Definitely looks like you have some beds to work with already! Where are you located? I'm in Fort Walton Beach and in my backyard this year I've built some beds using Landscape Timbers. I built them about 20" high and layered them with small sticks and some dead vines I cleaned up off a fence line and then put a layer of leaves before putting in ground garden soil on top. In time the layers below will decay and feed the plants growing on top. I'll post some pics once I get them off my phone!