Ornamental grasses

With so many varieties to choose from, ornamental grasses make lovely additions to yards. They come in numerous colors, including brown, blue, red, green and cream, and grow anywhere in size from a few inches to several feet. They are extremely adaptable, and can be used as ground cover, fillers or specimens, or border or background plantings. Most species have a long growing season, and inflorescence is often long lasting.

In order to find an ornamental grass that bests fits your needs, there are a number of factors to consider, including climate, soil type, and personal preference.

Cool season grasses

Cool season ornamental grasses include fescue, blue oat, tufted hair, and autumn moor grass. They usually begin to grow in early spring, and many remain semi-evergreen over the winter. Cool season grasses thrive when given ample amounts of water, and they may require frequent division to keep them healthy. They will grow in many types of soil, making them ideal for places in your yard where other plants won't grow.

Warm season grasses

Some popular warm season ornamental grasses include Japanese silver, Pampas, Northern sea oats, Perennial fountain, and Prairie cord grass. These grasses thrive during warmer times of the year and can withstand high temperatures and humidity. Warm season grasses, unlike cool season grasses, do not show growth until soil is warm. They usually become brown in the fall, and need to be cut back. They do not require as frequent division as cool season grasses.

Understanding growth patterns

There are two main ways that ornamental grasses grow; they are either clump forming or rhizome forming. 

• Clump forming grasses, literally, grow in mounds or clumps. They usually mix well with other perennials, and are not invasive but increase in diameter over time.

• Rhizome forming grasses, also called running grasses, spread by underground stems. They can become both invasive and aggressive. Depending on how you plan to integrate ornamental grass into the landscape, make sure you are setting yourself up for future problems.

Caring for ornamental grasses

Once you have decided on an ornamental species and planted it, which is usually done in the spring or the fall, your grass will need proper care. Here are some tips that may help.

• Water. After the first season of planting, make sure that ornamental grasses are well watered. Established plants do not need regular watering, except in times of drought. Please note that water requirements vary depending on grass species, location, size, and the growth rate desired.

• Fertilizer. Lucky for you, ornamental grasses require low levels of fertilizer. In the spring, or when they resume growth, apply 1/2 to 1 pound of fertilizer per 100 square feet. A slow release fertilizer is ideal, and will ensure healthy grass throughout summer. Please note that nitrogen levels should be kept low so that "flopping" is avoided.

• Weeds. An application of mulch, which limits weed growth, should be placed around grasses. Since mulch also retains water well, it will also help to lower watering frequency. Pesticides can also be used, although organic gardening would suggest that removing weeds by hand was more environmentally friendly.

• Division. Preformed in the spring or in fall after growing season, division is usually done on cool climate ornamental grasses. Plants which have "die-out" in the center show an indication that division is needed.

• Spring cleanup. Cut back grasses to anywhere from 4 to 6 inches in early spring before summer growth begins. Grasses will begin growth earlier than if old foliage is removed from the plant.