Raising nightcrawlers is similar to raising red wigglers but there are some important differences.
There are different types of Nightcrawlers: European Nightcrawlers (Eisenia hortensis) and African Nightcrawlers (Eudrilus Eugenae) otherwise known as the Giant Worm. African Nightcrawlers can grow up to 15 cm long. There are other types of nightcrawlers as well but for now we will stick with these two.
The reason these worms are called nightcrawlers and that is that you would typically find them on the surface of your garden at night. The find food on the surface of the ground and then drag it down into their burrows. They are fabulous for mixing and aerating the soil.
Nightcrawlers are much deeper level worms than red wigglers and do not take as well to a worm farm. The conditions need to be kept ideal otherwise the worms will just move out. If the farm is too wet, acidic, anaerobic, rotting or otherwise not suitable they can evacuate a farm overnight. A pile of worms on the floor in the morning is not a good sight especially if they have managed to spread out over a large area.
Raising african nightcrawlers also requires a warm environment, they do not like cold. Try and keep the farm between 10-25 deg C. The ideal temperature for maximum reproduction is 15-20 deg C.
Your farm should also have a neutral ph. Frequently adding agricultural lime to the farm will balance the ph. You should buy a soil test kit at your local nursery or use some litmus paper to test if the farm is acidic. You do not need an accurate ph reading, just an indication will do.
African nightcrawlers do better with more soil in the bedding material than red wigglers. We have found that mixing 50% soil with pre composted cattle manure makes an ideal material when raising nightcrawlers.
If you have a small farm use wet shredded paper, coir, peat, or cardboard and mix this with 50% soil from your garden. Place the nightcrawlers in the farm and cover them with more bedding material. When you feed the nightcrawlers lift the bedding, put the food in and cover.
Nightcrawlers will burrow down into the farm and create a tunnel system. Try not to disturb the worms by digging around in the bin. In the wild they can dig down almost two meters!
Feeding nightcrawlers is easy and is pretty much the same as feeding red wigglers. The same warnings apply: do not overfeed, feed in one spot so that the worms have somewhere to go if the food goes off, keep the farm moist, do not feed acidic foods.
A good way to tell if the farm needs more food is when the top of the farm bed is covered with fine particles that look like soil. This is a good indication that the worms have eaten all the food and need more.
Nightcrawlers are very active and will attack the food you put into a farm, often swarming the food - it can be quite a sight.
Nightcrawlers need the same care as red wigglers but with more attention to keeping the farm warm. Nightcrawlers will not retreat from cold like other worms and will freeze to death very quickly. Read Worm Farm Care to get an idea of what conditions your worms need to survive and flourishl.