I found out about this from a local photographer's mailing list.

There is an orchid show in Nashua Feb 13 and 14. On those days the show will be open to photographers an hour before the main show opens, from 8 - 9 A.M. on both days.
As I understand it, strobes and tripods are permitted.

For info see http://www.nhorchids.org/show2010/show2010.htm