Description

Convallaria majalis is an herbaceous perenniala plant whose growth dies down annually but whose roots or other underground parts survive plant that often forms extensive colonies by spreading underground stems called rhizomes. New upright shoots are formed at the ends of stolons in summer, these upright dormant stems are often called pips. These grow in the spring into new leafy shoots that still remain connected to the other shoots underground. The stems grow to 6–12 inches tall, with one or two leaves 4–10 inches long; flowering stems have two leaves and a raceme of five to fifteen flowers on the stem apex.

The flowers have six white tepals (rarely pink), fused at the base to form a bell shape, 0.2–0.4 inches in diameter, and sweetly scented; flowering is in late spring, in mild winters in the Northern Hemisphere it is in early March. The fruit is a small orange-red berry 0.2–0.3 inches in diameter that contains a few large whitish to brownish colored seeds that dry to a clear translucent round bead 0.04–0.12 inches wide. Plants are self-incompatible, and colonies consisting of a single clone do not set seed.

Habitat

Lily of the valley can tolerate full sun to full shade but prefers partial shade. Rich well drained moist soil is its preference.

Threats

Lily of the valley is not widely classified as a noxious invasive in most areas, but should be planted with care as it will spread and act. Lily of the valley forms dense monocultures on the forest floor and in our area out-competes and eliminates the native herbaceous species such as wild lily of the valley (Maianthemum canadense), wild oats (Uvularia sessilifolia), and violets (Viola spp.).

Dispersal Methods

Lily of the valley spreads quickly because of rhizomes which can form extensive colonies.

Control

Mechanical

Although the best time to remove the unwanted plants is after they finish blooming, you can dig them anytime. Because all parts of the Lily of the Valley are poisonous, be sure to wear gloves when you are pulling the plants and rhizomes. These contain toxins which will irritate the skin.

Use your garden spade to dig up the plants and rhizomes then use the rake to remove any pieces. You should sift through the soil with gloved hands to be sure and remove smaller pieces the rake missed. In order to eliminate the unwanted plants, you must completely remove the rhizomes. Even the tiniest portion of a rhizome can produce pips.

Then bag up the unwanted material and dispose of it as yard waste. Above all, do not compost this material!

Smothering is another effective organic way to get rid of the lily of the valley. This can be done in early spring when the plant starts to sprout. 

First, make sure to cut any mature plants as close to the ground as possible. Then, lay down a landscaping fabric, cardboard, a tarp, old carpet, or several layers of moistened newspaper over the entire area where the lily of the valley grows.

The second step is to weigh down the used material with anything like mulch, gravel, soil, or cinder blocks to hold it down in place. Leave the cover for an entire growing season. All the seedlings and the rhizomes should be dead by the end of the season. 

Chemical

You can also use a non-selective herbicide that contains glyphosatea widely used herbicide that can kill certain weeds and grasses, it works by blocking an enzyme essential for plant growth, such as RoundUp. You can spray the plants with the herbicide several times as needed. To be most effective, spray the plants early in the spring as the plants are flowering. We recommend spraying lily of the valley and then re-applying in two weeks, as it’s known to be a tough plant and might need two applications to kill all of it. Before applying the herbicide, read the label and apply it according to the product’s instructions.