Ask Mr. Smarty Plants

If deer damaged your "mother plant" for Zanthoxylum fagara (lime pricklyash), then the greatest danger your little sprouts face is deer. We would suggest delaying at least a season until transplanting. Ordinarily, we recommend transplanting woody plants in late Fall and early Winter, while they are semi-dormant. In this case, if you can keep the new plants in pots with sufficient room for root growth in an area not accessible to deer, it would probably be well to let another year roll by before you attempt it. Even then since, as you say, replacements would be difficult to come by, you might consider some sort of barrier, like wire fencing, around the nascent plants. Plants don't read, it is not surprising that the original tree survived a freeze, contrary to published opinion. It may be in a sheltered location, or simply tougher than others. If you would like for it to be a source for futher propagation, you should also find a way to protect it from a second attack by the deer. 

Our favorite website for plant propagation is this one from North Carolina State University Horticulture Information Leaflet Plant Propagation by Stem Cuttings: Instructions for the Home Gardener. From a nursery company website plantcreations.com we excerpted this information:

"You may read on about all of the wonderful features of wild lime, but we do not sell it anymore.  It has been found to be a host plant for Citrus Greening disease, which is just another nail in the coffin of the citrus industry in this part of the state."

This nursery is in Florida, but that might explain why you find it difficult to locate the plant in nurseries.  

Follow the plant link to our page on Zanthoxylum fagara (lime pricklyash), where you will learn about the conditions it needs, propagation, etc. This plant blooms yellow or green January to June, requires low water use and part shade. More information on it is found in Natives for Your Neighborhood Zanthoxylum fagara. Here are some pictures from Google