You did not mention how they have been kept since your purchase.

I presume they have been in containers. If so the root system is probably
wraping around the inside of the container and will most likely continue to
grow in that pattern unless you 'stress' the root system to get it to
develop new roots. Before planting make 3 or 4 vertical cuts with a utility
knife to sever the outer layer of the root system. This will encourage the
root system to grow new roots in an outward pattern.

The roses should be buried with the crown 3" below the soil and heavily
mulched. Using a liquid root stimulator will promote root growth during the
dormant period of winter.

Tim