African nightcrawlers

African nightcrawlers are a tropical species and behave like one. Given warmth they are the fastest castings producers of the common composting worms, eating more than twice what red wigglers will, breeding rapidly and growing to the size of a pencil. Take the warmth away and they fail quickly. Everything about keeping them comes back to temperature.

Identifying them

Adults are long, six to eight inches, with a greyish purple to brown body and a distinctive iridescent sheen. They are noticeably more muscular than European nightcrawlers and move fast when exposed to light. Hatchlings are tiny and pale and can be mistaken for other species until they grow. What type of worm? gives an overview of how the common composting species differ.

Keeping them

Keep the bed above 70 °F and they will reward you; let it drop toward 60 °F and they will try to leave the bin, and below that they die. In most of the United States that means indoors, a heated space, or a summer-only outdoor bed. They dislike being disturbed and dislike light more than other species, so a lid and a hands-off approach help. They are heavy feeders and heavy drinkers; keep moisture up. The farm’s notes on running worms through a hot summer and on growing worms, worms, worms apply directly.

Castings

If worm castings are the goal and you can supply the heat, Africans are hard to beat. Their castings are fine-textured and plentiful. Worm castings explains what makes castings different from ordinary compost and how to use them.

Africans on this farm

Worms Etc offered African nightcrawlers in its later years alongside Europeans, mainly for customers in the Deep South and for anglers after a large bait worm. For a first bin, or anywhere the bin may get cold, start with red wigglers or Europeans instead.