I doubt very much that garlic would penetrate that. Even just a couple of inches of un-chopped matted leaves can cause garlic to grow sideways under the mulch. The mulch should be loose, such as well chopped leaves, straw, hay, etc., and four inches is more than enough.

TomNJ

Hmmm, so maybe I should apply this layer everywhere except over my garlic, then next fall rotate my garlic to a treated area and cover the previous years garlic spot.

Thanks!

Wow, a lot of stuff in one area. Either a small garden or a lot of stuff to put on the garden. Just plant your garlic and put a two inch layer of mulched leaves. throw your other stuff in a compost bin.