。
She planted an osmanthus tree in the garden.
Literal
She [topic-は] garden [in-に] osmanthus [object-を] planted.
木犀 (もくせい) is the osmanthus or sweet olive tree, prized in Japan for its intensely fragrant blossoms in autumn. The 金木犀 (kinmokusei, golden osmanthus) variety is especially iconic — its scent is one of the quintessential markers of autumn in Japan. 植える ('to plant') is the standard verb for putting plants in the ground.