Ornamental grasses are a broad category, which also includes ‘grass-like’ plants. Grasses are easy to grow and provide year round interest. They are selected and enjoyed for their fresh green shoots of spring, the dramatic foliage of summer, the lush colors of autumn, and the feathery maturity in winter.

The majority of grasses used for ornamental garden use are perennials. These grasses grow for more than two seasons and many are long lived and persist for decades. There are some grasses that are annuals and because of their bold foliage or color they are used as other annuals would.

Grasses are either warm season or cold season depending on when they actively grow. This is important to know for providing the correct maintenance.

SELECTING

When selecting a grass for your garden do as you would for other shrubs. Know your: sun exposure, the size you have to plant and the mature size of the grass you select (make sure they match), and the soil conditions.

PLANTING

Planting is relatively easy. They are not fussy about soils and will adapt to existing soils but generally grasses thrive in soil rich in organic matter. Careful not to apply high nitrogen fertilizer. This will cause quick growth causing them to be floppy and weak stemmed. Fertilize with organic fertilizer or composted manure to start out the first season but after that let the grasses adapt. Plant at the same depth as was in the nursery container.

Grasses do require well-drained soil. If you do have a poorly drained soil amend the soil or mound topsoil above the existing soil and plant on the mound.

MAINTENANCE

Many grasses once they are established are generally drought tolerant. Their growth can be regulated by the amount of water they receive. An example of this is Dwarf Pampas Grass. When left with minimum water it will achieve a height of 3 to 4 feet but when well watered it can reach up to 6 feet. Cool season grasses need consistent watering if they do scorch cut them back by one third and let them flush new growth.

SHOULD YOU CUT YOUR GRASSES BACK?

Acorus-Sweet Flag                               evergreen         trim damaged tips

Alopecurus-Foxtail                                cool season     trim damaged tips remove old foliage in fall

Arrhenatherum-Bulbous oat grass          cool season     cut back in late summer

Arundo-Giant Reed                               warm season   cut to the ground in late winter

Briza-Quaking grass                             cool season     cut back flower in summer foliage several times

Calamagrostis-Feather reed grass          warm season   late winter

Carex-sedge                                        deciduous        mid-late winter

Carex-sedge                                        evergreen         trim only damaged tips ¼ to 1/3 no more

Cortaderia-pampas grass                      evergreen         light clean up in early spring          

Cyperus                                               evergreen         light clean up, don’t cut down

Deschampsia-Hairgrass                        cool season     early fall

Elymus- Lye grass                               cool season     cut back several times a year

Erianthus-Plume grass                          warm season   late winter

Festuca-fescue                                    cool season     early fall or spring

Hakonechloa                                        warm season   late winter

Helictotrichon-Blue oat grass                 evergreen         trim damaged tips and foliage

Imperata-Blood grass                            warm season   late fall

Juncus                                                evergreen         trim damaged tips and foliage

Miscanthus-Maiden grass                     warm season   mid-late winter

Molinia-Moor grass                               warm season   mid-late winter, likes acid soil

Panicum-Switch grass                          warm season   late winter

Pennisetum-Fountain grass                   warm season   late winter

      Note: Purple or red fountain grass is an annual and will not come back!

Phalaris-Ribbon grass                           warm season   late winter, careful it is invasive

Scirpus-Fiber optic grass                      warm season   cut back late winter

Stipa-Feather grass                              evergreen         trim only damaged tips and foliage

Typha-Cattails                                      warm season    late winter

 Bamboo: They are a whole subject on their own. Some are evergreen and at the most need trimming others go dormant in the winter and need cleanup and trimming in the late winter

Cutting back is 1-4 inches from the base.

Trimming is only the parts of the foliage that is ragged or torn. The evergreen grasses should not be trimmed back more than ¼ to 1/3 of their foliage length, leaving 2/3 to ¾

Propagation is possible on most of the grasses by division in late fall early winter