A New Twist On Freesia

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A New Twist On Freesia

I am always surprised to hear growers say they think freesias are not an interesting product. Many say freesias are not in vogue, that they’re old-fashioned or a crop without profit. I say today’s freesia cultivars make excellent cut flowers, and with the right treatment they can be excellent potted plants, too.

Longwood Gardens visitors adore freesias. Over the years, they came to expect the eloquent presence and the pleasing fragrance of freesias in the winter and spring display. Not at all shy, visitors will tell me if the flowers are not displayed on time–or not scented enough.

In my mind, it is easy to see why people enjoy freesias. They are a timeless floriculture standard: the raceme-like flower spike consists of a number of flowers that bloom in sequence for an extended period of time. The blooms may be single or double, and they come in colors ranging from whites and yellows to reds, pinks and blues. And traditionally, freesias have been very fragrant. Certainly, for our visitors, the fragrance of freesias has become a trademark of Longwood’s late winter and early spring displays–right along with hyacinth, daffodils, hybrid lilies and our citrus trees.

All current cultivars have one thing in common that should be of interest to cut flower growers: they are tall and well suited for cut flower production. Recent breeding efforts have favored long strong stems with lots of flowers, although the foliage of some cultivars has often been rather disappointing. Also, growth habit and complicated culture requirements make freesias a poor pick for pot production–at least this seems to be the widely accepted opinion. It is my intention to illustrate that this assumption may be incorrect and, perhaps, ready to be put to a test.

Production

Most plants grown for Longwood’s display are produced in containers for easy transportation and transplanting into flowerbeds of the conservatories. This includes freesias. Expected crop proportions are specified by the display designer who likes plants that are tall and showy.

Due to their growing habit, freesias require staking and elaborate tying–a very time-consuming task. With all this TLC, I produce super-sized pot crops that make astonishing mass displays in the conservatory–but certainly would be impossible to sell to the consumer market. Perhaps due to my ever-changing production schedule and the need for extra plants, I need to either hold plants in the cooler–until bench space becomes available–or delay potting.

Following my regular schedule, corms are planted in October and November. These pots will come to flower in February and March, producing these oversized container plants mentioned. In addition to the regular production, this year’s schedule asked for an additional crop for April display. Due to this complicated schedule and limited growing space, the potted freesia corms were held in coolers at minimum temperatures. The temperatures of the growing compartment were also maintained low because the other crops in this compartment required very low temperatures.

In short, the April crop of freesia was being treated the wrong way. I was rather worried about all these compromises. I was not even sure I would have a crop, or if the crop would flower on time.

These plants came into flower this spring, but the crop was completely off specifications. While I normally grow plants about 36 to 42 inches tall, this year’s crop would be an absolute knockout pot crop if I was growing for the consumer market. The plants are now budded up and have an average height of 8 to 10 inches. The stems are sturdy and self supporting so they don’t need staking. The foliage is dark green, attractive and compact. The flower buds are normal size, so I am a bit anxious about how the stem will hold up once the flowers start opening–considering that ‘Yvonne’ is a double-flowered cultivar. Although I am very excited, our display designer is less enthusiastic about these midget freesias.

An Alternative Approach

When working with freesias it is advisable to find a supplier that works for you. Over the last five years, Leo Berbee Bulb Company in Marysville, Ohio has been my supplier of choice for freesias. For you, it will be important to determine if you like to work with prepared (pre-cooled) material or with standard corms. Standard corms require a pre-cooling treatment. Furthermore, the supplier should help you develop your planting schedule based on your local conditions.

Because Berbee knows how my production works, it has been extremely helpful finetuning my production schedule. Another important factor when working with freesias is to order according to the planting schedule. If corms are stored too long or at a wrong temperature, they will “pupate” and develop new side corms rather than grow a plant with flowers.

Freesias require a well-drained media. Most cultural mistakes are made by choosing the wrong media or by poor water management. If pots stay too wet, freesias will suffer root and bulb rot. However, actively growing plants should never dry out completely. The delicate root system simply desiccates and plants become victim to opportunistic infestations.

I use a specific Freesia mix consisting of the following components: 40 percent peat moss, 25 percent sand, 20 percent pine bark compost and 15 percent vermiculite. The pH is adjusted with lime to a range of 6.0 to 6.5, and I add RootShield at a rate of 1.5 pounds per cubic yard. Corms are planted into 6-inch fiber pots about one inch under the soil level.

While I plant 12 corms to a pot, for commercial purposes, 10 corms per 6-inch pot should be sufficient. The potted corms are normally brought to the bench right away. However, freesias can be started in a cooler with a temperature range of 48-55°F. I sometimes leave the pots in a cooler for up to three weeks, or until first shoots are visible. At this point, the pots need to go to the bench, otherwise shoots will stretch too much.
Suggested light levels are around 3,000 footcandles. Because I grow freesias during the low light winter months, I use supplemental light to ensure proper plant development. The growing lights provide supplemental light and extend the day to 14 hours.

Freesias need adequate nutrition and should be fertilized every 10 days. I have had good results with Peter’s Excel 15-5-15 CAL-MAG Special from Scotts-Sierra Horticultural Products Company. It’s a water-soluble complete fertilizer applied at a concentration of 150 to 200 ppm.

Temperature & Bench Time

Flower bud initiations for freesia will occur at temperatures below 48°F. I keep temperatures at 41°F because we are also growing other cool crops in the same greenhouse compartment. At this low temperature, my freesias usually require about 95 to 110 days, although the time requirement varies among different cultivars. This is about 20 to 25 days more than when freesias are grown at the regularly suggested temperature range of 50 to 60°F. The longer bench time is offset by improved crop quality. The growth habit is compact and sturdy and plant height is significantly reduced.

Market & Post Harvest

Freesias are ready for market when flower buds show slight pigmentation. At this stage, they should be shipped or placed in a cooler. Although freesias can be stored at 33°F for a few days, storage should be kept to a minimum because plants will deteriorate. Make sure there are no sources of ethylene in the cooler–do not store fruit and freesias in the same cooler. Ethylene will lead to a rapid decline of the flowers. Temperature management during storage and transportation, as well as at the sales location, is a must. At a temperature range of 62 to 68°F, freesias have a very long shelf life–up to four weeks–but temperature spikes over 70°F will reduce longevity of the crop to just a few days.

More Tests Are Needed

Because Longwood’s freesia display is popular with our visitors, one surely can speculate on a potential market for potted freesias. By late winter, people are longing for color and the scent of spring. Perhaps in the future, Dutch breeders will provide us with new dwarf cultivars suitable for pot production without the need for complicated growing environment modification and/or application of PGRs.

Until that time, low-growing temperature production perhaps could be the answer for growing potted freesias. For areas with inconsistent winter temperatures, a combination of PGRs and low-growing temperatures could provide the tools needed for producing consistently compact pot freesias. Growing crops at low temperature increased production time by about two to three weeks. However, the compactness of the pot crop was achieved without the use of PGRs. In addition, the minimum temperature input should provide for an improved carbon footprint–a more sustainable approach to crop production.

Juergen Steininger is a grower at Longwood Gardens in Kennett Square, Pa. He can be reached at juergensteininger@yahoo.com.

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