From the Wikipedia page
Roji (露地?), lit. 'dewy ground', is the Japanese term used for the garden through which one passes to the chashitsu for the Japanese tea ceremony. The roji generally cultivates an air of simplicity.
Sen no Rikyū is said to have been important in the development of the roji. At his Myōki-an, the 'sleeve-brushing pine' gained its name from the garden's diminutive size. For his tea house at Sakai, he planted hedges to obscure the view over the Inland Sea, and only when a guest bent over the tsukubai would he see the view. Rikyū explained his design by quoting a verse by Sōgi. Kobori Enshū was also a leading practitioner.
The roji is usually divided into an outer and inner garden, with a machiai (waiting arbour). Typical features include the tsukubai (ablution basin), tōrō (lantern), tobi ishi (stepping stones), and wicket gate. Ostentatious plantings are generally avoided in preference for moss, ferns, and evergreens, although ume and Japanese maple are found.
Sadler argues that the roji, with its small size, harmonious proportions, and 'simple suggestiveness' served as a model for domestic Japanese courtyard gardens.