Nick the stem with a sharp knife or fingernail - you're looking for green phloem tissue immediately under the periderm (bark). If you find it and the bark is still succulent/spongy, there is still hope. I've had plants, like a root cutting of a willow-leaf ficus, that showed no signs of life (other than the fingernail test) for more than a full year after planting, only to have the tree suddenly explode with growth. I currently have an established camellia cutting a friend sent in spring of '11 that didn't grow at all for a while, then lost it's leaves. It sat in a situational dormancy all winter and most of the summer before it JUST started growing (and WELL, I might add) about a month ago.

It's especially important to keep plants like that as close to 'damp' and as far from 'wet' as possible until growth restarts; this, to help thwart the fungaluglies associated with root rot/damping off diseases. Also, try to keep the plants out of full sun - open shade is best, at least until they start to show signs of life.

The most likely scenario is: no response from the plant until spring, even if it's still viable. It probably will or has already died back to the roots and will reawaken late next spring (late May). If it doesn't, you'll know it's a lost cause.

Good luck, BTW!

AL