Winning the War on Tradescantia: A Gardener's Strategic Guide to Wandering Willy...
Tradescantia fluminensis is one of the most resilient and invasive ground covers a gardener can face. Its lush, vibrant green appearance belies a frustratingly effective survival mechanism that thwarts most conventional weeding efforts. Pulling it often makes the problem worse. Digging it out is painfully slow.
This guide provides a strategic plan for controlling and eradicating Tradescantia by explaining why it's so difficult and how to defeat it.
Enemy Profile: Identification
- Botanical Name: Tradescantia fluminensis
- Family: Commelinaceae (commelina)
- Also Known As: Wandering Willie, Wandering Jew (perjorative)
- Originally From: South America
Before you can fight it, you must identify it.
Tradescantia is a trailing, soft, perennial groundcover. Its most telling features are the succulent, creeping stems that root at all nodes touching the ground. The leaves are dark green, shiny, smooth, and slightly fleshy, typically 3-6 cm long and oval with pointed tips. In New Zealand and similar climates, it may produce small clusters of white, 3-petalled flowers (around 2 cm in diameter) but typically does not produce fruit or seed.
Variegated and purple-backed leaf cultivars are common in gardens but readily revert to the more aggressive, solid-green form. It can be confused with Zebrina or Commelina species.
Know Your Enemy: The Science of Survival
Success depends on understanding your opponent. Tradescantia’s power comes from its brilliant, simple survival strategy: vegetative reproduction.
The plant's primary goal is to spread by fragments. Its stems are brittle and succulent, designed to break easily. Every single piece of stem that contains a node (the small bump where a leaf emerges) can grow new roots and create an entirely new, independent plant. When you pull a handful, you are often unknowingly breaking off dozens of fragments that fall back to the soil and re-root.
This creeping, mat-forming habit allows for rapid establishment. It is incredibly tolerant of dense shade, severe damage, wet soil, and a wide range of temperatures. Its only significant weaknesses are frost and severe drought.
This plant doesn't need seeds to travel; it spreads when stem fragments are moved by water, livestock, dumped vegetation, soil movement, or even stuck to boots and lawnmowers.
Why Spiderwort Must Be Removed
Tradescantia isn't just a nuisance; it's an ecological threat. It smothers the ground in light to deep shade, forming a dense mat that prevents the seedlings of native species from establishing. This effectively chokes out new growth and opens up habitats to invasion by other exotic shrubs and vines.
In riparian areas, mats growing on riverbanks can break away during high water flow, contributing to blockages and potential flooding. Furthermore, Tradescantia can cause severe dermatitis in dogs and other animals that walk through it. It is most likely to invade damp, shaded habitats, especially disturbed forest, shrubland, streamsides, river systems, and wetlands.
Top 5 Strategies for Eradicating Tradescantia (Wandering Willy)
1. Meticulous Manual Removal (The Physical Method)
This is the most effective organic method for small or new patches, but it requires absolute precision.
The Approach:
Do not simply pull the stems from above. You must lift the entire mat of the plant from underneath, ideally during a dry or drought period when the plant is weaker.
How-To Guide:
Place a large tarp or plastic sheet on the ground directly beside the infestation. Use a garden fork or rake to slide under the mat of weeds, working from the top of the catchment downwards. Lift the entire carpet of Tradescantia (stems, roots, and all) onto the tarp to contain the fragments. Once the main mat is gone, you must meticulously rake the cleared soil to find and remove every last piece of stem.
The Science Behind It:
This "lift and tarp" method prevents the plant's primary weapon, fragmentation, from being used against you. By lifting the mat whole, you keep the plant intact and ensure all pieces are transferred to the tarp for disposal. Follow-up spray is often required.
2. Light Deprivation (The Smothering Method)
This is a highly effective, non-chemical approach for larger, established areas. It is a slow-burn war of attrition.
The Approach:
Starve the plant of all sunlight, forcing it to exhaust its energy reserves and die.
