The short answer is yes. I had over 800 Rugosa seeds from three different plants last fall. I gave them a warm treatment at room temp for 60 days and then a cold treatment in the fridge. None of the seeds germinated during the warm treatment and the earliest ones started germinating after about 6 or 7 weeks in the fridge. The later ones took between10 to 14 weeks in the fridge. I have some seeds that are just now germinating and they have been in the fridge since Dec 1st.

I would recommend at least a 30 day warm treatment, but you may want split the seeds and try half with warm treatment and half without.

I am going to assume that the Red Japanese is R.rugosa "Rubra" and that the White Japanese is R.rugosa "Alba". But if Father Hugo is the rose IÂm thinking of, itÂs not a Rugosa itÂs an R.hugonis. Is it yellow? Neither is Father David, it is an R.davidii. They will be very different roses than the Rugosas and they will not repeat bloom. Check them out on Help Me Find Roses. I would treat the seeds the same anyway.

Paul

Here is a link that might be useful: Father Hugo's Rose