I don't think its good to put on your garden. Just bag it up and send it to me and I will dispose of it for you. Just kidding, I am not sure how much to put on either but I just could not help myself.

If you were to Google "bat guano application rate" you would get links to several companies selling bat guano fertilizers, with discussions of application rates on their pages. It is pretty rich - like a 12-12-2 fertilizer - so you are going to add it at a rate more like sprinkling fertilizer granules around plants than like shoveling compost.

Wear fitting dust masks when you collect it.

If you really want to know what it contains, take a sample to your local soil-test people and have them test it. I doubt that it would cost any more than a basic soil sample (maybe $10), but ask. And ask them how much to use per 100 sq ft, then you can figure anything up or down from that.

And may I say I'm jealous? Guano has been a valuable commodity for centuries.

Sue

I'd compost it before using. As I understand it, bat guano that's sold are the droppinings of bats that have been processed by various beetles which make it benign. Be careful of the dust as you try to collect it.

tj

Here is a link that might be useful: Bat-ter up