Spiderwort, primarily aggressive Tradescantia species like Tradescantia fluminensis, is a common perennial groundcover that readily escapes cultivation to become a tenacious garden weed. This plant is notorious for its difficulty of eradication, which stems from its highly fragmented growth habit. Successfully removing spiderwort requires a persistent, multi-faceted approach that addresses both the existing mat and the plant’s ability to regenerate from even the smallest pieces.
Identifying the Problematic Spiderwort
Spiderwort is recognizable by its trailing, soft, hairless, succulent stems that form dense, interlaced mats on the soil surface. The oval-shaped leaves are typically dark green, smooth, and slightly fleshy. Small, white flowers with three petals appear in clusters, but the plant’s primary method of spread is vegetative, not by seed. Its aggressive nature is rooted in its ability to quickly develop new roots from nearly every node along a stem. Tiny stem fragments can easily break off during attempted removal and rapidly establish new infestations.
Manual and Cultural Removal Methods
For smaller infestations or areas where chemical use is a concern, manual removal offers a targeted solution, though it demands meticulous attention to detail. The initial step involves carefully raking, rolling up, or pulling the dense mats from the soil. This process requires deliberate movement to prevent the brittle, succulent stems from shattering into numerous small pieces that could re-root.
Once the bulk of the plant material is collected, the area must be thoroughly inspected for any remaining stems or root fragments, which must also be removed. Proper disposal is necessary to prevent re-infestation; do not compost the material. Instead, collected spiderwort should be bagged securely and disposed of in municipal waste or taken to a landfill. Alternatively, the plant material can be solarized by covering it with plastic sheeting until it is completely desiccated.
Cultural Suppression
For large areas, cultural methods can suppress the weed by limiting its access to light. Spiderwort is tolerant of shade, but a significant reduction in light inhibits its growth. Increasing the canopy cover or applying a thick layer of opaque material, such as black plastic sheeting or heavy cardboard covered with mulch, can smother large patches over time.
Effective Herbicide Control
When dealing with extensive or deeply established spiderwort infestations, a chemical approach is often the most practical method for widespread control. Standard herbicides often prove ineffective because the plant’s leaves possess a waxy cuticle that repels the spray solution. Using a non-ionic surfactant or an organosilicone wetter is recommended to help the herbicide penetrate the leaf surface and improve efficacy.
The systemic herbicide triclopyr is the most effective active ingredient for controlling Tradescantia species, often achieving 90% or greater control. Glyphosate-based products can also be used, though they are less potent, often yielding only 30% to 60% control in initial applications. If using glyphosate, a higher concentration, such as a 3% solution, is recommended for better results.
Herbicide application should be timed when the plant is actively growing to ensure the chemical is effectively translocated throughout the entire system, including the rooting nodes. Because of the plant’s high recovery rate, repeat applications are necessary to achieve total control. Monitor the area following the initial application and re-treat any persistent or new growth after two to three months to prevent the weed from recovering fully.
Post-Removal Management and Prevention
Successfully removing spiderwort is only the first phase; long-term prevention is necessary to keep the area clear of regrowth. The treated area must be monitored frequently, as the weed can emerge from missed stem fragments or dormant nodes for up to four years following initial removal. Any small new sprouts should be immediately removed by hand or spot-treated with a targeted herbicide application.
Preventing recurrence involves establishing a healthy, dense ground cover of desirable plants to outcompete any emerging spiderwort. Planting competitive species or encouraging native flora helps reduce light availability to the soil surface, which naturally suppresses spiderwort growth. Maintaining a dense layer of organic mulch also acts as a physical barrier against sunlight and inhibits the re-rooting of new fragments. If utilizing selective pre-emergent herbicides, be aware that their residual activity may temporarily delay the successful establishment of desirable seedlings.