What Do Worms Eat
I am constantly asked what worms can eat or what to feed them. In short there are variety of items to feed them however before I get into more detail, allow me to give a short list of what and what not to feed them.
What Worms Can Eat:
- Purina Worm Chow
- Fruit and Vegetable scraps.
- Starchy food waste, i.e. bread, potatoes
- Heated Animal Manures, i.e. chicken, cow, horse, rabbit
- Shredded newspaper and cardboard.
- Coffee or Tea grounds (not the tea bag itself)
- Ground Dolomite Lime or Eggshells
Do Not Feed List:
- Dairy or dairy by products
- Meat or meat by products
- Human or pet waste, i.e. cats, dogs
- Oily or Greasy food wastes
- Non-Biodegradable materials
Before I go on, allow me to elaborate on the good list of what worms eat a little. When feeding anything with the exception of Purina Worm Chow, use in moderation. Secondly even though worms will eat fruit and vegetable scraps, you will want to minimize the amount of citric acid found in produce such as grapefruits, oranges, tomatoes… as this will make the worm bin go acidic rather quickly. Also remember that adding fresh fruit and vegetable scraps will increase the water moisture level of your worm bin. This especially holds true for produce such as melons, cucumbers, pumpkins…
Now while others will say worms cannot eat solid food waste they can to a degree. The below pictures will illustrate this with the first one displaying some shredded rabbit manure placed in a worm bin tray containing 500 African nightcrawlers and the second showing the results just 12 hours later. Since worms do not have teeth they cannot bit off chunks of food but can digest whatever will fit in their mouths.
While spent tea leaves are fine in moderation, as most composters realize the tea bag itself in most cases does not break down. This is due to the fact that they contain polyester plastic netting woven in to insure the integrity of the tea bag and preventing unwanted tears in the bags when brewing your tea. At the same time, tea and coffee grounds are acidic. While I found controversy on this issue online I decided to run my own tests and found using a variety of different spent coffee grounds the pH to run from 4.5 to 5.3 making them quite acidic.
Manures can be fed to worms however a few words of caution here. Most all manures need to be heated prior to feeding your worms. Heating to 145 degrees Fahrenheit is a good way to help eliminate unwanted seeds from growing in your worm castings especially when using horse manure which is known to plague gardeners with unwanted seeds from growing.
On the other hand rabbit manure is called cold manure. In one aspect it is true, however don’t allow this to fool you as the picture below illustrates a pile sitting outside that is approximately a foot tall heating up to about 115 degrees within one week. The outside temperatures have ranged from about 30 to 59 degrees over the same time period and sits in the shade. At the same time, rabbit manure can be fed directly to the worms if placed in thin layers, hence not heating up as much of approximately 2-3 inches at a time.
One item to be extremely careful of when using any manure is the salt content. The urine is almost always part of the mix which can contain high levels of salt which in turn can be detrimental to your worms. Even bagged material which is listed as composted manure can contain high levels of salt. In a worm bin, salt levels will increase with the addition of any materials containing salt hence building the percentage levels of salt throughout.
Starchy food waste, such as potatoes, bread and past (without sauce…) can create havoc in a worm bin if too much is used. In fact I would recommend for anyone just getting started avoiding these products for a while until they are accustomed to worm composting and then feed in very small amounts.
Ground eggshells will work for many as a way to help neutralize acidic conditions; we use a pulverized, unbleached Dolomite lime for two reasons. From tests that have been performed, eggshells take longer to raise pH levels however the effects last longer while the Dolomite lime is faster acting. Secondly, Dolomite lime contains higher concentrations of magnesium, something all living organisms require to break down calcium.
When it comes to shredded newspaper and cardboard there are a few things to keep in mind.
First, one can use color newspaper such as the comics however keep away from the glossy colored print pages. As for cardboard, the same pretty much holds true. Keep away from glossy or tear the gloss layer off prior to adding to your worm bin.
As for printer paper, most of it is bleached and from our prior testing we found the worms avoid areas of the worm bin containing these types of paper since the bleach leaches into the bedding materials.
Lastly one needs to know what specific worms like to eat when it comes to these types of shredded materials. Take for instance red wigglers which like both materials compared to African nightcrawlers which do not perform well on shredded cardboard however will devour shredded newspaper faster than any other worm I have raised!