Worm farms are an ideal and fun way to turn kitchen and garden waste into useful compost and fertiliser. Worms used for composting are not common garden earthworms, they are a much more voracious variety but require different conditions to garden worms. The two are not interchangeable, composting worms will not survive in most gardens and garden worms will not produce an adequate amount of compost in a worm farm.
Keeping a worm farm healthy and productive is not difficult and no special equipment is required, but some basic principles should be adhered to. Worms require a most, rich soil to thrive and, for best results, should be fed regularly. A little and often is best. Worms eat a wide variety of organic matter; in fact, almost anything that was once living is fair game. There are just a few things to bear in mind.
Keep the worms out of full sun during the summer months. Our farms are well insulated but are still best kept in the shade during extreme weather.
Worms will eat shredded newspaper, straw or cotton shirts and towels. However, these are quite low in nutrition and should not be the sole ingredient in the diet.
Avoid too much acid or fatty waste. Citrus peel, onions and meat should only be used when mixed with lots of other scraps and waste.
Bury food scraps just below the surface or mix the scraps with soil before adding to the farm. This helps prevent flies and other pests building up. Also feeding on alternative halves of the farm is helpful.
Chopped garden waste can be used. Anything from lawn clippings to vegetables. Ideally, vegetables should be put through a food processor and chopped finely before use. Very large chunks of vegetable matter may rot and attract pests before the worms have had chance to eat it.
A hand full of grain or rolled oats will restore vitality to the farm if the diet has been poor.
Table scraps and, to a lesser extent, animal manures can create acidity. It is a good idea to check pH now and again, particularly if the farm is not looking very active. Soil testing kits are available at all garden supplies. Acid soil can be compensated for with a light dusting of garden lime or wood ash, careful not to overdo it. Before adding lime, leave the lid off for 15 minutes or until the worms have burrowed deep into the soil. Sprinkle on the lime and rake it into the top layer with your fingers. Never use Builder’s Lime. Crushed eggshells can also be beneficial in raising pH.
White worms or Pot worms will be present in your worm farm. They are not harmful to the red worms (as far as I can tell) and they help with the composting. However, White worms thrive in different conditions to red worms and an overabundance could indicate acidic soil and too much moisture. Both conditions easily treatable. To remove some of the white worms, soak some bread in milk and leave it in the farm for a day or so. The white worms will be attracted to this and it can be removed and thrown on the garden.
Egg shells add calcium to the castings. Calcium, from sources such as eggshells, is not readily available to plants until it has been eaten by worms. Evolution is your friend here. The crushed shells also provide grit which helps with digestion. Adding builder’s sand can also be beneficial.
Worms can eat their own weight in food per day. You will soon get to know if you are feeding your worms adequately. The amount to feed them depends on the quality of the food, the number of worms and the air temperature. In ideal conditions the worms will be very active, breed rapidly and consume a lot of food. Dig out a handful of soil to check on the activity and conditions. There should be plenty of active worms scurrying away from the light. The soil should be moist but not wet. Too much food, especially uncovered, can attract unwanted pests and smells.
Allow for good drainage and aeration. There should be adequate bedding material at the bottom of each tray. This can be made up of coarse matter such as small twigs, straw and leaf litter.
Harvesting the castings
When a box is almost full, add soil to the level of the top. Put the next box (level 2) directly on top of the bottom box and sprinkle soil and sand into the drainage holes to form contact with the soil from the bottom box. Form some bedding from small twigs and straw and start adding food as before. The worms should start to migrate almost immediately but could take a couple of weeks to complete the migration as there will still be plenty of food in the bottom box. The bottom box can be removed and the castings are ready for use for compost. They can be added to potting mix for indoor plants or sprinkled round seedlings in the garden.
If you are too impatient to wait or wish to rescue every last worm, then there is another course of action. Tip the castings out onto concrete or newspaper in full sun. Mound the castings into a pyramid and allow the outer surface to dry out. Scrape away the dry castings and allow to dry again. The worms will form a tight ball as far away from the light as possible, at the bottom of the heap. The worms can be rescued and reintroduced to the farm. They will be forever grateful for their salvation. The castings are now ready for compost.
Liquid Manure – Worm Tea
The Worm Tea is extracted from the tap at the bottom of the farm. This should be emptied regularly and is the most prolific part of the farm. Mixed with water at a ratio of 8 or 10 to 1 and applied with a watering can, it is an excellent fertiliser and plant tonic. Many worm farmers prefer not to use the tap and let the leachate drip straight into a bucket, this helps to alleviate the potential problem of anaerobic pathogens. Either way, using the juice regularly and not allowing a build up is preferable. As far as I can tell, anaerobic pathogens are a problem for a few people on the Internet who may or may not be gardeners.