Lily of the Valley Flowers

Fragrant but Invasive, Poisonous Landscaping Plants

Lily-of-the-valley flowers displaying their bell-like shape.
David Beaulieu

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. The plant is part of the asparagus family.

Traits of This Flower

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

In a zone-5 garden, C. majalis blooms for most of the month of 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 Needs

Native mostly to Eurasia, lily of the valley plants can be grown in planting zones 2-9. This puts them among the hardiest of perennials. When you buy some to plant them in your yard, they usually come as bulbous roots called "pips."

Plant them in a mostly shaded to partially shaded area (morning sun only). Grow them in a well-drained, loamy soil enriched with humus. 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.

The plants will generally survive in the North from whatever rainfall you receive, but you will get better flowering if you give them water during dry periods.

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 tend to spread more in the northern section of their range than in the southern section).
  1. They are poisonous plants, which is 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, so that any residue that you pick up is not transmitted to your food (should you forget to wash your hands before dining). All parts of the plant are considered poisonous if eaten. 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 winding 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 even if you grow just a small patch of this ground cover in your yard, you can easily picture yourself smelling the sweet fragrance of lily of the valley as you stroll along such a dream 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 together (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. Another nice thing about this ground cover is that it is deer-resistant and rabbit-resistant.

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. If flowering declines over time, you can divide these perennials in late fall to give them a fresh start.

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 these invasive plants in pots, to avoid having them spread (unless you want them to do so, of course). 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, the sort of barrier used to hem in running bamboo plants.

Spider mites and aphid pests may bother these plants at times. Keep an eye out for them so that you can act quickly. Early detection makes for an easier solution to this problem. At the first sighting of such pests, spray with organic Neem oil.

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. The rosea variety
  2. 'Fortin's Giant'
  3. 'Flore Pleno'
  4. 'Hardwick Hall'
  5. 'Albomarginata'
  6. 'Albostriata'

Their names go a long way towards describing the first two types of C. majalis. The first bears rosy-pink flowers, while the flowers on the second are larger than on the common type of lily of the valley. 'Flore Pleno' is valued for its double flowers. The last three are kinds that have variegated leaves. 'Hardwick Hall' has leaf margins in a chartreuse color. It is easy, at first, to confuse 'Albomarginata' and 'Albostriata' ("Albo" means "white"). But the former has white leaf margins, while the latter has white streaks throughout the leaf. You can remember this by looking for the "marginata" in 'Albomarginata.'  

The Invasive Nature of Lily of the Valley, Getting Rid of It

Anna Pavord, in her book, Bulb, quotes rock-garden expert, Reginald Farrer as saying, "The lily-of-the-valley is the worst of all delicious weeds when it thrives." The success of this sweet-smelling 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. It's difficult to eradicate such a colony. If you try digging it out, the smallest root left behind will produce 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 get rid of lily of the valley, in the first place.

So 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 pots or in high raised beds, where its access to the ground will be cut off.

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

Meaning of the Names

Convallaria comes from the Latin, convallis and means "valley." This is perhaps a reference to its ability to thrive in shady, wooded valleys. The species name, majalis means "of May" and refers to the blooming period for this flower in some regions. As for the common name, although it is called "lily of the valley," it is not a true lily. That is, it does not belong to the genus, Lilium. Lilies are so widely adored that the name has been loosely applied to many other plants, creating confusion for beginning gardeners.