Gardeners often struggle to remove persistent, aggressively spreading plants mistakenly called “Tiger Lilies.” The target plant is usually the Tawny Daylily, Hemerocallis fulva, which quickly colonizes garden space. Simple pulling often results in immediate regrowth, making complete removal a significant challenge. This guide details the specific methods required to permanently eradicate this perennial from your landscape.
Identifying the Target and Its Persistence
Understanding the underground structure of the Tawny Daylily is the first step toward effective removal. Hemerocallis fulva relies on thick, fleshy root systems, known as tubers or rhizomes, to store energy. These structures allow the plant to rapidly regenerate even after the foliage is cut down. A small fragment of a rhizome left in the soil contains enough stored carbohydrates to sprout a new plant. This regenerative capacity explains why surface-level removal techniques consistently fail.
Non-Chemical Elimination Methods
For removal without chemical agents, manual excavation provides a reliable, though labor-intensive, solution. The entire plant must be dug out, requiring deep excavation to reach the farthest extent of the root system. Dig at least twelve inches deep and a foot or more beyond the visible perimeter of the foliage clump. Meticulously sift through the excavated soil to ensure every piece of the white or tan tuber is removed.
Any fragment of the underground structure left behind will lead to recurrence, necessitating vigilance during digging. After initial removal, monitor the area closely for several weeks and immediately dig out any new sprouts that emerge. Repeating this manual removal process over a full growing season will deplete the remaining energy reserves and starve out any small, missed pieces.
Another non-chemical approach involves depriving the plants of sunlight through solarization or smothering. This method requires placing an opaque material, such as thick black plastic sheeting or heavy layers of cardboard, directly over the entire patch. The barrier must extend past the plant’s perimeter to prevent shoots from escaping around the edges.
Excluding light prevents photosynthesis, forcing the plant to use its stored energy reserves until they are exhausted. For this technique to be successful, the cover must remain in place for an extended period, often requiring a full growing season—approximately six to nine months—to completely kill the root structures.
Herbicide Application Strategies
When manual removal is impractical due to the size of the infestation, chemical control using systemic herbicides can be highly effective. Systemic products, such as those containing glyphosate, are absorbed by the foliage and transported throughout the plant’s vascular system, eventually reaching the tubers. The timing of the application is a major factor in ensuring the chemical reaches the root system.
Application is most effective during late summer or early fall (typically mid-August through September) when the plant is actively preparing for dormancy. During this period, the daylily naturally translocates carbohydrates from its leaves down to its roots for winter storage. Applying the herbicide then ensures the chemical is carried directly to the energy-storing tubers.
To improve the absorption rate, slightly wound the foliage or cut the leaves back to about six inches before treatment. For small, isolated plants, a targeted application involves painting the concentrated herbicide directly onto the cut stems or leaves using a foam brush. This precision application minimizes the risk of chemical drift and protects surrounding desirable plants.
A single application rarely achieves complete eradication due to the amount of stored energy in the root mass. Follow-up treatments are necessary, requiring repeat applications whenever new growth emerges. Waiting two to three weeks after the initial application before reapplying allows sufficient time for the chemical to move fully through the plant’s system.
Safe Disposal and Long-Term Monitoring
Properly disposing of the removed plant material is necessary to prevent accidental reintroduction elsewhere in the garden. The fleshy tubers and rhizomes can survive outside of the soil for extended periods. Do not add these parts to a home compost pile, as composting is often insufficient to kill them, and they may sprout once the compost is used.
Instead, the excavated root material should be placed into sealed, heavy-duty garbage bags and disposed of with household waste. If local regulations permit, another safe option is to thoroughly dry the material until brittle and then burn it, ensuring all regenerative capability is destroyed.
Following the initial removal effort, long-term monitoring of the treated area is required for complete success. New shoots can emerge for several seasons as the plant uses its last remaining reserves. Immediately removing these sprouts by hand or spot-treating them with a targeted herbicide prevents the plant from photosynthesizing and replenishing its underground stores, leading to total exhaustion.