Stratify them and plant them. I have a number of op seedlings of a hybrid of it with supposedly R. hugonis. THe hips ripened early (July). I put the seeds in moistened peat and placed that in the fridge for ~8 weeks. I pulled them out and many germinated. I am still growing the seedlings under lights. David

P.S. Drying of rose seeds can hurt some species (R. rugosa and R. rubiginosa)and is relatively neutral for others. I assume you seed is dried now.

Many thanks David.