http://www.usna.usda.gov

This arboretum was established by an act of Congress and is administered by the U.S. Department  of Agriculture, Agriculture Research Service.

Located in Northeast Washington DC, consisting of 446 acres, it serves as an institution of scientific research
and education. Research is conducted with cooperative programs in collaboration with many state universities throughout the country.

Many genetically improved crops and ornamentals have resulted from these research programs. These plants with improved qualities have been subsequently
patented and released for the consumer retail market.

Other than research, there are many excellent showcase and demonstration gardens on ornamental, trees, shrubs, herbs, and bonsai. These gardens are a great resource for all gardeners.

The National Arboretum has an extensive collection of heirloom roses. These 'old variety roses' usually bloom in spring. This is a good time to take in the splendor and exquisite fragrance of these old time roses.

Related article:  National Herb Garden