In all its autumn and winter glory, the Grass Garden highlights Kew’s involvement with this important plant family. In all there are over 750 different grasses within the Gardens’ living collections, including the woody bamboos and various tropical species in the glasshouses.

Behind the scenes, there are even more grasses, with over 350,000 preserved specimens from around the world filed in the Herbarium. These are the reference materials for Kew’s grass research which began over 150 years ago.

The Grass

From the imposing pampas grasses (Cortaderia) to the delicate quaking grasses (Briza), Kew’s Grass Garden displays the ornamental qualities of the foliage and seedheads of this important plant family. But it is also a valuable research resource, providing material for Kew’s botanists studying ancient cereals and investigating the genetic basis of potential fuel crops (Miscanthus).

Many of the decorative grasses are perennials that are cut back and divided in March each year. The cereals grown in the Grass Garden are all annuals. Wheat is sown in pots in November and overwintered outside before being planted out in late winter. Tropical cereals such as the millets and sorghums are sown under glass in April and transplanted into the beds in May.

The Grass Garden safeguards a British grass that is extinct in the wild. Originally found growing in cereal or clover fields, interrupted brome (Bromus interruptus) has not been seen in its natural habitat since 1963.

Studying

Which grasses occur where? How can they be identified? How are they related to one another? At Kew, scientists are studying the world's grasses to find out more about this ubiquitous and useful plant family.

Detailed listings of the grasses of particular regions, including Bolivia, Brazil, China and Egypt as well as north-east and central Africa, specify which species grow there and provide essential catalogues of the biodiversity for use by local botanists and other researchers. A CD-ROM of the grasses of Africa south of the Sahara Desert will help agriculturalists and environmentalists working there to identify the species they encounter. On a global scale, a database of all the world's known grass species has recently been completed.

Studies of different groups of grasses, such as Miscanthus or Andropogon, can explain how individual species can be distinguished and how they are related. In this way, the evolution of grasses can be explained.

In Tunisia, people use various grasses to treat human and animal ailments. Kew’s scientists are finding out if the chemicals they contain have useful anti-insect or anti-oxidant properties.