this is hard to answer without a photo of your den, there are a couple that like a dry spell. You said it came from a box store, so most likely an evergreen type, but could be a nobile which would like a dry spell. Nobile types bloom close to the cane and up and down the whole cane, while evergreen types put out a bloom spike. Old canes can rebloom. You might want to do a search on dendrobium care, there alot of different types of dens with different cultural needs.