You could just go here as there’s an excellent tool that goes into great detail as to the type of garden worms that you’re looking at but for most purposes there are a small number of common works that you’ll find this article will probably be enough. There’s been a huge amount of research over the years on earthworms and they are now being hailed as the ecological super heroes that they are. Charles Darwin’s spent 40 years studying them an exercise that culminated in the publication of his book ‘The Formation of Vegetable Mould through the Action of Worms, with Observations of their Habits’. A succinct title for a book that actually went on to sell faster in it’s first year than his slightly more famous book with over 6000 copies being purchased.
It’s no secret that worms are essential for the health of our soil and to make it into the ideal growing medium that we’re all looking for. This is one strong reason why we should all be adopting a no dig principal in out horticultural endeavours. Certainly using anything like a rotavator should be avoided unless there is absolutely no other way to achieve your desired results. I can’t think of any though. A lot of worms live and operate in the top few inches of the soil and really just want to be left to get on with what they do best and that is incorporating all of the organic matter that is added back into the ground.
There are about 16 species of worm that you’re likely to find in a regular UK garden and these are divided up into 3 categories depending on how and where the worm lives and what they eat.
These are the most common garden worms that you’re going to find in the UK and are also the largest. Their burrows are more or less permanent and are dug vertically down into the soil. They’re the ones that create the casts that you see on the surface of your lawn that are expelled from the burrow and gather in piles called middens around the entrance to it. As they burrow straight down they have the ability to gather a large variety of nutrients from various strata, usually feeding by dragging organic matter from the surface to eat much lower down. They’re recognised not just by their size but by their dark redo or brown heads and pale tails.
These garden worms in contrast to the Anecic ones tend to burrow horizontally through one strata looking for sustenance an nutrients. To some degree they can reuse their burrows but are know for their ability to move through the soil. If you’ve ever lifted a paving slab and seen the trails that are hidden underneath then you’ll have see the work done by these little guys. They’re smaller than the Anetic worms and are paler in complexion ranging from pinks, greys, greens and blues. The number of species in this group are too many to number in this post but there is an enormous amount of information to be found on the subject from the UK Earthworm Society.
If you know your latin then you’ll see that the name of these worms as the ones above denote a lot about their habitat. As with epigeal germination and the epicotyl in a seedling this relates to worms that live effectively above the ground. These are the ones that you’ll find in your compost heap munching away on all of the organic matter and turning it into the black gold that we’re after. They’re smaller in stature than other garden worms and have a stronger colouration as you’ll see when you find a writhing bundle in the middle of your compost heap. They’re fairly ubiquitous throughout the world but are not great burrowers hence the fact that they mostly reside in the upper most layers of the soil, among the leaf mould and of course in compost. Being an extremely adaptable worm is to the extreme benefit of us all as without these small creatures there would be little to convert the surface debris to topsoil, a process that is essential for so many ecosystems.