actually, if you plant them now you can get full size garlic bulbs next summer. It will overwinter in the stage of one-clove bulb and split next season.

I generally plant garlic in the fall around the outside of my 4'x8' raised beds. They are always the first green things in early spring. This year I had to move a couple of the garlic plants in order to fit some tomato plants in there. I transplanted them in early May. It's warmed up so fast this summer that I just harvested all the garlic this morning. Even though I was careful with the root system when I transplanted, the transplanted garlic were noticeably smaller. So don't discount the effect of transplanting on production. I'm in zone 6, so you may not have the same problems, but I wasn't as consistent at getting water to the plants early on as I could have been. Also, the shoots can be set back by frosts, so likely it was a combination of things that happened to slow the growth. But if your harvest date isn't for a couple of months, leave them be. At the very least you'll have fresh garlic greens and those are delicious on their own ;)

Here in Minnepolis, I always intend to mulch my garlic in the autumn, but whether I do or not top growth in the autumn is both common and seldom damaging. Currently I have some summer planted garlic that neither scaped nor dried off ( so I left most of it in place) and top growth in nearly all my autumn planted garlic of all varieties. Just about the only garlic that did not sprout were the bulbils. Japanese and Music lagged behind the rest, but a couple of varieties are nearly 10" high already. I refuse to worry about them. At least one of those varieties successfully maintained itself as a feral in NW Iowa (also zone 4) for nearly 30 years; so I expect to have some survivors at least in that one :). I planted in early and mid October this year much like in previous years, if maybe about a week early for some of it. I worry far more about bed drainage, especially trying to avoid having melt water puddle in the beds during warm spells and spring melt.

Tom - The OP appears to be in either Maine or New Hampshire. Pretty cold and snowy I imagine. I have a raised lettuce table outside that I could probably drill and plant in. It is about 16-18" deep. My concern it might freeze and thaw several times between now and next growing season. Thoughts? Covering the top of the soil with mulch might not do much on a raised lettuce table since the bottom of the soil will still be exposed to the elements. How much garlic are we talking about here? Do you have snow cover on your in ground beds yet? If you are not planting very much then I'd lean towards the drill planting as Zeedman suggests and then mulch heavily. If you have quite a lot to plant I'd probably put the bulbs in a paper bag and then into the crisper drawer of the fridge and plant as soon as possible in the spring. The fridge temps will vernalize the garlic and make it think it's been through a winter outside.