The Sherardian Professor was ex-officio Keeper of the Botanic Garden (originally the Physic Garden, founded in 1621), the oldest in the country, situated near the 'old' Botany School near Magdalen Bridge. Darlington also established a Genetic Garden in 1954, closer to the new Botany Department in the Science Area, for hybrids, variegated plants and plants used for chromosome studies.

The correspondence below relates to specimens for both gardens, though the variegated plants were intended for the Genetic Garden.