After 20 years of gardening, I've tried it all! Square foot gardening, no till, double dig, organic methods, commercial fertilizers, and back to eden mulching . Because I garden in raised beds, I have a big problem with moisture retention. Raised beds dry out so much faster than gardening in the ground. Back to Eden recommends mulching deep to provide an environment conducive to earth worms, to retain water, weed suppression, and to provide compost materials as the straw mulch breaks down. There are pros and cons to this. The biggest con - slugs on strawberries ! But it does help with watering - a lot. And for that, it's worth reworking. I think I found a solution that is the best of both worlds. Cocoa Shell Mulch Cocoa shell mulch is a lightweight mulch so it doesn't provide a deep bedding environment conducive to slugs. It also heats up in the sun (due to it's dark color) and that is less exciting for slugs, but great for heat loving plants like tomatoes.