Too bad that happened. You can root cuttings in the fall/winter you just need to provide bottom heat. It's the same process you use for rooting during the warm months. You are just providing an artificial heat source. You can get a seed mat at some nurseries or online. A small one runs about $20. You can also use the heat mats made for reptile cages but they aren't any better and are more expensive. I don't bother using a thermostat and haven't had any problems.

Unless you graft it back onto the plant, Karyn is spot on. Bottom heat is essential and do not water after soaking in water for a few hours and then planting in wet soil. Even if it does not show shigns of starting, watch for roots. It may go dormant, but if the roots get started it will be back in spring. Leave it dry after it dries out until spring. My Valentine is an outstanding white with red fringe. I find that whites are the easiest to root and are more hardy than say reds. Put a few holes in the bottom of the bottle so it does not collect water. Water completely the first time and then let it dry out.

Thank you for the input.

I decided that since he'd done such an amazing job rooting it the first time that I'd send the cutting back to the grower to re-root it for me, or let him send me a replacement if that doesn't work.

The previous two rooted cuttings I bought--Wildfire and Kimo--have stalled, maybe from the cooler nights, but they are also getting slightly more shriveled. Their roots were no where near as developed as the My Valentine's. My confidence is shaken by this so I decided to pass on trying to root the cutting myself.