Lily of the valley (Convallaria majalis) is a beautiful but invasive plant that can quickly overtake your garden if left unchecked. Its ability to spread through underground rhizomes makes it difficult to control, and its toxicity adds another layer of complexity when trying to remove it. This guide will walk you through the most effective methods to get rid of lily of the valley and prevent it from coming back, from manual removal to using chemical and organic solutions.
Why is Lily of the Valley Difficult to Remove?
Lily of the valley is notorious for its rapid spread, mainly due to its underground rhizomes, which allow the plant to propagate and form dense colonies.
- Invasive Growth Patterns: The plant spreads by sending out rhizomes (underground stems) that can extend far from the original planting site, creating new shoots and quickly filling any available space.
- Spreading Through Rhizomes: Even small sections of the rhizome can grow into new plants, making it important to remove as much of the root system as possible.
- Toxicity to Other Plants and Animals: The plant is toxic to humans and pets if ingested, and its dense growth can choke out other plants in your garden, reducing biodiversity.
Identifying Lily of the Valley in Your Garden
Before you can remove lily of the valley, it’s important to correctly identify it.
- Physical Characteristics: Lily of the valley is known for its broad, green leaves that grow in pairs and its bell-shaped, fragrant white flowers. It also produces small red berries in late summer or early fall.
- Recognizing Early Stages of Growth: Early in the season, lily of the valley produces shoots that emerge from the soil in clumps. These should be removed as soon as possible to prevent the plant from spreading further.
When is the Best Time to Remove Lily of the Valley?
Timing is crucial when trying to remove lily of the valley. While it can be removed at any time of year, certain seasons offer the best results.
- Ideal Seasons for Removal: The best time to remove lily of the valley is in spring or fall when the soil is moist, making it easier to dig up the rhizomes. Spring removal also targets the plant before it starts spreading.
- Why Early Intervention is Important: Removing the plants before they set seed or send out more rhizomes can prevent them from spreading further.
Manual Methods for Removing Lily of the Valley
Manual removal is one of the most effective ways to get rid of lily of the valley, but it requires patience and attention to detail.
- Digging Up the Plants: Use a garden fork or spade to carefully dig around the plant, ensuring you get as much of the rhizome system as possible. The goal is to avoid breaking the roots, as even small pieces can regrow.
- How to Remove Rhizomes: Dig deeply, about 6-8 inches down, to ensure you get the entire root system. After digging up the plants, sift through the soil to remove any remaining rhizome fragments.
- Tools Needed for Effective Manual Removal: A sharp spade, garden fork, and gloves are essential. Use the spade to cut into the soil around the plant and the fork to lift it out, breaking up the soil as you go.
How to Smother Lily of the Valley with Mulch
Smothering lily of the valley is another effective method, especially if you want to avoid using herbicides.
- Using Black Plastic or Landscape Fabric: Cover the infested area with black plastic or heavy landscape fabric to block out sunlight. This method prevents photosynthesis, starving the plant.
- Steps for Effective Smothering: First, trim the lily of the valley as close to the ground as possible. Then, cover the area with plastic or fabric, ensuring that it extends several feet beyond the infestation to prevent rhizomes from spreading out.
- How Long to Leave the Barrier in Place: Leave the plastic or fabric in place for at least one growing season (6-12 months). Check periodically to ensure that no new growth is emerging from the edges.
Chemical Methods for Removing Lily of the Valley
For more extensive infestations, chemical herbicides may be necessary. However, caution is needed to protect surrounding plants and soil health.
- Best Herbicides for Lily of the Valley: Glyphosate-based herbicides are effective against lily of the valley. Apply the herbicide directly to the leaves and allow it to be absorbed into the plant’s system to kill the rhizomes.
- How to Safely Apply Chemicals: Wear protective gear and apply herbicide on a calm, dry day to avoid drift. Be careful not to spray desirable plants, and follow the manufacturer’s instructions for safe application.
- Protecting Surrounding Plants from Herbicide: Use cardboard or plastic to shield nearby plants from overspray. You can also apply the herbicide using a brush for more targeted application.
Natural and Organic Alternatives to Herbicides
For those who prefer non-chemical methods, there are natural ways to kill lily of the valley, though they may require more persistence.
- Vinegar and Salt Solutions: A mixture of vinegar, salt, and dish soap can be sprayed directly onto the leaves. The vinegar dries out the plant, while the salt disrupts water absorption.
