crusher dust as summer mulch?

Question

Crusher dust = cracker dust = bluestone tailings etc. It's a cheaper and coarser basaltic crushed stone compared to bagged rockdust products. I got some into the soil in winter. Now I've got summer crops already started but wanted to add some more crusher dust. Can I use it successfully as a mulch, an inch or two, before digging it in after summer veggies finish? If it works as a mulch as well then I'd rather avoid the cost and inconvenience of straw etc mulches for the vegies. The main thing I'm looking for in a mulch is moisture retention and wettability, which is something organic mulches aren't that great for in my climate (Melbourne Australia). Anyone used crusher dust as mulch?

Answer 1

I guess it depends what you're growing - crusher dust is highly alkaline, with a ph reading of around 9, so crops like onions will be fine - blueberries won't. So if what you're growing likes alkaline conditions, seems it's a good idea.