Bought a potted Blanc Double de Coubert rugosa from a local nursery -- turns out it's grafted. Bah! My question is -- do I have to bury the graft deeply like I would a non-hardy grafted rose (e.g. hybrid tea), or is it fine to plant with graft at soil level since rugosas are extremely hardy? Also, I'd like it to sucker as a rugosa, not as the rootstock -- so that means deep planting, right? (even if top super-hardy). It's been so long since I've had a grafted rose I just don't remember all this.