How-To Guide:
Your goal is to cover the entire infested area, overlapping generously onto clear ground. Use a completely light-proof material. Good options include thick black builder's plastic or multiple, overlapping layers of thick cardboard. Standard weed mat is often not sufficient. Cover this light-blocking layer with a heavy (10-15cm) layer of mulch or soil to hold it down and ensure no light gets in. Weight the edges firmly with rocks or bricks, and leave this in place for a minimum of 6 to 12 months.
The Science Behind It:
This method blocks photosynthesis. Without light, the plant cannot create new energy. It will use up all stored energy in its stems and shallow roots trying to grow and find light, eventually starving to death.
3. Chemical Control (The Systemic Method)
For large-scale infestations or on difficult terrain, herbicides are often the most practical solution.
The Approach:
Use a systemic herbicide, combined with a penetrant, to overcome the leaf's waxy defense and kill the plant from the inside out.
How-To Guide:
A highly effective foliar spray application uses a triclopyr herbicide (600g/L active ingredient) at a rate of 6ml per litre of water. This must be combined with an organosilicone wetter (like Pulse Penetrant) at a rate of 2.5ml per litre. This wetter is critical. Spray to thoroughly wet all parts of the plant. This triclopyr-based mix is often "grass friendly" but be aware that overspray will kill other desirable broadleaf plants. Follow up quickly (within 2-3 months) before the plant recovers. You will likely need 2-3 treatments for total control.
The Science Behind It:
Tradescantia leaves have a waxy cuticle that repels water-based sprays. The organosilicone wetter is a "surfactant" that breaks this surface tension, allowing the herbicide to stick and be absorbed. The systemic poison is then translocated through the plant's vascular system, killing the stems, roots, and, most importantly, the nodes.
You can always have a crack with glyphosate but triclopyr herbicide seems to work better on a long term basis.
When using any herbicide or pesticide, PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and directions for the purchase, use, and storage of the product, are followed and adhered to. Do not use over water bodies or wetlands.
4. Containment & Suppression (The Long-Term Method)
This strategy is for when eradication is impossible (e.g., it's invading from a neighbor's) or as a follow-up to clearing.
The Approach:
Create physical and biological barriers to stop the plant's spread and outcompete it.
How-To Guide:
This strategy involves several tactics. Install deep (at least 15cm) solid garden edging at the boundary of the infestation to block the creeping stems. Exclude livestock at all times, as they can spread fragments. In an enclosed area, poultry (especially chickens) are excellent at controlling Tradescantia through constant scratching and eating. After clearing an area, densely plant vigorous, desirable groundcovers or shrubs to outcompete the weed for light and nutrients.
The Science Behind It:
This is a strategy of resource denial. Physical barriers block its path. Biological "grazing" constantly destroys new growth. Competitive planting creates shade and resource competition, creating a hostile environment for the soft new shoots.
5. "Zero-Fragment" Disposal (The Final, Critical Step)
This is not a removal method, but it is essential to the success of all other methods. Improper disposal will spread the plant and undo all your hard work.
The Approach:
Treat all Tradescantia material as highly invasive, viable plant matter.
How-To Guide:
You must treat all Tradescantia material as hazardous waste. It is critical to never put it in your home compost bin; it will survive, take over the bin, and be spread with your finished compost. Do not dump it in a public "green waste" pile or on the roadside. I can personally vouch it has ended up in my vege garden...
Instead, you must use one of two "kill" methods. The first is Solarization (Bagging): Place all plant material in a tough black plastic bag, seal it, and leave it in the full sun for several weeks to "cook" and kill the plant. The second is Drowning (Rotting): Submerge all plant material in a large bucket or bin of water, weigh it down, and leave it for 4 to 6 weeks until it has rotted. Only then can it be safely composted or sent to a refuse transfer station.
The Science Behind It:
Both methods (extreme heat from solarization or oxygen deprivation from drowning) completely destroy the cellular structure of the stem nodes, rendering them sterile and incapable of re-rooting.
How to Stop It Coming Back
To defeat Tradescantia, you must be more persistent than it is. All remaining stem fragments will resprout. Maintain a strict weed hygiene regime, cleaning boots and tools.
Do not replant the cleared site with desirable plants until you are certain it is clear, which may take several months of observation.