Yes, you do plant the individual cloves. If its only been a few days try digging round bulb and see if its rooted yet. The roots if started should be small so just take care not to damage roots.

Warthog, whos dogs dig up cloves all the time and they still manage to produce a bulb.

Carefully dig up the bulb and separate it into cloves. Plant the cloves poiny side up about 2" deep, 6" apart. And start thinking about this fall. In zone 5 you should plant in fall. It is tons of fun, you get to garden in the fall, and then you barely have to do anything until harvest time. (but I still check up on my babies daily) I would recommend hardnecks mainly for zone 5; I am zone 4 and of the one softneck variety I planted only 3 cloves of about 20 survived. By contrast, only 3-4 cloves out of over 200 hardnecks haven't sprouted. Check out some online sources and choose a couple for next season.

Alternatively, you can leave the whole clump to grow as green garlic----scallions made of garlic instead of onions.

As the summer progresses, carefully uncover the bulb, break off the stalks you want, then recover the bulb. Leave the best of them in the ground, and, next spring, it will be the same as if you'd fall-planted a clove. Next summer you'll get a full head from the one you left behind.

Ok, this is my first attempt at growing garlic and I did the same thing. :(

I planted them 3 weeks ago, though, and they've sent up little green shoots. Is it too late to separate the cloves and try again?

When I plant garlic its usually by the end of the summer for the next years crop. Thats whats going on right now. All my garlic is getting foot long greens and when they start to send up scapes, they will be left only a short time longer when the greens die out. Digging them up now and seperating the cloves may be OK, but don't expect any big garlic bulbs this year, unless they grow very well through summer in z6 without bolting first.

Cleveland, if you planted more than one head, maybe you want to dig up and separate some, and leave the rest as is? I am a firm believer of eggs and baskets.