Blades for Shade
Ornamental grasses complement rhodies, ferns
BY RACHEL FOSTER
Big ornamental grasses may have peaked in popularity. Even gardeners who were slow to catch on to them have come to appreciate the motion and texture they add to a garden and now find them indispensable. At the same time, they realize that grasses can eventually grow too large and floppy in fertile garden conditions. Dividing a huge clump of miscan-thus (or even simply removing it) can be a monumental task, so it is prudent not to have too many of them. Sun-and-moisture-loving giants are only part of the story, however, and we’ve been slower to recognize the role of grasses in shade gardens.
Many grasses (and also sedges, which look similar but are botanically distinct) will grow with only a few hours of direct sun a day, and some require considerably less, thriving where lawn grass would not. The textures and foliage colors of shade-loving grasses are particularly welcome in woodland gardens that are often predominately green by mid-summer, and they contrast nicely with such shade gardening staples as ferns, hellebores and rhododendrons. Best of all, the grasses that look loveliest in shade are relatively small and easy to manage.
Top of the list for sheer impact are the various forms of Hakone grass (Hakonechloa macra, sometimes called Japanese forest grass). If you have to choose just one, make it H. macra ‘Aureola,’ but all are wonderful whether plain green, gold striped, white striped or solid chartreuse as in ‘Allgold.’ If you have a slope, a pot or a wall for them to drape over, so much the better. Hakone grass tolerates all but the deepest shade, and it has a special affinity for rocks and water. It will grow in full sun in well-watered gardens, but those with yellow in them are far more beautiful in shade. Expensive but easily divisible after a couple of years’ growth, they make slowly expanding patches.
I grew Chasmanthium latifolium for years before I realized that this North American native is shade tolerant. Books say this upright, wide-bladed grass grows even in dry shade, but if the shade is heavy, it may not produce the large, dangling spikelets that make it interesting. Where there is enough light it colors up nicely in fall. Several other grasses are a good bet for dry shade if it is light or dappled. Blue fescue is useful to plant in groups between the notoriously greedy roots of birches, for example, and looks pretty with papery birch bark, whether white or brown.
I suspect that some of the smaller sedges, many of which are North American natives, have a great future as low-maintenance, plain green lawn substitutes and ground cover, but they are not widely available as yet. (I recently saw one used very effectively under trees at the Getty Center in Los Angeles.) Check out catlin sedge, Berkeley sedge and one named ‘The Beatles’ if you are interested. Are any local nurseries propagating our own woodland sedges? For now I’ll focus on a few easy to find sedges that make particularly eye-catching additions to mixed shade gardens.
Carex elata ‘Aurea’ (also known as Bowle’s Golden Sedge) is really stunning, especially in spring. A well-grown clump more than two feet across makes a bold statement. Like hakone grass, golden sedge dies to the ground in winter, but there are other colorful sedges that are evergreen. One of the best is Carex dolichostachya ‘Gold Fountains.’ It has a softer look and feel than most variegated sedges. It is also the least tolerant of full sun and drought. Please note that all the sedges that hold their color through the winter can be cut to the ground in mid-spring if they get shabby looking.
The more familiar variegated sedges include Carex oshimenis ‘Evergold’ (with a broad central stripe of cream on each leaf) and C. morrowii ‘Variegata’ and ‘Goldband’ (leaves have cream margins and a green center). These three plants, all of them evergreen, have a roughly similar form in the garden: a clump of tough, arching, narrow leaves that can grow very long and love some place to ‘weep.’ Quite different is C. m. ‘Ice Dance’, a rhizomatous spreader with broader, upstanding leaves leass than a foot high. This is a tough plant that I find most useful in dry shade, where the plant looks gracefully spare and spreads less rapidly.
For an even more different look there is Carex siderostica ‘Variegata.’ This small, deciduous sedge has short, broad leaves heavily striped with creamy white and it spreads slowly to form showy patches, looking a bit like a teeny hosta. (And beware: Snails can do considerable damage to the new foliage.) C. siderostica originates in Asia. Eastern North America has at least two seductive looking, broad-leafed sedges that show up in gardening books: Carex plantaginea and C. platyphylla are not generally available but might be worth looking for. One word of caution, especially for those who live near natural areas: Some sedges may be invasive outside their native range.
Rachel Foster of Eugene is a garden consultant and author of All About Gardens, a selection of past Eugene Weekly columns. She can be reached at firstname.lastname@example.org