Charles W. Culpepper, 91, a retired Department of Agriculture botanist whose generosity enabled Arlington County to establish Culpepper Garden, its first institution for the elderly, died of arteriosclerosis Tuesday at Northern Virginia Doctors Hospital.

In 1971, Mr. Culpepper agreed to sell his home and adjoining property for half its commercial value to the no nprofit Arlington Housing Retirement Corporation for a housing project for the elderly. Until then, Arlington was the only county jurisdiction in the metropolitian area without such a facility for the elderly.

For more than 45 years, Mr. Culpepper had raised daffodils, day lillies and azaleas on the 4.8-acre wooded plot, which he sold from his home for 50 cents a bunch.

Mr. Culpepper was born in Wadley, Ala., and grew up on his father's cotton farm. He earned a baachelor's degree from Auburn University in Alabama and did postgraduate work in horticulture at the University of Chicago.

He joined Agriculture in 1920, where he specialized in food preservation. He was the author or coauthor of more than 100 Agriculture Department publications dealing with the canning, dehydration and freezing of food. He retired in 1955.

Mr. Culpepper was active in a number of flower societies and frequently served as judge in local flower shows. He was active in the Unitarian Church.

His wife, Anna M., died about 10 years ago.

Survivors include two daughters, Sarah C. Anspach of Vienna, Va., and Myra A. Henry of Alexandria; a sister, Inez Chamption of Atlanta, four grandchildren and two great-grandchildren.