Lily of the Valley (Convallaria majalis) is a beautiful, fragrant flowering plant often appreciated for its delicate white blooms. However, it can quickly become invasive, spreading rapidly through underground rhizomes and forming dense colonies that take over gardens and flower beds. Once established, this hardy plant can be difficult to remove. Whether you’re looking to control its spread or eliminate it completely, this guide will provide effective methods on how to get rid of Lily of the Valley and reclaim your garden space.
Why is Lily of the Valley So Difficult to Remove?
Lily of the Valley spreads through an extensive underground rhizome system, allowing it to colonize large areas rapidly. Each rhizome segment can produce new shoots, making it incredibly persistent and hard to control. Even if you pull the visible parts of the plant, the rhizomes often remain in the soil, continuing to grow and spread.
To effectively get rid of Lily of the Valley, you’ll need a combination of patience, physical removal, and possibly chemical treatments, depending on the severity of the infestation.
Non-Chemical Methods to Remove Lily of the Valley
If you prefer to avoid chemicals in your garden, there are several natural methods to remove Lily of the Valley. While these methods may take more time and effort, they can be effective if done consistently.
1. Digging Up the Plants
Manual removal is one of the most effective non-chemical ways to eliminate Lily of the Valley, but it requires persistence to ensure all rhizomes are removed.
Step-by-Step Guide:
- Loosen the soil: Use a garden fork or spade to gently loosen the soil around the plants. Be careful not to break the rhizomes, as any leftover fragments can regrow.
- Dig up the roots: Remove the entire root system, including the rhizomes, as thoroughly as possible. Dig deep (6-8 inches) to ensure you reach all the rhizomes.
- Dispose of the plants: Do not compost Lily of the Valley, as its rhizomes may survive and sprout again. Instead, bag the plants and roots and dispose of them in the trash.
- Repeat as necessary: Even with careful digging, some rhizomes may remain in the soil. Regularly check for new growth and dig up any shoots as soon as they appear.
2. Smothering the Plants
Smothering Lily of the Valley deprives it of sunlight, which eventually weakens and kills the plants. This method works best for larger areas where digging might not be practical.
How to Smother Lily of the Valley:
- Mow or cut back the plants: Before covering the area, mow or cut the plants back to ground level.
- Cover the area: Lay down a thick layer of black plastic, landscape fabric, or cardboard over the infested area. This creates a barrier that blocks sunlight and prevents photosynthesis.
- Weigh it down: Secure the covering with rocks, bricks, or landscape pins to keep it in place.
- Leave it covered: Keep the area covered for at least one full growing season, or longer, to ensure the rhizomes are completely dead.
- Check periodically: Occasionally lift the covering to check for new growth. If shoots appear, either dig them up or continue covering them.
3. Solarization
Solarization uses the sun’s heat to kill Lily of the Valley rhizomes. It’s particularly effective in sunny areas and during the hot summer months.
How to Solarize:
- Mow the plants down: Cut the plants down to ground level.
- Cover with clear plastic: Use a clear plastic tarp, as this will allow sunlight to penetrate and heat the soil underneath.
- Seal the edges: Bury the edges of the plastic with soil to trap heat inside.
- Leave the plastic in place: Keep the plastic in place for 4-6 weeks during the hottest part of the summer. The heat will “cook” the rhizomes, killing the plants below.
Chemical Methods to Remove Lily of the Valley
If manual removal and non-chemical methods are not effective, you may need to use herbicides. When using chemicals, it’s important to apply them carefully to avoid harming nearby plants and the environment.
1. Using Glyphosate-Based Herbicides
Glyphosate is a broad-spectrum herbicide that kills plants by targeting their root systems. It’s highly effective at killing tough, invasive plants like Lily of the Valley but must be applied carefully.
How to Apply Glyphosate:
- Cut the plants: Mow or cut back the Lily of the Valley plants to just above the ground. This exposes fresh cuts, allowing the herbicide to penetrate more easily.
- Spray or paint the herbicide: Apply a glyphosate-based herbicide directly to the cut leaves or stems. Be careful not to spray it on nearby desirable plants.
- Reapply if necessary: Some areas may require multiple applications, especially if the infestation is large. Repeat the process if new shoots appear.
- Wait for results: Glyphosate typically takes 2-3 weeks to show results. During this time, the chemical will travel to the root system, killing the plant from the roots up.
2. Triclopyr Herbicide
Triclopyr is another herbicide that works well on woody and broadleaf plants like Lily of the Valley. It’s often used in areas where glyphosate isn’t as effective or where you want to target specific plants without harming grasses.
How to Use Triclopyr:
- Cut back the plants: Just like with glyphosate, cut the Lily of the Valley down to ground level.
- Apply the herbicide: Spray or paint the herbicide on the exposed leaves or stems, making sure to thoroughly coat the plant.
- Monitor the area: Triclopyr may require repeated applications over the course of a few months to ensure all rhizomes are killed.
Preventing Regrowth
Once you’ve successfully removed Lily of the Valley, it’s important to take steps to prevent it from coming back. This can be particularly challenging if the plant has established itself in your garden for a long time.
1. Regular Monitoring
Even after you’ve removed the visible parts of the plant, small rhizomes or seeds may remain in the soil. Regularly monitor the area for new shoots and remove them immediately before they have a chance to establish.
2. Mulching
Applying a thick layer of mulch can help suppress any remaining Lily of the Valley rhizomes and prevent them from sprouting. Organic mulches like wood chips or straw work well to block sunlight and inhibit growth.
3. Planting Ground Covers
Consider planting dense ground covers or other plants that can outcompete any remaining Lily of the Valley. Ground covers like Vinca, ivy, or pachysandra can fill the space and help prevent the regrowth of invasive plants.
4. Keep the Soil Disturbed
If you notice any small shoots trying to re-emerge, disrupt the soil in that area by digging or tilling. This will help expose the rhizomes and make it harder for them to re-establish.
Conclusion
Getting rid of Lily of the Valley can be a challenging task, but with persistence and the right methods, it’s entirely possible to control or eliminate this invasive plant. Whether you choose manual removal, smothering, solarization, or herbicides, it’s important to stay consistent and check for regrowth regularly. With a combination of these strategies, you can restore balance to your garden and prevent Lily of the Valley from taking over.
FAQs
- How long does it take to get rid of Lily of the Valley? It depends on the method used and the severity of the infestation. Manual removal and non-chemical methods can take several months to a year, while herbicides may work more quickly.
- Can I compost Lily of the Valley? No, it’s best to avoid composting Lily of the Valley, as its rhizomes and seeds may survive and spread through your compost pile.
- Is Lily of the Valley poisonous? Yes, all parts of the Lily of the Valley plant are toxic to humans and pets if ingested. Always handle with care, especially when removing large quantities.
- Will mulch stop Lily of the Valley from growing back? Mulch can help suppress the regrowth of Lily of the Valley, especially when combined with other removal methods like digging or smothering.
- Can I use vinegar to kill Lily of the Valley? Vinegar can be used as a natural herbicide, but it may not be strong enough to kill deep-rooted plants like Lily of the Valley. It’s more effective on small, young plants.
- What is the most effective herbicide for Lily of the Valley? Glyphosate and triclopyr are the most effective herbicides for killing Lily of the Valley. Be sure to apply them according to the label instructions for the best results.