American Landscape Institute
American Society of Landscape Architects
Horticultural Research Institute
International Plant Propagators’ Society
A select group of plant propagators who promote the seeking and sharing of information about the art and science of plant propagation.
Landscape Contractors Association
Exists to provide local resources to landscape professionals to help them maximize their business potentials.
Maryland Cooperative Extension
Statewide, non-formal education system within the college of Agriculture and Natural Resources and the University of Maryland Eastern Shore.
Maryland Nursey, Landscape & Greenhouse Association
An organization promoting the use of ornamental plants, products and services in Maryland.
National Association of Landscape Professionals
Pennsylvania Landscape Nursery Association
A non-profit professional trade organization which represents Pennsylvania’s ornamental horticulture industry.
The United States National Arboretum
USDA Plant Hardiness Zone Map
The Weather Channel