Freesias feature slender stalks of deliciously fragrant, tubular flowers that bloom in clusters in winter or spring. They are normally grown in containers to make it easy to control the soil conditions, and the entire pot can be brought indoors for storage when the plants are dormant. The plants are winter-hardy in U.S. Department of Agriculture plant hardiness zones 9 and 10 where they can be planted outdoors in the garden. Plants are propagated from seeds or corms.
Freesia needs full sun and a well-drained, fertile soil. Once the foliage appears, the corms need plenty of moisture. After the blossoms fade the plant goes dormant and you should withhold moisture until the following season. Use a liquid fertilizer at two-week intervals from the time the buds appear until the last of the blossoms fade. In pots, use a soil-based potting mix with added sand to improve the drainage.
Plant the corms indoors in spring or outdoors in USDA zones 9 and 10 in the fall. Cover them with 1 to 2 inches of soil and space them 4 to 6 inches apart. Unlike bulbs, corms die each year and are replaced by new corms that grow on top of them. If you dig one up, last year's corm will appear as a flattened disc under the new corm. Break off the old corm and remove the small offsets, called cormels, which are attached to the bottom of the corm. You can use the cormels to start new plants.
Plant cormels in a separate pot under 1/2 inch of potting soil. Tend the pot as you would if you had planted full-sized corms, feeding and watering the cormels regularly in the spring and early summer and allowing them to go dry in the summer. Cormels produce foliage but no flowers for the first three or four years. After four years, lift the corms while they are dormant. Dry the corms and store them in a well-ventilated area in a paper bag until planting time.
Freesia can also be propagated by seed. Soak the seeds in warm water for 24 hours before planting them. Sow them outdoors in zones 9 and 10 in the spring when there is no danger of frost. Indoors, keep the air around seeds humid by starting them in trays with a plastic cover or by covering individual pots with a clear plastic bottle with the bottom cut out or enclosing them in a plastic bag. Remove the cover when seedlings emerge. The seeds germinate best at temperatures between 65 and 75 degrees Fahrenheit. Expect seedlings in 25 to 30 days.
- The Gardener's A-Z Guide to Growing Flowers from Seed to Bloom; Eileen Powell
- Plant Propagation A to Z; Geoff Bryant
- The Propagator's Handbook; Peter Thompson
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