- Boiling Water Method: Pouring boiling water over the plants can kill the above-ground parts of the lily of the valley. Repeated applications may be necessary to weaken the rhizomes over time.
- Effectiveness of Organic Solutions: Organic methods may not be as fast or effective as chemicals, but with persistence, they can help control small infestations.
How to Prevent Lily of the Valley from Returning
After removing lily of the valley, it’s important to take steps to prevent it from coming back.
- Monitoring Regrowth: Regularly inspect the area for any signs of new growth. Remove any emerging shoots immediately to prevent the plant from re-establishing.
- Regular Garden Maintenance: Keep the garden well-maintained, and avoid allowing bare soil where lily of the valley can take hold again.
- Planting Ground Covers or Grass: To outcompete lily of the valley, consider planting dense ground covers or grass that can choke out any remaining rhizomes.
Pruning and Mowing to Control Lily of the Valley
If manual or chemical removal isn’t possible, mowing or cutting back the plants can help control them over time.
- When and How to Mow or Prune: Mow or prune the plants frequently during the growing season to weaken them. Over time, this can reduce their vigor and limit spread.
- Managing Small Infestations: For smaller patches, regular pruning combined with other methods like smothering can be effective.
- Regular Cutting to Weaken the Plant: Repeated cutting stresses the plant by preventing it from photosynthesizing and storing energy, eventually reducing its ability to spread.
Disposing of Lily of the Valley Safely
It’s important to properly dispose of lily of the valley debris to prevent regrowth.
- Why You Shouldn’t Compost the Plants: Don’t compost lily of the valley, as rhizomes or seeds can survive the composting process and spread to other areas of your garden.
- How to Dispose of Rhizomes and Plant Debris: Bag the plant material and rhizomes and dispose of them in the trash. Avoid dumping them in natural areas where they could take root again.
Dealing with Large or Established Lily of the Valley Patches
Removing large or well-established patches of lily of the valley can be challenging and may require a combination of methods.
- Strategies for Large-Scale Removal: For extensive infestations, start with manual removal, followed by chemical or organic treatments to target any regrowth.
- Combining Methods for Best Results: Use a combination of digging, smothering, and chemical treatments for the most thorough removal. Persistence is key, as it can take several seasons to fully eradicate the plant.
- Professional Removal Services: If the infestation is too large or persistent, consider hiring a professional landscaper or garden service experienced in removing invasive species.
How to Protect Other Plants While Removing Lily of the Valley
It’s essential to protect surrounding plants during the removal process to prevent damage.
- Shielding Desirable Plants During Removal: Use physical barriers like cardboard or plastic to shield nearby plants from herbicide drift or digging.
- Selective Herbicide Application: When using herbicides, apply them carefully to the lily of the valley leaves only, using a brush or targeted spray to minimize damage to nearby plants.
- Minimizing Soil Disturbance: Be careful not to disturb the soil too much when digging up the lily of the valley, as this can damage the roots of other plants or encourage further spread.
Common Mistakes to Avoid When Removing Lily of the Valley
Avoid these common pitfalls when trying to remove lily of the valley from your garden.
- Not Removing the Entire Root System: Simply cutting the plant back won’t prevent it from growing again. You must remove as much of the rhizome system as possible.
- Over-Reliance on One Method: Using only one removal method, such as herbicides, may not be enough. Combining techniques like manual removal and smothering increases your chances of success.
- Using the Wrong Herbicide: Some herbicides are ineffective against rhizome-spreading plants like lily of the valley. Be sure to choose a systemic herbicide that targets both the leaves and the root system.
Frequently Asked Questions About Removing Lily of the Valley
- How long does it take to eradicate lily of the valley? It can take multiple seasons to fully remove lily of the valley, as the rhizomes are persistent and may regrow even after initial removal.
- Can I prevent it from spreading without removing it? Regular mowing or pruning can control the spread, but it won’t completely eliminate the plant. Complete removal is necessary to prevent further infestation.
- What plants can replace lily of the valley? Consider replacing lily of the valley with non-invasive ground covers like creeping thyme, ajuga, or pachysandra, which can fill the space and prevent weeds.
Conclusion
Getting rid of lily of the valley can be challenging, but with persistence and the right approach, you can successfully remove this invasive plant from your garden. Whether you choose manual removal, chemical treatments, or natural alternatives, the key is to remain vigilant and prevent the plant from re-establishing. By following the steps outlined in this guide, you’ll be able to restore balance to your garden and enjoy a lily-of-the-valley-free landscape.