Grasses

Come summer we are mindful of the plants around us in different ways: the leaves appear on the trees, sometimes the flowers appear first and the lawn needs to be mowed. Now I have ignored garden pursuits, not for any reason than I want to focus on the concept of ‘lawn’. What is a lawn? Well it is a managed grassland, probably originally fenced and used to feed livestock. In Europe the lawn as a managed plot of grasses, became associated with the aristocracy. From the Middle Ages onward these intensively managed grasslands were associated with large estates and hardly differed from pastures. It was not until the invention of mowing machines, did closely shorn grasslands take on their current appearance.  Their significance in modern culture appeared shortly after the work week was shortened and leisure time increased (so claimed the authors of a Wikipedia article). Ideally lawns are green and made up of grasses. They are durable expanses, that some associate with nature, or the interface between built landscape and nature.

Lawn grasses are largely the purveyance of the plant breeders. There are relatively few actual species used as the best lawn grasses. Kentucky Bluegrass, (Poa pratensis) an introduction from Europe is one of the most successful cool season grasses used, both past and present. Bentgrasses (Agrostis species), Ryegrasses and Fescuses follow. All are introduced and all are now part of the Nova Scotian flora as naturalized species. Other, native grasses may also be used at our cooler latitudes. These are the reed grasses (Calamagrostis spp.) and hairgrasses, (Deschampsia spp.).

The grasses are one of the larger families of plants in Nova Scotia, with more than 140 species, subspecies and varieties present. The split is almost even with slightly more native species. Grasses if left free from mowing, have long linear leaves at the base of the plants or along the jointed stems. The flowers are formed in clusters usually at the top of the plant. As grasses are largely wind-pollinated, there are no petals nor sepals associated with pollinator attraction. The individual flowers or florets are reduced in size and modified in structure. Generally a hand-lens is recommended to see the flowers and their form.

Grasses are significant to us as providing some of the staple crops. They were amongst the first agricultural crops: rice, wheat, barley, rye and corn. They are also significant in the natural landscape. In Nova Scotia they dominate meadows between streams and forest. Coastal grasslands are called saltmarshes, with species especially suited to salt water, fog and spray.

In our managed landscape they may be used to add texture to gardens. Grasses with slolons make good recreational lawns that are kept mowed. Other species form rounded clumps that are best planted where height and texture are desirable. Grasses are also used to provide motion and colour variation. One just has to watch the rippling in a field or meadow under gentle breezes to recognize their inherent beauty.

Thanks to Sandra’s artistic eye (and video) for inspiring this piece.

Calamagrostis, bluejoint photo by Ross Hall

Cordgrass zonation in saltmarsh, photo by Martin Thomas

Ammophila, dunegrass, photo by Martin Thomas