Yellow trout lily is normally planted from corms in the late summer, or by seeds sown in late spring or early summer. It is a relatively slow-growing plant; root divisions may not flower until their second year, and seedlings can take as much as five or six years before they flower. Trout lily is best planted in a location where it can spread and naturalize. Plant them about 5 inches deep and 2 to 4 inches apart for a colony effect. When weeding around it, make sure not to damage the offset corms that develop, as these are the source of new plants. Many ants in or around the plants are a welcome sign because trout lily has a symbiotic relationship with ants—they spread the seeds and help the plant naturalize. After the foliage dies back in the summer, leave it in place as a natural mulch all through the winter.
Light
The best place to grow trout lily is an east-facing location with morning sun. In its native habitat, trout lily grows underneath deciduous trees such as oaks and maples. In the early spring, before the trees have leaved out, this setting provides ample sunlight, which the plants need to thrive and bloom. Later, during the summer, an ideal site has dappled shade to protect the plant from the hot midday and afternoon sun.
Soil
Trout lily can grow in any light, moist soil that is rich in humus, similar to the soil in its native habitat. Dense garden soils should be heavily amended with compost or peat moss to create an ideal environment. Soil pH should be on the acidic side, below 6.8.
Water
The plant needs moisture during its spring growing period, about 1 inch of water per week from rain or irrigation. In the summer, after trout lily has gone into dormancy, it requires drier conditions, and no watering is needed.
Temperature and Humidity
Yellow trout lily is hardy in zones 3 to 8, easily surviving temperatures as low as minus 30 degrees Fahrenheit. Native to forests and damp meadows, this plant handles humid conditions but will not tolerate extreme dry heat.
Fertilizer
This plant does not need extra fertilizer if it is planted in rich, humusy soil. Instead, top-dress with more organic matter each spring before the new growth starts.
Types of Trout Lily
Yellow trout lily does not have any widely available named cultivars, but the Erythonium genus includes several additional species that are collectively known as trout lilies. Among those that are often cultivated for garden use:
Erythonium almidum (white trout lily or white dogtooth violet) has white flowers with lavender-colored blotches. It is also native to the eastern U.S. and is hardy in zones 4 to 9.Erythonium dens-canis (dogtooth violet) is a native of southern Europe. It has rosy violet flowers and blooms in late spring. It is hardy in zones 3 to 8. Several named cultivars are available, including ‘Lilac Wonder’, ‘Pink Perfection’, and ‘Purple King’. Erythonium grandiflora (yellow glacier lily) is a considerably taller plant, growing to nearly 2 feet. Native to the Northwest, it blooms in late spring and is hardy in zones 4 to 8. It does not have the mottled leaves seen on the other species. Erythronium revolutum (pink fawn lily or mahogany fawn lily) has pink flowers on 12- to 14-inch plants. Native to the Pacific coast from Northern California to British Columbia, it is hardy in zones 5 to 8. ‘Pagota’ is a hybrid form with bright yellow flowers.
Propagating Trout Lily
Trout lily is very finicky to grow from seed so it’s best propagated by division of the offset corms. After several years, when the plants have grown into leafy clumps, it’s time to divide them. Here’s how:
How to Grow Yellow Trout Lily From Seed
It can take as much as five or six years to produce mature flowering plants when propagating yellow trout lily from seeds, so it’s rarely done except by developers seeking hybrids or by very serious amateurs looking to experiment. However, if you have sufficient space to develop a colony of yellow trout lilies, then you can direct sow seeds just as the seed capsules split in summer. In the initial season, no seedlings will be evident, but the following spring you will likely see the grass-like seedlings appear. But it will be at least two years before the plants are recognizable, and an additional two or three years until the plants blossom.
Potting and Repotting Yellow Trout Lily
This plant is best suited to colonizing in semi-shady woodland and meadow gardens. It is a spring ephemeral that does not lend itself well to container culture.
How to Get Yellow Trout Lily to Bloom
This plant typically produces (at most) a single drooping flower per stalk, with a bloom period that lasts about two weeks. The exact window for blooming varies depending on region, but usually falls somewhere between March and May. Not every plant will produce flowers stalks on any given year. A colony of yellow trout lilies will generally bloom reliably if planted in humus-rich soil in a partly shady location, but the plants do not respond well to dry soils or too much sun. Flowering is always somewhat modest, so don’t expect a dramatic display.
Common Problems With Yellow Trout Lily
A common complaint from gardeners unfamiliar with this plant is that it vanishes rather quickly after the flowering period is over. This is a common feature of all spring ephemerals, which leaves the gardener with the challenge of filling the empty area of the garden. This species is often planted along with ferns, summer snowflake, primroses, and other plants that enjoy shady conditions and can fill in after tout lilies have faded.
