Lily of the Valley Flowers

Fragrant but Invasive, Poisonous Landscaping Plants

Lily-of-the-valley flowers displaying their bell-like shape.
Lily-of-the-valley has fragrant, bell-shaped flowers. David Beaulieu

Taxonomy and Botany of Lily of the Valley

Plant taxonomy classifies lily of the valley flowers as Convallaria majalis. The common name is often hyphenated.

Lily of the valley is an herbaceous perennial.

Characteristics of This Flower

A lily of the valley plant sends up a single flower stalk populated by as many as 12 or more waxy, white flowers. The fragrant flowers are nodding, bell-shaped, and have scalloped edges.

In a zone-5 garden, C. majalis blooms for most of the month of May. Indeed, the specific epithet, majalis means "pertaining to May." Green berries may succeed the blossoms, later ripening to red or orange. Vegetation consists of two basal leaves. The hosta-like leaves are upright, glossy green, and taper to a point, reaching a length of 6-9 inches, with a width of 4 inches. The plants spread via underground stolons and rhizomes.

Planting Zones, Native Origin, Sun and Soil Requirements

Indigenous mostly to Eurasia, lily of the valley plants can be grown in planting zones 2-9.

Plant them in a mostly shaded to partially shaded area (morning sun only). Grow them in a well-drained, loamy soil enriched with humus. Since lily of the valley flowers prefer moist, cool conditions, the shade requirement needs to be taken more seriously the further south you get in their range.

Warnings About Growing Lily of the Valley

There are two reasons not to grow Convallaria majalis plants:

  1. They are invasive plants in parts of North America (they are reputedly more aggressive in the northern section of their range than in the southern section).
  2. They are poisonous plants -- a concern if you have children or pets in the yard.

Concerning the toxicity of lily of the valley plants, experts advise wearing gloves when handling them, lest any residue be transmitted to your food (should you forget to wash your hands before dining).

All parts of the plant are considered poisonous if ingested. Symptoms of poisoning include stomach ache and blurred vision.

Uses for These Fragrant Flowers in Landscaping

One of the most fragrant plants, lily of the valley is the sort of ground cover that you may want in a border for a path of garden stepping stones wending its way through a remote corner of a large woodland garden. Of course, those of us who live on small properties can only dream of that. But one may well picture oneself inhaling the sweet fragrance of lily of the valley wafting up as one strolls along such a path on a perfect May day. Other plants with very fragrant flowers include:

  1. Common lilacs
  2. Korean spice viburnum
  3. Daphne
  4. Peonies
  5. Bearded iris
  6. English lavender
  7. Roses

To be enjoyed to their fullest, the plants should be massed (the flowers being small). The plant is also used in rock gardens and moon gardens, for cut flowers and weddings, and in medicines and perfumes.

Care for Lily of the Valley

Mulch to maintain soil moisture throughout the summer. Because these plants prefer a rich soil, apply compost each fall.

The above chores, however, will be the least of your problems with C. majalis. Your biggest problem will be keeping it from spreading where you don't want it.

Consider growing the plants in pots, to counteract their invasive tendency. Or if you must grow them directly in the ground in your garden, one way to prevent their spread would be to use landscape edging or, better yet, a bamboo barrier.

Types of Lily of the Valley

In addition to the typical lily of the valley flowers found in gardens, you may come across some less common types; for example:

  1. C. majalis var. rosea
  2. C. majalis 'Fortin's Giant'

Their names go a long way towards describing the above two types of C. majalis. The first bears pink flowers, while the flowers on the second are larger than on the common type of lily of the valley. You can also find kinds that have variegated leaves.

The Invasive Nature of Lily of the Valley

Anna Pavord, in her book on flower bulbs, quotes rock garden expert, Reginald Farrer as remarking, "The lily-of-the-valley is the worst of all delicious weeds when it thrives." The success of the perfumy invader comes at the expense of any other plants you may be growing in the same flower bed: C. majalis will crowd them out, thanks to the vigor of its spreading underground plant parts.

This plant establishes a colony, or "monoculture. It's difficult to eradicate such a colony: If you try digging it out, the smallest root left behind will generate more plants. One option, after digging out everything that you can, is to cover the affected area with a tarp for a year or so. Afterwards, faithfully remove any stubborn holdovers that surface.

Of course, the preferred approach is not to put yourself in the position of having to eradicate lily of the valley, in the first place. Consequently, the best advice is either not to plant it at all, or, if you do, plant it in an area of your landscape where you won't mind having it take over. One alternative is to plant it in containers or in high raised beds, where its access to the ground will be cut off.

Aficionados of native plants in eastern North America may wish to substitute with wild lily of the valley, also known as "Canada mayflower" (Maianthemum canadense).