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Ornamental Grasses

By Barry Fugatt

Brief History and Overview

Ornamental grasses began their meteoric rise in popularity in the 1980’s when Wolfgang Oehme, a German born landscape architect began to showcase their many garden attributes in public gardens in and around Washington, D.C.

Mixed Grasses

Grasses soften look of a garden

Today, ornamental grasses have become a staple in well-designed gardens. Home gardeners and professional designers love the soft natural look and the trouble-free nature of this large, versatile group of plants.

Grasses seem to magically lend a natural, relaxed feel to gardens. This occurs partly because of theirgraceful and fine-textured forms. Their appeal is further heightened by the unique manner in which their fine textured foliage seems to catch light and breezes, providing interesting color and movement to the garden. It’s a wonderful treat to view sunlight streaming through the soft, fluffy plumes of Maiden Grass in the early morning or late afternoon. Likewise, it’s a lovely experience to witness the gentle swaying of super soft Mexican Feather Grass foliage being swayed by the slightest breeze.

Add to this their freedom from insects and diseases, plus their ease of culture and it’s easy to understand the growing appeal of ornamental grasses.

Ornamental grasses fit into the herbaceous (non-woody) category of earth’s vegetation and they are divided into two categories: cool-season and warm season. As the name suggests, cool season grasses make their best growth during the spring and fall and usually become dormant or semi-dormant during the heat of summer. Feather Reed Grass and Blue Fescue are prime examples.

Warm season grasses make their best growth during long summer days and go dormant during the winter. The popular Maiden Grasses are examples of warm season grasses.

Culture

Perhaps no group of plants is more adaptable and less fussy in Oklahoma gardens than ornamental grasses. With few exceptions, they thrive in virtually any moderately well-drained and slightly acidic soil. They tend to be highly drought tolerant, requiring only a weekly watering to survive the hottest summers.

Most, but not all, grasses prefer full-sun in order to produce lots of plumes (flowers) and beautiful foliage. (See list for sun and shade tolerant grasses at end of article.)

Spring through early summer is the ideal time to plant container grown grasses. It’s also the best time to dig and transplant grasses in your garden. However, healthy container grown grasses usually can be successfully planted into early fall.

Ornamental grasses generally benefit from periodic division. There are exceptions, however such as Hakone Grass. Dig and divide grasses every three to five years. Division is a great way to get new plants to share with friends or to replant in your

Dividing grasses is simple. After digging up old plants, divide the clumps into four or more divisions. A sharp axe, machete or shovel works well for chopping through tough, fibrous grass clumps.

Refresh the soil before replanting. Work generous amounts of compost, peat or a commercially packaged steer manure into the planting site. After planting use several inches of organic mulch to hold down weeds and conserve moisture.

Grasses benefit from a yearly fertilizer application. Use a slow release product such as Osmocote in April or May. Organic fertilizers such as finished compost or animal waste also work. If a granular fertilizer is used, scatter about one cup of material in a six inch band around the base of plants. Grasses should be pruned back to or near the ground each spring. It’s best to cut them back in March or April before new growth begins. It’s a tedious process, but removing old spent foliage allows a plant to more quickly grow healthy new foliage and flowers.

Design Uses

Designers and home gardeners find new and exciting uses for ornamental grasses each year. In general however, the character (shape, size, and texture) of each grass species suggests various garden uses. For instance, large grasses, like the following examples demonstrate, clearly provide excellent screening.

Bench
Pool

A planting of large grasses also provides a rich background for dwarf shrubs and flowering perennials. Also there is no better accent plant in the garden than a large single ornamental grass.

Mid-size grasses, grows three to four feet tall, provide great charm when tucked into mixed shrub and perennial borders. The mid-size grasses used in mass or sweeps also make dramatic design statements.

Smaller grasses, those under three feet, make marvelous ground covers. They also are useful to line walks, patios, and shrub beds.

Sea Oats

Northern Sea Oats in a container

Increasingly, small and medium size grasses are being used as container plants. Decorative containers of ornamental grasses look great when placed on sunny patios, decks, and around pools.


Warm-Season Grasses Cool-Season Grasses Shade Tolerant Grasses
Maiden Grass Hakone Grass Northern Sea Oats
Pampas Grass Ribbon Grass Hakone Grass
Plume Grass Blue Fescue Feather Reed Grass
Fountain Grass Mexican Feather Grass Ribbon Grass
Japanese Blood Grass Japanese Sedge (Carex)

Suggested Reading:

  • Rick Darke. Color Encyclopedia of Ornamental Grasses. 1999. Timber Press
  • Roger Grounds. Plant Finder’s Guide to Ornamental Grasses. 1998. Timber Press
  • Roger Holmes (editor). Taylor’s Guide to Ornamental Grasses. 1997. Houghton Mifflin

See also: Great Grasses for Tulsa Gardens