The “toad” in toad lilies (Tricyrtis spp.) refers to the spots common both to the amphibian and the flowers. Those waxy blooms, varying from 3/4 to 2 inches in length, usually appear from late summer through autumn. They boast elaborately designed columns of stamens and styles at their centers, in addition to spattered colors, and their hardiness ranges from U.S. Department of Agriculture plant hardiness zones 4 through 9. Despite their exotic look, toad lilies aren't difficult to grow.
Select Toad Lilies
Among the types rated the most free-flowering by the Chicago Botanic Garden are:
- Formosan toad lily (Tricyrtis formosana, USDA zones 6 through 9), which grows to 40 inches with purple-spotted white flowers up to 1 1/4 inches long.
- Miyazaki toad lily (Tricyrtis hirta ‘Miyazaki’, USDA zones 4 through 8), which reaches about 30 inches in height with lavender-spotted white flowers up to 1 3/4 inch in size.
Site Toad Lilies
Toad lilies prefer a forest-type soil that is humus-rich and a bit acidic, with a pH between about 6.1 and 6.5. Place the plants in ground that is well-drained, but always maintains some moisture, setting them 1 to 1 1/2 feet away from each other.
In hot southern zones, give toad lilies deep shade. North of USDA zone 6, try to provide a little morning sun to push them into bloom before autumn frosts. Elsewhere, they will thrive in moderate shade.
Sustain Toad Lilies
Water toad lilies frequently enough that their soil never completely dries out.
Strong chemical fertilizers can burn their foliage, so feed them every other month from spring through fall with an organic fertilizer instead:
- For a 5-5-5 type, scratch about 1/2 cup of the granules into every 10 square feet of ground around the plants, but follow label directions.
- Alternatively, fertilize the plants every two weeks with a fish emulsion such as 2-4-1 at half strength, mixing 1 tablespoon of the concentrate into 1 gallon of water.
Safeguard Toad Lilies
A toad lily virus changes the color of the flowers to mottled purple and can be spread from plant to plant by aphids. Therefore, keep an eye out for green bugs resembling over-sized green lice, which cluster near the tips of the shoots. If you see any, wash them off the plants with a strong stream of water from a spray bottle or hose. Dig up and discard any plants affected with the virus.
Due to their preference for damp, shady conditions, toad lilies often fall prey to slugs too. To prevent those gastropods from chewing ugly holes in the foliage, scatter iron phosphate slug control pellets around the plants at a rate of about 1 teaspoon for each square yard. Apply them at least once every two weeks during the growing season, more frequently during rainy periods.