Q: Someone told me my lily of the valley is invasive. Is this true? Should I remove it?
— Cheryl from Poland
A: Well, it depends. At the very least, be warned that it does spread quickly and will fill in an area.
But, as Eric Barrett, the Extension educator for agriculture and natural resources, likes to say, it is not evergreen and thus the mice do not use it for cover in the winter. So, that’s one thing going for it.
If you don’t thin it every few years after it fills in an area, you will start to get disease on the leaves. So, if you keep it, plan to thin it when it begins to look like it needs some TLC.
There are different lily of the valley plants, though. Convallaria pseudomajalis is native to the southeast United States in the Appalachian mountains.
But you most likely have Convallaria majalis, which is a plant native to Europe. Additionally, there is a native plant that looks similar, but the flowers are different — not bell shaped and the leaves are smaller. It is called Maianthemum canadenseand a common name is false lily of the valley.
When it comes to plants that spread, you do need to be careful. Anything that others call a ground cover is something you might want to think twice about before planting it in your garden. Spreading plants can become invasive if they dominate the vegetation in a natural area.
As for me, lily of the valley is one of the sweetest and familiar smells of spring. Delicate little white (sometimes pink) bell-like blossoms fill the air with their sweet aroma. There is something about this plant that symbolizes pureness, hope and promise.
There are a few things about this deceiving little beauty we should all be aware. All parts can be poisonous, highly poisonous to animals and humans. The concentration of cardiac glycosides (which means it affects the heart muscle) can be deadly.
Lily of the valley is an herbaceous perennial that forms extensive colonies by spreading underground stems, or rhizomes. Theses stems spring forth in the spring.
As good as it smells, as nice as it is in a bridal bouquet which can be quite expensive, I don’t have time to clean it out every year or two in my garden. Yet, it is a hardy plant that attracts few pests and animals are smart enough to avoid this plant.
We can find this European native throughout the USA. It prefers part shade and some varieties need warm summers. Soils that are silty or sandy and acidic or moderately alkaline with a good amount of humus will make for ideal growing conditions. It will need water in dry spells, preferring moist but not soggy soil.
Temperatures between 60 and 70 degrees are ideal. This may be why large clumps may be found under trees. Fertilizer is not required unless the soil is exceptionally poor.
This plant has been used in folk medicine for centuries. In small amounts, it is said to “comfort” the heart and strengthen memory. However, no scientific evidence supports these claims.
As an old-time gardener my advice is to pass it on by for your yard. Instead, enjoy the wonderful fragrance that whiffs from your neighbor’s yard.
To learn more about this plant, go to http://go.osu.edu/lilyofthevalley.
To learn more about ornamental plants that spread in your garden and issues they may cause, go to http://go.osu.edu/spreadingplants
Marilyn McKinley is an OSU Extension Master Gardener Volunteer in Mahoning County. Call 330-533-5538 to submit your questions to our clinic. During the off season, questions can be submitted at any time. Details at go.osu.edu/mahoningclinic
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