Native Grasses, Sedges and Rush for the Garden

From Grass_090618

While working at Rancho Santa Ana Botanic Garden I wanted to order lots of native grasses for our native plant nursery and annual sales. I love their texture and motion, but as my boss reminded me, they are not big sellers. Non-native bunch grasses, in contrast, have achieved some level of popularity. Unfortunately some of the most popular ones are extremely invasive, and are responsible for degrading coastal sage scrub, chaparral, riparian, and even desert open space. Fountain grass, pampas grass and arundo are among the most notorious. (See California Invasive Plant Council for more information.)

For many, grass simply implies lawn or turf. Its role as food for grazing animals is understood by farmers and cattlemen. Grains feed humans directly as well. Rice, wheat, oats are just a few staples of the human diet. In fact, this remarkable group of plants feeds the world. It occurs in almost every environment, including our deserts, mountain meadows, hills and coastal areas.

It is estimated that grasslands covered about one-seventh of the state of California. The California Native Grasslands Association (www.cnga.org) states that there are over 300 species of native grasses and that 90% of California’s rare and endangered species occur in the grasslands. Furthermore, many threatened species of birds rely on our diminishing and degraded grasslands. Annual weeds, grazing and development have impacted nearly all of these grasslands.

In an earlier posting, Overlooked and Underappreciate: Native bunch grasses throughout the year in the garden, a few of my favorite ornamental, native grasses are described as they change through the year. In the next few postings I am going to describe twelve grasses and grass-like plants. I have included sedge and rush because, although they are not true grasses, they provide similar functions in the landscape. The plants, going from large to small and spreading, are:

1. San Diego sedge (Carex spissa)
2. Deergrass (Muhlenbergia rigens)
3. Canyon Prince giant rye (Leymus condensatus ‘Canyon Prince’)
4. Alkali sacaton (Sporobolus airoides)
5. Purple three awn (Aristida purpurea var. purpurea)
6. Needle grasses (Nassella pulchra, N. cernua)
7. Rush (Juncus species)
8. Fescues (Festuca californica, F. idahoensis)
9. Blue Fescues (Festuca cult. – Blue Note, Siskiyou Blue)
10. Blue grama (Bouteloua gracilis)
11. Creeping red fescue (Festuca rubra)
12. Clustered field sedge (Carex praegracilis)

First, let me state – though it is probably evident from the fact that this is my third posting on native grasses, and I have written several other articles on these wonderful plants as well – that I think they should be in everyone’s garden, and I am not talking about lawn. Native grasses are beautiful. They can have an unusual texture, form, or color. Many are a study in motion and sound. They provide habitat. They are easy to grow. They accept a wide range of garden conditions from sun to shade, well-drained soil to clay, wet conditions or dry. They typically fill in quickly and some are very long-lived. Most importantly, they belong here.

Grasses are either clumping or running. Bunch grasses are clumping, and can be described by their form. According to John Greenlee’s book, The Encyclopedia of Ornamental Grasses (1992), there are six basic categories used to describe their shapes: tufted, mounded, upright, upright divergent, upright arching and arching.

Grasses also differ in their growing season. Warm-season grasses grow when temperatures are high, while cool-season growers are active in our cooler winter and spring temperatures. In the hot, dry parts of the state many grasses take advantage of the winter and spring moisture and moderate temperatures to do most of their growing. Summer is usually marked by either a period of slow growth, or dormancy.

It is important to know the growing cycle of these plants to provide proper garden care. For example, pruning and watering warm-season growers in late summer may force them to grow when they would otherwise enter dormancy. If they are not watered, but only pruned in the fall or winter, then the plant may maintain an unappealing, shorn look for many months. Rather, it is often a good practice to prune these plants – if you are going to prune them at all – in the late spring, just before they enter their active growth period. Cool season growers, on the other hand, go dormant as the temperatures climb. Some may continue to grow through the summer with additional water, but others will just rot out in the hot, moist soils. So knowing when your grass is going to grow and when it is going to sleep will help you provide better care. It can also help with plant selection. I chose both cool and warm season grasses so that some are green at all times of the year. Just as the needlegrass changes from soft green to gold, the deergrass and alkali sacaton are greening up.

And finally, here is the first star of this group!

From Grass_090618

November 12, 2005

From Grass_090618

January 30, 2006

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February 19, 2009

From Grass_090618

June 14, 2009 – mugwort, (Artemisia douglasiana) and golden currant (Ribes aureum) will die back when the hot weather arrives. I will then prune them back, along with the San Diego sedge.

From Grass_090618