Culturing White Worms
by Humphry Axelbearing

The worms crawl in, the worms crawl out, the worms play pinochle in my stout!  Despite the disturbing imagery of that variation on a popular nursery rhyme, and their reputation for being slimy lowlifes (perhaps not so different from the reps of may killie-keepers)… worms have historically made a major contribution to fish keeping and breeding.  White worms have been cultivated by tropical fish enthusiasts for decades, and many award winning fish breeders will attribute part of their success to liberal feeding with these nutritious little annelids.  Another factor that contributes to the popularity of the lowly white worm, is that they are easy to propagate - if you take into consideration their basic needs.

Culturing white worms:

There are 3 things that are essential to the cultivation of white worms, temperature, temperature, and temperature.  In case that was to subtle, the most common problem encountered in keeping white worms alive is, in a word, temperature.  White worms are most productive at a temperature range of  55 - 65?F.  When the temp gets to 70?F they stop reproducing, and above that they begin to die.  So the best bet is to keep white worms on the floor in a cool corner of the basement - or if you do not have a basement you can keep them in an old refrigerator that is rigged to maintain about 55?F.   [The upside of this approach is that 55?F is the perfect storage and serving temperature for beer - especially porters & stouts!] If you can't provide a temp below 70 year round, you are likely to become very frustrated trying to keep white worms!  After meeting the temperature requirement, there are a few other less stringent considerations to consider regarding culture containers, media, feeding and harvesting. 

Choosing a worm culture container:

Almost any container will work - the traditional white worm farm is a 12 by 12" wooden box.  Alternatives include styro's, plastic shoe/sweater boxes, or an old aquarium.  Wooden boxes have the advantage of absorbing excess water, which in turn evaporates off the outer surface of the box.  This keeps the box a bit cooler than the surrounding air.  It also wicks water out of the soil, so you have to keep adding water to keep the soil from drying out.  Plastic boxes require that you be more careful about adding water, since they stay wet for a long time after watering. Whatever you choose, include a loose fitting cover or punch air holes in a tight fitting lid.  [note: a bit of foam inserted into the holes that vent the worm box will prevent the small black flies (midges, gnats?) from colonizing your worm farm, and help you reduce the SAF (spousal annoyance factor).]

Culture media:

A three inch deep layer of a 50/50 mix of potting soil (or topsoil, garden soil, etc) with peat moss is ideal for propagating white worms. The soil mixture should be kept wet enough to form a ball when squeezed, but dry enough that you cannot actually squeeze drops of water from the soil.  I sterilize the peat in boiling water, and the soil by baking it in the oven (300?F for an hour) before use.  This may seem excessive, but soils often contain insect pests (like the little black gnats), even if the bag says "sterile potting soil".  Sterile soil was probably sterile once upon a time, but there are usually holes in the bag through which the invaders can enter.

Foods and feeding:

White worms will eat almost any from of decaying organic matter.  I have heard of people feeding lettuce, cabbage, potatoes, baby cereal, cornmeal, oatmeal, bread (plain or dipped in water/milk), cheerios, rice crispies, dog/cat food, and the list goes on and on…  I performed a series of experiments where I offered a variety of foods and let the worms choose - the bottom line was that they preferred cat food (Purina cat chow) over all other things I offered.  So for the past year I have fed them cat food almost exclusively, and with very good results.  I dig a shallow (1" deep) pit in the soil, and add cat food.  Then I sprinkle it with water.   I feed an amount the worms can completely consume within 3 days, and I feed them only when there is no trace of old food leftover.  If the food is not consumed fast enough it tends to get moldy.  If this happens you can either remove it, or bury it in the dirt an forget about it. 


The worms will come to the food, and form dense masses around the edges, and sometimes completely cover the food source.  So the day after feeding I simply pick off clumps of worms with a pair of forceps (or my fingers) and drop them into a cup of water.  I usually rinse them a couple times in order to remove any residual dirt or cat food from the mass of worms, and then feed them to the fish with an eyedropper.  White worms can survive underwater for several hours, but will eventually drown, so the amounts fed should be adjusted accordingly.

Long term maintenance:

In addition to the normal routine of feeding, watering and harvesting, white worms require very little maintenance.  I would suggest stirring up the soil every 2-3 months for a couple reasons.  First it helps to keep the soil loose, and second the worm droppings will tend to accumulate around the feeding areas, and will eventually acidify the soil (not to mention the smell). Another suggestion is to replace half the soil on an annual basis, the discarded soil is very rich and makes great potting soil.  If you want to expand your worm farming operation, the easiest way is by splitting a thriving culture in half and adding new soil to both halves.

As always… keep you mops wet and your martini's dry!
The Hump