Question
Is there a resource that speaks to which Old Garden Roses grow best on new wood vs. old wood?  And for that matter, is there a set definition of old vs. new wood?

Answer
Roses grow mainly in the spring and summer so whatever new canes they make that year, those flowers that bloom that year will be on new wood. If that particular cultivar does not bloom on new wood, then it will bloom the following year on what is called the old wood. Whether or not a rose blooms on new or old wood depends on the rose itself. The blooms are no different or better whether they flower on new or old wood. If a rose makes large healthy flowers it has no bearing on when it blooms. Lynnette