“Hi there, Could you tell me where Red Worms (Eisenia fetida) originate from? If they got into my garden soil when I was adding some vermicompst, would they cause any harm to my garden? Would they survive? Thank you” ~ Ashley, Johannesburg, South Africa
According to Edwards and Bohlen (1996), Red Worms (Eisenia fetida), along with numerous other common worms from the family Lumbricidae, have spread from Northern and Western Europe to many parts of the world within the last few hundred years – primarily thanks to the activities of humans.
The Red Worm in particular has become an extremely popular worm throughout the world due to its talents for processing organic wastes, thus helping it to expand its range even further than some of its lumbricid relatives.
That being said, the Red Worm is specialized for a habitat that is very rich in organic matter, such as compost and manure heaps. They can survive in soil if sufficient organic material is present, but it is rather unlikely that they will outcompete the native soil worms which are highly adapted for that given habitat.
If you are simply adding vermicompost that happens to have some cocoons in it, rather than actually trying to raise these worms in your garden, then you have even less the worry about.
While some of them may indeed hatch, again it is very unlikely that they will become well-established unless you happen to have lots of organic waste materials in your soil.