Helleborus orientalis has not experienced the same increase in popularity as some other shade-loving perennials. A member of the Ranunculaceae (buttercup) family, the common species helleborus was considered rather mundane-looking with its rounded, pendulous, chartreuse flowers. It does have some worthwhile characteristics, including being winter- or very early-spring flowering, nice foliage all season and minimal maintenance. It grows in USDA Hardiness Zones 4-8.
It has taken some creative breeding to show what this plant can really do. A wide range of flower colors -- pinks, reds, whites, white with red spots and purples -- has been developed. Popular seed strains include Ballard Strain, Winter Queen Strain and 'Winter Joy Bouquet.' Jelitto Perennial Seeds' Schmiemann Lady Series Strain produces more than 80-percent single colors. 'Mrs. Betty Ranicar,' which was bred in
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Freshly harvested helleborus seed should be sown in July and August. Sow the seed in open flats containing a well-drained growing medium with a pH of 5.8-6.8. Lightly cover the seeds with medium.
For the next six to 12 weeks the seed must experience a temperature range of 60F-85F. During this initial warm period, cessation of natural hormonal germination inhibitors begins. Keep the medium moist. There is no need for light or fertilizer during this period.
The second seed treatment phase requires temperatures of 25F-40F for 10-12 weeks. These cooler temperatures can usually be provided by naturally occurring autumn and early-winter temperatures. Be careful not to expose seed to extremely low temperatures. In the weeks preceding germination, cover the seed with a thin layer of vermiculite to reduce development of liverworts.
Germination should begin at 40F and will continue as temperatures gradually rise to 50F. Natural light is adequate. Don't raise temperatures too quickly. If the seed is not exposed to adequate temperatures, a second warm and cold period might be necessary.
Transplanting should occur while seedlings are still in the cotyledon stage. Helleborus can withstand early transplanting into 72-plug cells or larger. Gradually prick out the seedlings as they emerge in the open flat.
If transplanting is delayed, roots can elongate very quickly and seedlings can become more challenging to transplant. Use a well-drained medium containing trace elements. Begin fertilization three to four weeks after transplanting with a constant feed of 100 parts per million nitrogen, 10 ppm phosphorous and 100 ppm potassium.
By mid-April, place plug trays under 50-percent shade. Seedlings should be ready to transplant into 4 1/2-inch pots by late spring or early summer. A slow-release fertilizer (i.e., 13-13-13 or 14-14-14) can be topdressed at a rate of 1/2 teaspoon per pot. Maximum light intensity for growing on plants is 5,000-6,000 footcandles.
From plug transplant to salable plant takes eight to 10 weeks. Flowers are produced during the second year after germination.
Grow plants at 50F-65F during the day and 45°F-52°F at night. Summer temperatures for established plants can run higher even under 47- to 63-percent shade. Higher temperatures aren't a problem with appropriate irrigation.
Helleborus has no major disease or insect problems. Occasionally, Rhizoctonia losses may occur as temperatures rise. Control fungus gnats during early plug stages. Look for aphids on emerging leaves.
Specifics
Name: Helleborus orientalis.
Crop timing: From sowing to finish for a 4 1/2-inch pot takes eight to nine months. From transplanting 72-cell plugs into 4 1/2-inch pots, finish time is eight to 10 weeks.
Grower benefits: Cool-weather, low-light crop. No major insect or disease problems.
Selling points: This shade plant flowers from winter to early spring. Available in several single flower colors and a double. Nice foliage all season. Minimal maintenance.
For more: Jelitto Perennial Seeds, 125 Chenoweth Lane, Suite 301, Louisville, KY 40207; (502) 895-0807; fax (502) 895-3934; abush@jelitto.com; www.jelitto.com.