Weymouth, Mass. — Last year some University of Georgia scientists took a close look at the earthworm, or rather its castings, to see if, indeed, this material was anything like the soil-fertilizing wonder that some folks claimed it to be.
Not that they doubted the value of the castings, they simply wanted to do some comparative tests with standard fertilizer-enriched potting soils. The result; An A-plus for the castings.
After getting excellent growth with tomatoes and coleus grown in pure worm castings (and chemical analysis of the plants revealed no nutrient deficiency), several plants species were grown in castings in head-to-head competition with plants grown in potting soil. All but spinach grew more vigorously in the castings than in the potting soil.
These were the dry weights of crops grown in earthworm castings compared with potting soil: spinach 2.6 grams in castings, 3.7 in potting soil; tomato 4.7 to 4.1; petunia 3.0 to 2.6; lettuce 0.7 to 0.1; marigold 3.1 to 1.8; and eggplant 0 .3 to 0.1
The importance of these tests to the home gardener is not so much that castings are superior to potting soil, but that they prove that worm castings are extremely valuable. The need then is to encourage the worm population within our soils and perhaps make use of the waste-consuming little creatures to produce our own high-quality potting soils indoors all year long, using the food and other waste generated in the kitchen.
Out in the garden, the simplest method of feeding these worms is to spread a mulch of shredded organic materials (I use leaves principally but also some straw and weeds). The worms feed on it all year round except during the winter months when the cold penetrates the mulch to freeze the soil.
Indoors, however, your little fertilizer factory will operate unceasingly, whatever the weather outdoors. Put another way, the worms will take the place of a garbage-disposal unit on the sink and return you a dividend at the same time.
Any cellar or garage where the temperatures do not plunge much below 50 degrees F. is suitable.
While the worms will survive any temperature above freezing, they become increasingly sluggish when soil temperatures fall into the low 40s. Simply, chilly worms won't process your garbage fast enough. Worms also slow down when it gets too hot -- 80 degrees F. and up. Extremely hot temperatures are not likely to be your problem unless your worm pit is a nicely camouflaged box alongside the kitchen stove.
Some apartment dwellers have kept a worm pit in a spare cupboard. I've also heard of another who kept one under an upturned box that substituted for a seat at the kitchen table.
Start small, even if it means not all your waste is processed at first. With experience you will become expert at running a worm pit and learning how much waste they will process in a week. Remember, however, that the processing will increase dramatically as the worm population builds up. Theoretically, one worm can turn into 193 worms in a year, given good living conditions and ample food.
Good living conditions are provided by the moist bedding in which the worms live as well as the good food which you give them -- vegetable peelings, food scraps, etc.
You can easily build a worm pit out of lumber, or even concrete blocks if you wish. Any size box will do as long as it has sides about 16 inches deep. Bushel baskets are good, but so are the boxes which are used to bring fruit and vegetables to market. Galvanized wash tubs make excellent worm pits.So do oil drums which have been cut in half. Bang a few holes in the bottom to allow for drainage.
Some people recommend placing an inch or so of sandy garden soil in the bottom of the box and then filling it to the top with bedding which can be made from a 50-50 mix of manure and peat moss. In place of peat you can substitute shredded leaves and straw and then add some shredded or ground paper. You can also add compost when it is partly decomposed and in the crumbly stage.
The bedding itself is food for the worms. Additional high-quality food comes from the kitchen waste.
It is important to keep the bedding comfortably moist (peat moss should be soaked overnight before being included in the bedding) and it should be placed in the bins or pits several days before the worms are introduced. This is to allow any heating up (rapid composting) of the bedding to run its course before the worms are added.
In feeding the worms, add the kitchen scraps to a trench in the bedding and cover it up. This way the worms will be drawn to the garbage and feed on it at will. Food wastes tend to be acidic. And while earthworms can consume acidic materials, they cannot live in them for long periods. Thus, they must be able to escape from the acidic environment whenever they wish. For this reason, then , never mix the food wastes deeply in the bedding.
By the time the waste begins to look black and soil-like it will be ready to use on the garden. Then you will have to start all over again.
To get the right worms for your pit, go to your existing compost heap in the yard or to a pile of manure which will attract the right type of worm which is slightly pink in color. Or look for ads in a local newspaper or in the gardening magazines which offer worms for sale.
Avoid the larger earthworm (he tends to be plain gray all over) and the big night crawler. These are soil eaters rather than concentrated garbage eaters and will not do well in a worm pit.