Wednesday, January 14, 2015

Killing Tradescantia fluminensis

Update Jan 2018 - Probably a better way to stamp out Tradescantia fluminensis than those listed below is to do exactly that, stamp on it. I noticed a bit of this plant I'd left on the floor was dead after being there for quite a short time compared with some of the more difficult methods listed  below. So I stood on some as an experiment taking care to crush all the nodes (lumps in stem) from which the roots and leaves emerge using the bare heel of my foot on a hard floor, they make a distinct "crunch" sound when neutralized. It is easy to spot any node you've missed after a few days as the plant is not wilting around it (I aim for the nodes since they are the reproductive part, but did a small experiment crushing only the stem and crushing only the nodes on two separate sections of plant, both took similar times to die, nodes a little quicker). After a week with sun exposure it looked like this:

You may be able to see it is dead aside from the growing tips which died the next day. I suspect the growing tips are harder to kill because they are smaller so harder to crush, shoes might have helped. 

This is a moderately time consuming and labor-intensive method but seems faster and in the end more efficient than any of those tried below. Perhaps it might seem a little more romantic and attractive a task if compared to pressing grapes. 

I'm surprise at how long it took for me to think of this, perhaps this was because it involves me doing most of the work rather than 'the easy way" finding some invented "slave" or "servant" such as poison or technology to do the work for me (the modernist utopia).

It might also be possible to kill or weaken the plants where they are growing by crushing the nodes with pliers or the like.

 Below are earlier experiments I probably won't be repeating now I've discovered stamping:
The following is the result of about 6 months of experimentation in organic, quick and simple ways of killing the incredibly resilient weed Tradescantia fluminensis (Wandering Willy, Wandering Jew) a serious pest here in Wellington, New Zealand. My aim was to find a way of killing the plant once it has been weeded/collected so that it can then be recycled back into the garden as compost or as mulch, this is not  an attempt to find an organic way of killing the plant on the ground where it grows.

The best method was found to be immersing the weed in a tub filled with a combination of worm castings from worm farms, the liquid produced from the worm farms, combined with up to 1/3 water (to make the solution go further). The Tradesantia is then weighed down so that it is totally submerged and left in the solution for 10 days, the solution being stirred every few days as it tends to settle. After 10 days the weed is laid out in the sun for 3 days, it is then completely dead in my experience.

1. Tradescantia fluminensis before treatment...the world's its oyster.

2. Tradescantia fluminensis placed in a large plastic tub filled with approx 1/3 worm castings, 1/3 liquid form worm farms 1/3 water stirred to become a thick dark mixture.  The less water the better.

3. Tradescantia fluminensis weighed down with brick so that it totally submerged.

4. Tradescantia submerged. So far this solution has not produced any notable smell, a consideration in urban areas . This was expected as worm farms are often kept indoors and usually produce no noticeable odour. 

5. Tradescantia left for at least 10 days, covered to protect from rain. Stirring from time to time was assumed to be necessary because solution settles becoming fairly clear near surface, I did not try not stirring it (you could experiment with shorter periods if in a hurry, I found after 5-7 days about 1% of plants survived, these could be put back in for another go since they like it so much).
6. Wandering Willy after removal from tub, the leaves are gone/dead but note the stems are still green. 

7. After 2-3 days in the sun the Tradescantia remains are completely dead. It seems to be necessary to keep the stems completely dry, in experiments some stems soaked in water for 10 minutes revived. In limited experiments drying indoors away from sunlight appears to be effective but takes much longer.

Use of Remains in Garden.
I have not yet experimented much with safety/appropriateness of using the resulting dry remains (presumably mainly carbon) directly in the garden. It is usually recommended worm castings should be added as a thin mulch in the garden (too much kills or weakens most plants) the same advice probably goes for this stuff , though I dried a reasonably thick layer of it out on top of other vegetation, it had no noticeable effect at all. I suppose a build-up of toxins over a long time might be possible if used over & over in same place, but it being washed away by rain seems just as likely.  

A compost heap is recommended in various places on the net as one of the few safe places to dispose of the liquid from worm farms. From this I'd infer putting the Tradescantia remains into the compost heap, especially in high rainfall areas, is probably fine.

