Rooting rugosas

Hello,

I have some special rugosa roses that are rooting. It has been more or less 3 months, but I’ve never rooted rugosas before. Ought I leave them covered until next year, or start to gradually expose them to air. I heard that rugosas take a longer time to root, or was it that it is harder to root them. I had so many of them, and only a few actually survived up to this point. I hate to lose them all.