How to build a Dendrobaena worm farm

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The Dendrobaena veneta, also called European night-crawler, is a large, tough and very active type of worm. It wriggles around incessantly when exposed to light and is most popular as bait for fishing.

The night-crawlers can eat up to half its body weight in vegetable matter every day, making it valuable in home composting situations. Put together a worm farm of your own using a starting population of night-crawlers, to both recycle kitchen and garden scraps and produce rich, crumbly compost for the garden.

Prepare a shallow plastic container for your worm bin. Night-crawlers are surface feeders and must be able to reach the soil surface easily. Use a bin that measures 60 to 90 cm (2 to 3 feet) long and 60 to 90 cm (2 to 3 feet) wide, with a depth of 2.5 to 5 cm (1 to 2 inches).

Fill the box halfway with garden soil to provide grit and nutrition for the night-crawlers, to aid in their digestion. Lay 1.25 cm (1/2 inch) of shredded paper or sawdust on top of the soil to retain moisture for the worms, who need a moist environment to breathe. Mix these two together.

Water the bedding until it's as wet as a well-wrung sponge, but not soupy. Worms will drown in swampy bedding, but will die if they dry out. Always maintain this level of moisture in the bin.

Set 0.5 kg of night-crawlers on the bedding and allow them to dig themselves in. Put the worm farm in a spot where it gets indirect light, air circulation and temperatures between 12 and 21 degrees Celsius. Worms will die if they are under direct, constant sunlight, rain or freezing temperatures.

Fold kitchen scraps into the bedding at least once a week, and mix the bedding around during the feeding to aerate the soil. Since night-crawlers prefer vegetable matter, focus on old fruit, vegetables and garden scraps. Supplement these with more shredded paper, coffee grounds, egg shells and bread products. Water the farm every time you add food.

Empty the bin and clean it every three months. Dump the bedding out, collect the worms and put them to the side. Pull out the largest worms for sale or for your garden and throw the used bedding into the garden as compost. Add new soil and shredded paper, and replace the worms you're keeping in the bin.