Longwood Gardens, Botanical garden in Kennett Square, Pennsylvania.

Longwood Gardens is a botanical garden in Kennett Square, Pennsylvania, covering about 1,000 acres (405 hectares) with meadows, conservatories, and landscaped grounds. The site displays plant collections from different climate zones and changes its appearance through the four seasons.

The land was bought by Quaker farmer George Peirce in 1700; his grandsons Samuel and Joshua planted an arboretum in 1798 that by 1850 held one of the country's finest tree collections. Pierre S. du Pont purchased the farm on July 20, 1906, to save its trees from a lumber mill, and opened the garden to the public in 1921. He created the Longwood Foundation in 1937; trustees took control in 1946.

Longwood's name comes from "Long Woods", the wooded area where, before the Civil War, enslaved people fleeing the South found shelter on the Underground Railroad, supported by local Quakers. The garden hosts hundreds of horticultural and performing arts events each year, from flower shows and gardening demonstrations to concerts, organ and carillon recitals, musical theatre, fountain shows and fireworks. A tuition-free two-year school of professional horticulture trains students on site.

Wide paths run through the property and allow access to most areas including the conservatory buildings. Guided tours and educational offerings provide information about the plant collections and design methods.

The conservatory structure divides into rooms with different climatic conditions ranging from tropical to Mediterranean zones. Seasonal flower displays fill these areas with color and form depending on the time of year.