I ordered an amaryllis from Plow & Hearth as a Christmas gift for my grandmother. It arrived today and is already in a planter with some moss covering it, but I don't want it to grow until after I give it as a gift - 3 weeks from now. They mentioned storing it in a cool dark place. If it's already planted, is it really OK to not water it for 3 weeks? I don't want it to be dead before it even grows, but I want it to still be new when I gift it. Thanks

A cool dark place should work, if it has not been watered and you keep it in a cool dark place it should stay in dormancy.

Ditto what Rj said. A cool and dry place should be just fine for it. If some green starts peeking through, it should still be fine for Christmas, just keep it in a low light area so it won't grow too fast.

There is plenty of moisture already in the bulb, it doesn't need wet growing media to start growing. So I guess dark and cool is your best bet. But if it has already started to grow, you may have to let it grow at this point. Otherwise you might end up with a leggy, pale scape. Do you have a photo of what it looks like today?