Large Flowering Rhododendron hybrids are classified in three groups:

Price Group I:
Price group I consists of very robust and winter hardy Rhododendron varieties propagated by cuttings. These varieties are quick and tall growing and get up to three metres high. They can be used for hedges as well as solitary plant.

Price Group II
Price group II contains robust varieties for Rhododendron enthusiasts. The varieties are grafted nevertheless quite quick and tall growing, richly blooming and hardy. 

Price Group III
Rhododendrons belonging to this group are grafted varieties which are often very decorative. They are mostly slow growing and not quite as hardy as Rhododendron varieties from the first group.