“My bins are mostly cow manure fed. I’ve recently found a great (temporary) source for watermelon rinds. The worms love it, of course…so much so that I regularly move the population away from the rinds, back into the manure. I’ve lots of rinds coming… what will a higher rind to manure ratio do to the nutritional value of my worm castings? Will a mostly rind-fed bin produce decent castings or should I keep the amount of rinds minimal? I use my own castings and wish to continue producing hi-nutrient castings, but they really love the rinds!! Thanks!” ~ Ken
I’d have to say that, apart from manure, watermelon (and melons in general) has to be pretty well the favorite food of composting worms. For worms that are used to being fed manure (as yours are), I would imagine the watermelon would have even more appeal.
In all honesty, I wouldn’t worry too much about adding this material to your system – if anything, I would think that this additional material could be beneficial.
I would definitely recommend grinding it up and mixing it in with the manure however. This way you end up with a feed that possesses a much more uniform consistency – thus increasing the chances of your castings also having a nice uniform consistency!
As the name implies, watermelon consists almost entirely of…that’s right – WATER! 🙂
Worms love moisture, so this in itself should provide some value, especially during hot dry months.
The rest of the rind material will consist mainly of cellulose, so this (like straw and other cellulose rich wastes) should serve to help to balance the manure and add some valuable ‘structure’ (I’m assuming that when you say ‘lots’ you do mean LOTS!).
You mentioned a ‘mostly rind-fed bin’ – this sounds like an interesting opportunity for comparison. I suspect that castings produced from ‘mostly rinds’ would be high quality (again, I’d recommend grinding them up – and if you are not using much manure, you should also incorporate something absorbent as well) – but certainly different from those produced from strictly manure.
Remember, Ken – ‘different’ isn’t always a bad thing!
As we’ll start discussing next week, there is a lot more to worm castings than their nutrient values.
Anyway – hope this helps!