Knowing the water content of fruits and vegetables can be a handy tool in helping us keep a reasonable moisture percentage in our worm composting bins.
As you likely know, a good moisture level in a worm bin is about 70%, or enough to yield a single drop of water if the compost is squeezed very firmly in your hand.
Learn more about measuring the water content in your compost.
Use the handy reference numbers below to determine water content in fruits and vegetables
Water Content of Common Vegetables
Iceberg Lettuce: 96%
Green Cabbage: 93%
Red Cabbage: 92%
Sweet Peppers: 92%
Green Peas: 79%
White Potato: 79%
Water Content of Common Fruits
*Data from Bowes and Church’s Food Values, 1994
Why Do I Need to Know This Data?
One of the most common mistakes a new vermicomposter will make is to keep a worm bin that is way too wet.
This usually happens when people add food waste without additional bedding.
And as you can see, most fruit and vegetable waste are going to be much higher than the optimal 70% range which will keep your worm bins aerobic and your harvests easier and more worm-free.
So this means you need frequent additions of drier, carbon-rich bedding to soak up all of that excess moisture that you’re introducing to your bins. This will help control mites and fruit flies as well.
While I don’t suggest that you try to calculate your food waste and bedding moisture levels down to the “gnat’s rear-end” levels, I think it’s incredibly helpful to know what’s actually going into your worm bin.
4 thoughts on “Water Content of Fruits and Vegetables: Vermicomposting 101”
I think one of the reasons I’ve not had a problem with this, is because I freeze all fruits & veggies before feeding. When I thaw them out, I put them in a big old sieve/screen and press excess water out of them, before adding them to the worm bin. But, I always add bedding if the layer of bedding on top of the castings, is getting thin. I like a couple inches of slightly damp bedding, over the whole top surface of the bin. So far, this has worked well for me.
Thanks for the info Steve, I was surprised to see some of the results that they had that high of a concentration of water in them.
Right now there are more pumpkins out there that you could imagine.
Good information Steve.
Since I use a blender on almost all of my food I have had a problem with too wet of bags. Because of that I have been mixing all of my blended food with either the aged horse manure or shredded paper. This way I bind the excess liquid in a more stable form.
If I feel it’s still staying a bit wet I just leave the zippers open for the day. (They are in a screened in porch so they are out of the weather and possible predators.) I zip them up for the nights. (No escapees for me!)