Empire National Nursery  
   Growers of fast growing trees and shrubs for landscaping planting projects.
   http://www.cdr3.com/catalog

Select Plus International Lilac Nursery  
   Quebec-based grower of species, hybrid and cultivar lilacs, including heirloom and rare varieties. Ships to US. Also sells perennials.
   http://spi.8m.com/

Carlson's Gardens  
   New York grower of azaleas, rhododendrons and mountain laurels.
   http://carlsonsgardens.com/

Girard Nurseries  
   Ohio nursery specializing in flowering trees and shrubs, particularly azaleas and rhododendrons.
   http://www.girardnurseries.com

Hydrangeas Plus  
   Oregon nursery specializing in a large selection of species and cultivars of hydrangea. Includes images and information.
   http://www.hydrangeasplus.com/

Fox Hill Lilac Nursery  
   Maine lilac nursery growing over 90 different cultivars of lilacs.
   http://www.lilacs.com/

Shepherd Hill Farms  
   New York State nursery raising cold-hardy rhododendrons and azaleas.
   http://www.shepherdhillfarm.com

Wilkerson Mill Gardens  
   Specializing in hydrangeas and offering a selection of other shrubs and some trees.
   http://www.hydrangea.com/

Nantucket Hydrangea & Hydrangea Farm Nursery  
   Offers and extensive listing of hydrangea cultivars. Many varieties, a few pictures.
   http://www.nantuckethydrangea.com/

Hydrangea Select  
   Hydrangea nursery with over 75 varieties in all colors. Climbing vines, shrubs, and tree varieties, along with how-to tips for growing successful hydrangeas.
   http://www.hydrangeaselect.com/