New Zealand Flatworms feed on our earthworms reducing the condition of the soil. They were indeed a worry to me when I first discovered them in my garden over 10 years ago. Gardening magazines at the time showed pictures of devastated gardens with plants dying or dead as a result of the absense of earthworms where flatworms were reported.
The Flatworm doesn’t destroy the plant only the earthworm which enriches the condition of the soil so the plant grows well. All is not lost if you have just discovered the flatworm in your garden – perhaps under the base of a pot as I did. Gardens can survive with, and after, flatworms as I myself can confirm. However if you have flatworms you must take extra care to prevent them spreading further. To see a New Zealand Flatworm and its egg click here .
BBC Gardeners’ World Magazine, at the time of my discovery of flatworms, had just issued an article on the New Zealand Flatworm with some lovely (not) colour photographs. How fortunate that was for me. It had a brief description of how it could change its shape making itself so thin that even if you tied a knot in a bag there was still a chance it could escape – this was very accurate as I have witnessed! The article also showed a map of the UK with locations where they had, at that time, been reported. It also asked for new sightings to be reported so data could be compiled and as they were only starting to appear in my area I felt a sense of obligation to report mine.
The Scottish Crop Research Institute, in Invergowrie, was where I reported my sighting. I phoned the contact given, Dr Brian Boag, who was conducting research on them at the time. I can clearly remember asking if I was the first to report from my town and feeling the horror that – I was! He told me how to trap and destroy them and also to look out for eggs (like small oval blackcurrants) and destroy them too. I kept a jar, with screw top lid, at my back door with very salty water in it – behind a plant pot so I didn’t need to look at it!
Carrier bags filled with soil, were the traps I laid, on bare pieces of soil where possible. These weren’t the most attractive addition to my garden as you can imagine! It did work though. I found the carrier bags needed to be of good quality to last out in the rain etc. I do remember going into my nearest Laura Ashley store asking if I could buy some of their dark green carrier bags (a bit more camouflaged in the garden when turned inside out) but I couldn’t persuade them at all!
Coiled-up flatworms could be found under the carrier bags during my daily morning check – I could collect up to five. It did seem if I was lucky in one area I could put two bags there and be twice as lucky! The flatworm did seem to return to the same area once it was found there. I did also notice that the soil was warm as well as damp which must have been ideal conditions for the flatworm when I was so successful with my traps. I can recall gingering lifting them up with my garden trowel and trying to shake them off into my jar. It’s really a good job you can’t see my face squirming at the thought of it. Within two days of being in the jar they turned milky-ish as their own poisonous enzyme, that destroyed the earthworm, destroyed it. I am now absolutely cringing at the thought of them decomposing now. It’s coming back to me now – the awful smell inside the jar when I opened it.
I took the brave step of telling my neighbours – not a popular move at the time! The reality was that although I had identified Flatworms I hadn’t necessarily been the one who had brought them to my garden. Knowledge is power, so I thought, the more people that were aware of the problem the higher the chance of stopping them spread. I also took the step of rinsing the roots clean on any plants that I gave away to friends and family. I did my best to stop Flatworms spreading but like a needle in a haystack I had absolutely no chance of trapping them all.
Earthworms are scarce, in my garden, and if I ever find one when digging I feel delighted to see them again – hey I know that sounds sad but it is true. Pre-flatworms I would be uninterested in the seemingly insignificant earthworm – but gosh does do it not do an important job with our soil! My soil only gets aerated when I dig or hoe it and if I don’t a type of moss will grow on the surface of my soil. So, a little work is required to keep the New Zealand Flatworm at bay and the soil in order – but looking round the garden at my plants it is undoubtedly worth it.
For further information on the New Zealand Flatworm go to: