Get a borage patch going as well, and mulch that into the soil in the rest of the garden at the end of the growing season. It self-seeds like crazy and requires little maintenance other than cutting back if it gets too enthusiastic, bees can't get enough of it and they'll hit up your other plants at the same time, and that long taproot means that it'll pull up all sorts of nutrients that are too deep down for your other plants to get to.