Lily of the valley (Convallaria majalis) is not a true lily; It is actually part of the asparagus family, although its foliage is reminiscent of some lilies. Medium green leaves about 5 to 10 inches long and 1 to 3 inches wide arching from the center of a clump. Small, fragrant, white flowers emerge on long stems from leaf clumps in spring, and orange-red berries appear later in the fall if different varieties are planted for cross-pollination. Don’t be fooled by the delicate appearance of the bell-shaped flowers of the lily of the valley. It is a resistant plant cover that spreads gradually but persistently to form dense colonies.1
Lily of the valley can be planted by root divisions, potted nursery plants or seeds in the fall, although spring planting is also acceptable. It is considered invasive in much of the Midwest and Northeast, where planting may be discouraged or even prohibited. Please note that lily of the valley is toxic to humans, as well as dogs, cats, and horses.2 It contains glycosides and saponins that can cause cardiac symptoms and digestive upset if large quantities are ingested. Consumption of berries by children is the most common cause of poisoning and deaths are possible.
Common namesLily of the valley (Lily of the valley)
Botanical name Convallaria majalis
FamilyAsparagaceae
Plant typeHerbaceous, perennial
Adult size 6–12 inches tall, 9–12 inches wide
Sun exposurePartial, shade
Soil typeWell drained
Soil pHAcidic, neutral
Flowering TimeSpring
Flower ColorWhite
Hardiness zones 3–8 (USDA)
Native AreaEurope
ToxicityToxic to people, toxic to pets 2
Lily of the valley will grow vigorously almost anywhere with some shade. In fact, gardeners often use it under trees where many other plants do not grow due to shade. Plant the rhizomes about 6 inches apart with the growing buds buried about 1/2 inch deep.
This plant needs little attention to thrive once established. It is a long-lived plant that does not have serious pest or disease problems. Plan to water during dry periods. Additionally, if flowering has slowed on older plants, it is beneficial to dig them up and divide them to refresh their growth.
The lily of the valley reproduces by spreading rhizomes and you must carefully supervise it so that it does not escape its limits. Lily of the valley can spread quickly and cover a large area and may end up suffocating other nearby plants. The European native is considered an invasive plant in many parts of the Midwest and Northeast, and in some places it is even designated as a noxious weed.
Plant lily of the valley in partial sun to full shade. Direct morning sun is fine, but the plant needs protection from the harsh afternoon sun. And if you live in a warmer part of their growing zones, full shade is best.
Lily of the valley prefers soil rich in organic matter with good drainage. But it can grow in a variety of soil types, including clay soil. It likes an acidic to neutral soil pH, but can also tolerate slightly alkaline soils.
This plant prefers constantly moist but not soggy soil. Water whenever the soil begins to dry out due to lack of rain and/or hot weather. Soil that is too dry will prevent the growth and flowering of the plant.
Lily of the valley prefers mild conditions with medium humidity. Temperatures between 60 and 70 degrees Fahrenheit are best. The plant does not do well in dry, hot climates. And even in temperate climates, it could die during the hottest summer months. This usually will not kill the plant; usually returns the next spring.
Lily of the valley usually does not need any fertilizer unless the soil is poor. If your soil is lacking nutrients, you can add a slow-release granular fertilizer in the spring. To know the amount to use, follow the instructions on the product label.
In addition to the typical lily-of-the-valley species found in gardens, there are several named cultivars available, including:
There is no need to prune or wilt this plant. Allow the foliage to remain in place and decompose, providing natural mulch for plants.
Lily of the valley is very easy to propagate by dividing the roots in autumn or spring. Division serves both to create new plants and to rejuvenate old colonies that have become so thick that they no longer flower strongly. Here’s how to propagate by root division:
Growing from seeds is not common as propagation by root division is very easy. Growing lily of the valley from seeds is tricky and time-consuming, but if you want to grow a cultivar with an unusual name, it may be the most effective way to get plants. Seeds should be sown in late winter or early spring. Sow them in seedbeds or small pots, covered with a layer of compost and then with fine gravel. Bury the seed flat or potted in the ground in a shady location and keep moist. The seeds can take anywhere from two months to a full year to germinate and sprout. After the seedlings emerge, transplant them into individual pots and continue growing them for two more years. At this point, they can be transplanted to the garden in spring or fall.3
Perennials like lily of the valley are not typical container plants, but with this potentially invasive species, container growing can be a good way to keep the plant within defined boundaries. Lily of the valley can be easily grown in well-draining pots filled with standard potting mix. Containers can be made of any material.
Potted plants can be moved to a sheltered location for the winter. It is also possible to grow them as permanent houseplants, although they will need to be moved to a cool location for several weeks a year during the winter to allow for the necessary dormancy period. If given this annual dormant period, plants will flower indoors for about four weeks each year.
Garden plants do not require any protection from the cold in winter, but autumn is a good time to cover them with compost, which provides all the necessary annual feeding.
Pests that can affect lily of the valley include aphids and mites, which can be treated with horticultural oil or simply ignored while waiting for natural predators to arrive and handle them. Pest problems are almost never serious.
Common diseases include stem rot, various fungal leaf spots, and anthracnose, none of which are terribly serious. Affected plant parts can be removed and destroyed (do not compost, which may allow the transmission of spores).4
This plant typically blooms over a period of about four weeks, from mid-spring to early summer; The exact flowering period depends on your hardiness zone. Flowers usually do not need coaxing, but flowering in older colonies may begin to fade as clumps become dense and overgrow. Digging up and dividing the root clumps and replanting with a decent amount of space between them will encourage better flowering.1
This plant is best suited to regions with relatively cool summers, and declining foliage often results in hot summers, although the plants usually recover when the weather cools again. So if the foliage darkens during the summer, it is likely a natural reaction to warm weather; just keep plants well watered.
Lily of the valley can spread quite aggressively if grown under ideal circumstances. Consult local experts before planting and be prepared to do regular work to control the plant’s tendency to wander.
