Hi Becky, Either planting the seeds in late fall (when temperatures have dropped down to 40 degrees) or planting them in the greenhouse now and transplanting them next spring would be possible options. Planting in the greenhouse may give you a higher rate of success. For growing in the greenhouse, germination will be improved if you soak the seeds overnight and remove any seeds that floated to the top. The floating seeds are not viable. A period of cold, moist treatment for 30 days (in the refrigerator) will also improve the germination rate. See the USDA plant guide on wild roses at the link below for more information.