentine’s Day
Bleeding hearts are a symbolic flower for Valentine’s Day.
Research by Ingrid Mallberg and Laurie Hodges at the University of Nebraska has shown that pre-chilled bleeding heart crowns, planted in January and subjected to night temperatures of 35 degrees Fahrenheit and day temperatures of 65 degrees Fahrenheit, thrive in 1-gallon containers using standard potting mix.
This results in two to three high-quality stems in their first year under 63-percent shade. In contrast, white bleeding hearts produce about seven stems in 5-gallon plants without shade, with a harvesting period lasting 5-6 weeks.
The vase life is remarkable, with red flowers lasting 12 days and white up to 17 days, making them perfect for Mother’s Day and June weddings.
Despite the existence of pink cut poinsettias, their popularity for Valentine’s Day is still developing. However, tulips, particularly those grown hydroponically, are a major February crop.
Tom Wikstrom from Happy Trowels Farm in Ogden, Utah, cultivates hydroponic tulips from pre-chilled bulbs.
These bulbs are placed in plastic trays for nutrient water circulation, initially grown at 40 degrees Fahrenheit for 2-4 weeks before transferring to a warmer greenhouse.
The harvesting process is straightforward and produces cleaner, earlier blooms than soil-grown varieties.
Spring and Summer Annuals
Joe Caputi of Charlotte’s Garden in Louisa, Virginia, gains an early start on spring flowers with his two hoophouses. These structures, unheated and covered with a single layer of poly, allow direct ground planting.
He cultivates various flowers, including tulips, ranunculus, anemone, sweet peas, poppies, larkspur, bupleurum, and sweet William, providing him with a diverse early spring offering for the market.
Moreover, Caputi ingeniously double-crops his hoophouses in the summer, planting annuals such as zinnias, ageratum, sunflowers, and celosia.
This technique enables him to plant these varieties 2-3 weeks earlier than if they were planted in the field, enhancing his seasonal yield.
Comparing Greenhouses with Cold Frames and Tunnels
Exploring the Potential of Caterpillar Tunnels and High Tunnel Cold Frames
Using cold frames or caterpillar tunnels is a game-changer for extending the growing season. They’re particularly effective for prolonging the harvest of flowers like dahlias and heirloom mums, among other varieties.
These structures function similarly to row covers by protecting plants from frost and lengthening the growing period.
However, they tend to maintain a warmer environment inside, which can vary based on the tunnel’s size and quality. While more cost-effective than a full greenhouse setup, they are pricier than floating row covers.
These tunnels don’t feature the heating or climate control found in traditional greenhouses. External weather conditions influence their internal temperature.
Nonetheless, they can significantly expand the sales window in autumn and early spring. Many flower growers and gardeners utilize these year-round, gaining an advantageous early start in spring.
Read more about Extending Your Growing Season: Harnessing the Power of Cold Frames in Your Garden
The Distinct Advantages of Greenhouses
In this discussion, we reserve the term ‘greenhouse’ for structures that can actively heat the air inside. Many greenhouses not only provide heating but also incorporate fans for air circulation.
The heating sources vary, including wood, water, or electricity. Greenhouses offer the best solution for those aiming to cultivate cut flowers throughout the year.
Beyond the extended growing capability, greenhouses offer an invaluable space for starting cut flower seeds. The beginning of the growing season hinges on the health of these seedlings.
Without them, maintaining a successful season can be challenging. Small farms often lack this space, leading them to purchase many plant starts or ‘plugs’ in early spring.
By starting your plants in a greenhouse, you cut operational costs and ensure a robust start to your season.
Regardless of the chosen method for extending the growing season, each can significantly boost the prospects of a small cut-flower farm.
However, starting small and scaling up is a perfectly viable approach. Many successful flower farmers have thrived for years without these structures, proving their optional, yet beneficial nature in the industry.
The Power of Plastic Bulb Crates in Lily Cultivation
Lilies, known for their captivating appeal and profitability, are a top choice for cut flower growers. They thrive exceptionally well in plastic bulb crates.
Available in two sizes, the larger crates (25½ x 15½ x 10 inches) are typically preferred for lilies, while the smaller ones (14½ x 22 x 8 inches) are ideal for tulips and smaller bulbs.
Growing lilies in bulb crates offers several advantages over traditional field cultivation. It eliminates concerns like weed control and simplifies the management of water, nutrients, temperature, and drainage.
The mobility of crates, whether placed on benches or pallets, aids in monitoring staggered plantings effectively.
Dave Dowling from Farmhouse Flowers and Plants in Brookeville, Maryland, exclusively uses crates for his lily production, planting 15 to 18 bulbs per crate, an approach necessitated by his limited space.
Research at the University of Maryland by Stanton Gill highlights the effectiveness of the crate system. By starting as early as mid-February in heated greenhouses, growers can time their harvests for high-demand periods like Thanksgiving and Christmas.
In Zone 8, Crofton Sloan and Susan Harkness from Mississippi State University cultivated various lilies in crates within unheated hoophouses, planting in late March and harvesting by early June.
The crate system is suitable for a range of bulbs. For example, planting Ornithogalum, or Arabian star flower, in October sets up for Easter sales. It flourishes in cool greenhouses, producing superior quality flowers and long stems under controlled temperature conditions.
Harry Wilfong of Wilfong Greenhouses in Newton, North Carolina, grows lilies, snapdragons, and callas in containers.
He plants four lilies or snapdragons per 6-inch standard pot and uses support netting as needed. His callas thrive in 2- to 3-gallon pots on metal benches, allowing for quick removal of any plant affected by Erwinia.
The Ground Reality of Crate vs. Ground Cultivation
While crates are space-efficient and compatible with many bulbs, some growers observe a drop in quality compared to ground-grown plants. This issue is also seen in hydroponic tulip cultivation.
Vicki Stamback, preferring ground cultivation for her greenhouse crops, notes improved quality with larger flowers, taller stems, and fewer insect problems.
Her winter crops include traditional cool-weather varieties and uniquely, sunflowers grown in flats, yielding perfect bouquet-sized blooms.
Greenhouse cultivation also opens opportunities for growing plants like trachelium and delphinium, which are unsuitable for field cultivation due to environmental challenges.
Many growers resonate with Stamback’s preference for more greenhouses, as they offer a competitive edge against imported flowers. As Amy Stewart points out in “Flower Confidential,” most cut flowers sold in the U.S. are imported.
However, with strategies like extended season cultivation, U.S. growers are actively competing, continuing to make their mark in the cut flower industry.
Read more about Starting a Flower Farming Business: Lessons Learned from My First Season