The Drought - Ornamental Grass Garden
Choosing Ornamental Grasses
When you are choosing the species of grass that you want in your garden, you should decide what growth habit will go best in your plan. Grasses are either clump forming or rhizome forming. Check which type of grass you are planting so that you can predict what the grass will look like when it is mature. Clump forming grasses will grow in a neat mound and will stay in one place, spreading only by reseeding itself. Alternatively, rhizome-forming grass, also called running grass, has a tendency to spread rapidly around the garden. This may be an ideal growth habit for a naturalized area, but may be too aggressive for a formal garden. In addition, an important factor in choosing an ornamental grass is the way the grass responds to temperature. In The Learning Garden, most of the grasses planted are warm season grasses. Warm season grasses may take a long time to start growing in the spring, but they offer superior drought resistance and can withstand harsh sun and high temperatures. Cool season grasses grow mostly in the cooler months and go dormant in the heat of the summer. They need to be divided more frequently than warm season grasses.
Maintenance of Ornamental Grasses
One important maintenance task in caring for grasses is cutting them back. Either hand clippers or a mechanical weed whacker can be used to cut grasses down to about 5 inches tall in late winter or early spring. This allows the new attractive foliage to grow and stimulates the plant so that it starts growing earlier in the spring. Additional tasks are similar to all perennials. After planting, water the grass until a root system has developed. A few years after planting, divide grasses if the center of the clump shows little or no growth. Also, avoid adding excess nitrogen, which causes flopping leaves and lodging.
Why Plant Ornamental Grasses?
Ornamental grasses are a stunning addition to almost any garden. They come in such a wide range of size, color, and growth habit that an appropriate variety exists for most situations. In addition, there are many beautiful variegated and colored grasses to choose from. Ornamental grasses also require less maintenance than many perennials. Once established, they rarely need to be watered. Grasses need little fertilizer, if any. They are often disease and pest-resistant. Additionally, grasses offer exceptional year round beauty. The seed heads remain on the plant throughout the winter, lending a graceful accent to what may be an otherwise barren plot. Grass seed heads also serve as winter food for many birds. The dense foliage of many grasses makes them ideal for architectural aspects of a garden design, such as creating a barrier between a formal garden area and a naturalized area. Grasses can also add a vertical dimension to a garden.
Common Pitfalls in Gardening with Ornamental Grasses
Be cautious about planting ornamental grasses in areas where the dried foliage will remain near a house or garage over the winter months. Dried grass is combustible and could cause a problem in the event of a fire. Instead, use grasses in plantings at a distance from the house. Often grasses can deplete the calcium and magnesium in the soil because the foliage is removed each year. Perform soil tests to ensure that these nutrients are available to the plants in adequate quantities to prevent discoloration.
Choosing Drought Tolerant Perennials
There are many perennials that, once established, tolerate drought and continue to grow well. The year of establishment will require monitoring for water needs. These include, but are not limited to, the sedums, Verbena bonariensis Purpletop Vervain, Echinacea - coneflower, Iberis sempervirens Candytuft, Perovskia atriplicifolia Russian Sage, Coreopsis, Festuca glauca 'Elijah Blue' Blue Fescue, Achillea millefolicia Yarrow, Agastache foeniculum Anise Hyssop. Clematis also do well, will need a structure to climb on and their roots kept cool either with other plants or mulch.
To find our ornamental grass garden, exit the main door of the extension office, turn right, walk to the end of the covered area and turn right again. The grass garden faces the parking lot. The garden demonstrates the use of ornamental grasses in landscaping design. One design goal of the ornamental grass garden was to disguise the air conditioner. This was accomplished by several methods. First, the large horizontally banded grass in the opposite corner of the garden draws the eye away. This is Miscanthus sinensis 'Strictus'. Also, the eye is drawn upward by the feather reed grass located behind the air conditioning unit. The three fountain grass plants in front (Pennisetum alopecuroides 'Hameln') further conceal the air conditioner. Although grasses are the stars of the garden, other perennials were planted to provide more interest in the spring and early summer when grasses are just starting to grow. In addition the perennials echo the colors in the grasses. For example, the yellow chrysanthemums and white deutzias harmonize with the cream and gold shades of the variegated grasses.