I also tried putting a few remains into the worm farm, the worms seem much less enthusiastic about eating it than Tradescantia that had been through a blender, but after about a month it was gone, apparently largely with help from other minute beetle-like organisms also in the worm farm. Presumably the worms weren't crazy about eating it either because it was covered in their own waste or because it was so dry decomposition took place much more slowly (tiger worms eat rotting stuff). Soaking remains in water before putting it into the worm farm seemed to result in it being consumed/destroyed about twice as quickly, which might support either theory. More experimentation is needed here. 

Why does it work?

I don't know why it works. Supposedly worm castings are high in salts, this might explain why they dry up so quickly when left in the sun. Apparently worm waste is somewhat, but not very, high in nitrogen, reportedly nitrogen from human or animal urination on or near plants can sometimes kill them. 

Footnote: Some rejected or abandoned means of killing Wandering Willy.

Commercial Blender- effective but very noisy, fairly slow & tedious unless you can find a huge blender.

Chopping by hand with knife into very small pieces (less than 1 cm) effective but not as effective as blender, seem to re-sprout under certain unclear circumstances, probably access to water, very slow though can be calming

Placing in black plastic bags in Sun to "cook"  ugly, not practical if you have limited space, may take years, same if bags kept in shade or complete dark. Quickest when I put a bag on a corrugated iron roof that gets very hot in the sun. But still took a few months and there would be a limit to how many could go on a roof as a lot would stop it getting hot by shading it, also looks pretty bad.

Immersion in water. Effective but may take many months.  

Cooking in conventional oven. Only effective for very small quantities, large, practical quantities do not cook evenly.  Same would go for a specially made solar oven which a few people have thought of on the net but no one's tried it seems.

Immersion  in boiling water. As little as 10 seconds in boiling water kills Wandering Willy but this only works with small amounts held under with tongs, large amounts take much longer to return to boil. Protective clothing probably needed if repeatedly placing weed in boiling water over long period.

Immersion in human urine. More effective than worm castings and liquid mix, as little as 2 days soaking kills Wandering Jew, though 3-6 days better. Treated weeds also need to be kept away from water for several days once removed to dry out, otherwise they may recover. This experiment was small scale with small sections of weed, also source of urine was a meat eater, supposedly more toxic/high nitrogen. Urine smells and is likely to be unacceptable to neighbors and possibly officials, though this may not be true absolutely everywhere or in a more enlightened greener future. Unknown disease potential.   

Perhaps it would be possible to add 'hard to kill' weeds like this into some types of composting toilets or human waste recycling systems. 

Worm castings & worm liquid used separately. I found combing worm castings (with water) and worm farm liquid was considerably more effective than using either on it's own but experimentation was not especially extensive & could be explored more.

Food for humans & animals. A number of animals will reportedly eat Wandering Willy including chocks and Guinea Pigs. Aside from the fact that the nutritional content of this plant seems to be unknown, I did not try this method because of lack of space & aversion to slaughtering animals. Apparently one solitary source (The Encyclopedia of Edible Plants of North America(Couplan 1998)) states the young leaves can be eaten by humans when cooked. They are palatable in my experience, but that still leaves old stems and leaves, in addition to likely oversupply of edible parts.

Hot or Fast Compost Heaps, with very high ratio of carbon to nitrogen materials, turned daily or very frequently, have been recommended on the net for this plant & probably work (normal compost heaps are of course completely ineffective against this plant). I haven't attempted fast heaps as they seem like a fine art & it would be labour intensive turning large amounts of compost made from this prolific weed. Also Tradescantia is "green"/high in nitrogen so about 30 times as much "dry"/carbon materials would need to go with it to make the heap work, which would probably not be readily available. 

Finally a few interesting facts stumbled over: 

Spraying all of the above fluids onto Tradescantia using a commercial trigger sprayer had absolutely no effect, both on the ground where it was growing and indoors with cuttings, it's possible non-organic commercial spays are the only way of killing it where it's growing. 

I had to tell my dog not to lick the worm casting mix off the weeds placed in the sun, she really seemed to like it. I didn't notice her vomiting later on or becoming sick, perhaps worm farm waste could be a temporary emergency dog food if supplies are cut of in a disaster, dogs are well known for eating various kinds of feces, apparently without harm. I'm saying maybe this is a possibility, I have no expertise in this area & am not qualified to make any recommendations.

Also my pigeons started using the dried Tradescantia as straw to make nests once it had been dead for a week or two.  


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