The **sweet woodruff (Galium odoratum)** is a low woodland perennial and one of the best plants for the ground layer of a forest garden — a living green carpet for the shade beneath the canopy. **Fascinating notes:** - Its narrow leaves are arranged in neat whorls — like the spokes of a wheel — up square stems, topped in late spring by clusters of tiny white star flowers. - Fresh growth is almost scentless, but as it dries the leaves release coumarin and smell strongly of new-mown hay and vanilla. It was once strewn on floors and tucked among linen for exactly this reason. - Those dried leaves traditionally flavour the German springtime drink *Maibowle*, or May wine — though coumarin in quantity is not advisable, so it is used sparingly. - Spreading quietly by rhizomes, it covers bare soil, suppresses weeds and holds moisture, doing the ground layer's job with almost no help from the gardener.