Best tool for digging in/turning over green manure in clay soil?

What tool would people recommend for digging in my green manure (mostly phacelia and poached egg plant and whatever annuals self-sowed this year) for my flower bed come spring? I have clay soil and a bad back. I was thinking a draw hoe or chillington fork hoe.   I don't want to dig it up now because it will turn into a quagmire that my dog will run through. I don't want to use a power tool because I will be working around some perennials.