Lily of the valley is a low-maintenance ground cover that is hardy in USDA plant hardiness zones 2-7. It’s a popular perennial garden plant as well as a sought-after cut flower that is often used in bridal bouquets. Ironically, while its tiny bell-shaped white flowers have the most amazing fragrance, every part of the plant is highly toxic.
Generally, the lily of the valley plants bloom in spring, and its delicate, fragrant flowers can be seen and smelt for at least 3-4 weeks. Even though it is a garden plant, you can also grow the lily of the valley indoors. When grown as a potted plant indoors it often blooms out of season.
What time of year does the lily of the valley bloom?
Most lilies (ilium) bloom from early summer to fall. But there are early, mid-season, and late varieties, so you can mix and match to enjoy lily blooms from spring until the first frost in late fall or early winter.
Lily of the valley (Convallaria majalis), isn’t a true lily. You may be surprised to learn that it is part of the asparagus family, even though its leaves look similar to those of true lilies. But the flowers are totally different.
Also, true lilies can be anything from 2-4 feet tall, depending on the species. Lily of the valley is a low-growing plant that doesn’t get any more than 6-12 inches tall.
Growing lilies of the genus Lilium is quite different from growing lily of the valley. Apart from anything else, true lilies grow from onion-like bulbs, while lily of the valley grows from rhizomes that are underground stems.
In most places, the lily of the valley blooms from early to mid-spring, which is from March to April. Depending on when the blooms first appear, you can expect them to continue to bloom for at least a month. This means that you can expect them to bloom through the spring and summer months.
They become dormant in the fall, when many true lilies are still blooming, and right through the winter months.
Factors that prevent the lily of the valley from blooming
If your lily of the valley plants don’t bloom when they should, it isn’t rocket science to realize that they aren’t getting what they need. Either that or you’ve planted them in a location or in soil that they don’t like.
Temperature, light, and moisture all play an important role.
Temperature
Lily of the valley can be grown just about anywhere in the U.S., from zone 2-9. But it doesn’t do well in zones 9 and higher, where the winters are warm.
This is simply because it doesn’t get a decent dormant period in the winter months. Ultimately, its flowers are the best in areas that have cold winters.
So, if you live in one of the higher USDA zones, you will likely find that your lilies don’t bloom as you hoped they would – if at all.
Generally, they prefer average humidity with temperatures that are between 60-70°F (15-21°C). If it gets very hot in winter, the plants may die back, but they will usually come back to life when the temperature cools down.
Light
Lily of the valley likes to be in partial rather than full shade. They will grow in full shade, but they usually won’t produce many flowers.
While it doesn’t like the full sun all day long, it tolerates direct morning sun.
Moisture
They prefer soil that is loose and moist, but not wet and soggy. If the soil dries out, it will affect the growth of the plant and might prevent it from flowering.
If the weather is consistently dry, increase your watering regime. But don’t worry too much. Once the plants are well-established they become relatively drought tolerant.
How long does the lily of the valley bloom?
Lily of the valley will normally keep blooming for about 3-4 weeks, well into summer. The tiny bell-shaped flowers are usually white, but some types produce very pale pink or lilac flowers.
Some less common types have rosy pink flowers or double flowers. There is also an interesting species that has a yellow outline to its green leaves, and another has white streaks through its leaves.
Even though they only flower for about a month, the plant produces attractive orange-red berries in the fall that will add color to your garden. These are inedible for animals and humans, see Are Lily of the Valley Flowers Toxic, below.
In the fall, the leaves will turn a lovely golden hue.
How do you get the lily of the valley to bloom?
As mentioned above, the lily of the valley needs certain conditions to thrive. If these aren’t right, you might have a bed of lush, green-leaved plants, but no flowers.
If you start by planting them in the right environment, there’s no reason why they shouldn’t bloom.
Location
Lily of the valley grows just about anywhere that is shady. It usually does well under trees where most other plants won’t grow.
In fact, there’s more danger it will spread and overtake large areas in your garden. The problem is that this doesn’t guarantee that they will bloom!
Soil
Apart from the shade, you need to ensure that you plant your lilies of the valley in soil that drains well. While it will grow in a wide range of soil types, it prefers an acidic to neutral pH.
Dig compost into the soil before you plant. You can also add an all-purpose, slow-release granular fertilizer to improve the quality of the soil, but this isn’t usually necessary.
Planting
You can plant lilies of the valley from rhizomes or bare roots. Dig small holes large and deep enough to accommodate the bare roots and/or rhizome.
Be sure to space the plants about 6 inches apart.
Whether you are planting bare roots or rhizomes, make sure that the pointed buds called pips face upwards. Spread the roots out in the hole and fill them with soil. The pips should be about half an inch below the soil surface.
Water your plants thoroughly once you have planted them.
Care
Once they are established, the lily of the valley plants needs very little care. But until they are established, make sure that the soil stays moist and doesn’t dry out.
Why is my lily of the valley not blooming?
Lily of the valley doesn’t need a lot of care. It’s a perennial, so you stick it in the ground and it usually comes back year after year during the growing season.
Well, maybe, but it’s not that simple. You do need to be sure that you have planted your lily of the valley plants in moist, loose soil. It also prefers partial shade.
If you’ve done everything right, it might just be that your lily of the valley plants is not fully established. If not, try giving them a bit more time to get their root systems established.
Another reason they aren’t blooming might be because the bed is too crowded.
Or you may have used a fertilizer that has a high nitrogen content. Nitrogen will promote the growth of foliage, not its flowers.
What to do if the lily of the valley doesn’t bloom?
We’ve talked about the various reasons for the lily of the valley not blooming.
Aerating the soil with a garden fork could help if the soil has become too compacted,. If the bed is too crowded, the solution here is to thin the bed out late in summer or in early in the fall.
Give them more water if conditions are very dry. If you’ve planted them in a sunny spot, your best bet may be to dig up the rhizomes and replant them in the shade.
Are lily of the valley flowers toxic?
Every part of the lily of the valley flowers is toxic, including the flowers and the berries. The Pennsylvania State University’s College of Agricultural Sciences PennState Extension warns that the plant contains cardiac glycosides that can cause cardiac malfunction.
Wild animals won’t try to eat it, but domestic pets and children might pull it out of the ground. It’s unlikely they will eat it, but dogs especially might bite it and if they ingest it they could get very sick.
Conclusion
Lily of the Valley is a spring-flowering plant that produces very small, fragrant, bell-shaped flowers. It’s a hardy perennial that makes an attractive ground cover in shady areas.
These garden tips focus on ways to ensure that your lily of the valley plants blooms, and what to do if they don’t. We have also included tips that will help you to plant and grow them successfully in the right conditions.
Lily of the valley can be grown just about anywhere. Better still, it needs minimal maintenance and care.
It’s an excellent choice for any shade garden or shady spot where other plants won’t grow.