The Little Grass That Could

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Pennsylvania sedge (Carex pensylvanica): the ultimate lawn grass for shade? Photo: mgnv.org

Are you looking for a low-growing grass for a shady spot, one that could even be a lawn substitute? What about Pennsylvania sedge (Carex pensylvanica)?

Now, to be honest, it’s not really a grass (Poaceae), but a sedge (Cyperaceae), but it sure looks like one, with long, narrow, fine-textured green leaves that arch out around the mother plant. It grows to be about 8 to 10 inches (20 to 25 cm) in height if unmowed and is semi-evergreen, that is, it will remain evergreen in mild climates, but die back in cold ones, regrowing new leaves from the base in the spring. Curiously, in my very cold climate (USDA zone 3), it has proven faithfully evergreen, probably because it’s covered in snow from November to April and snow is an excellent insulator. Where it does die back, however, it recovers rapidly, sprouting very early in the spring. In fact, one common name is “early sedge!”

It also blooms early in the year, but the brownish flower spikes are soon hidden by the growing leaves and aren’t that noticeable.

A Pennsylvania sedge lawn. Photo: greenthumbyardcare.com

I’m quite amazed by its adaptability. It’s said to be a shade grass, yet it does fine in full sun as well (although only if the soil remains somewhat moist at all times). Mine is positively thriving in dry shade under conifers where little else will grow, although it’s very, very slow to spread under such conditions. In more humid soils, it will produce more numerous offsets on longer rhizomes and fill in better.

I keep reading it needs “good soil,” but I find it seems rather indifferent to soil type except maybe not liking very alkaline ones. Certainly, it really doesn’t seem to need fertilizer.

Can you mow it? Sure, perhaps twice or three times a season (much less than regular lawn grass). Probably early in the year and again in fall (it doesn’t grow much in the heat of summer). Or just let it grow, in which case it takes on a sort of swirly appearance.

Pennsylvanis sedge in deep shade. Photo: http://www.scnow.com

In the wild (it’s native to much of eastern North America, from Quebec to Manitoba in the North and Georgia to Missouri in the south), it tends to form large monotypic patches (yes, a natural monoculture!). You don’t have to force it to be a lawn, it wants to be a lawn!

Pennsylvania sedge is only moderately tolerant of foot traffic: you certainly wouldn’t want to walk on it daily or use it for a playing field.

It’s considered resistant to deer and rabbits and has no major disease or insect problems. It’s a host plant for several North American butterflies, but the caterpillars seem to do little visible damage.

As for hardiness, it grows in USDA hardiness zones 3 to 8. I suspect it is even hardier than that: time will tell!

The Downside

Ideally, you’d want a shade lawn you can grow from seed: that would be a cheap and fast way of getting results. Well, Pennsylvania sedge won’t do that. It’s slow to grow from seed and germination tends to be poor. You’d likely be wasting your time growing it that way.

This is how you would ideally buy Pennsylvania sedge: in plug trays. Photo: http://www.madrono.org.

So, what you’re going to want are plugs you could space about 6 inches (15 cm) apart in deep shade or dry conditions, 12 inches (30 cm) apart in sun or partial shade and moister conditions.

Good luck with that, though! Locally, I can only find Pennsylvania sedge in a few specialist ornamental grass nurseries in 6-inch pots: way too expensive for a lawn project. So, I’ve taken to dividing my original plant each spring to cover a larger and larger area. It’s slow-going, but getting faster as the divisions produce divisions and they too produce divisions. I’ll be there soon!

Commercial Growers

Hey garden centers! Can you wake up and start selling your clients plugs of this plant at reasonable prices? After all, there’s a huge demand for shade lawns and this is about the only “grass” that will fill the bill. If I were looking for a lawn for a dark corner and you offered trays of plugs ready to plant at a reasonable price, I’d be on it like a duck on slugs and I’m sure other gardeners would as well.

Grasses to Plant Where the Sun Don’t Shine

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20171017A Luzula_sylvatica Jerzy Opiola, WC

Greater woodrush (Luzula sylvatica) is an excellent example of a shade-tolerant ornamental grass. It will grow and even flourish in the deepest shade! Source: Jerzy Opiola, Wikimedia Commons

When you think of ornamental grasses, an image of a sunny meadow generally comes to mind and indeed, most grass species are native to prairies, steppes and other grasslands, not forests. But does that mean there are no grasses that will grow in shady spots?

Of course not! Even in the very darkest forests, there are some species of grass—both true grasses (plants in the Poaceae or grass family) and grasslike plants from other families, like the Cyperaceae and the Juncaceae—that do very well indeed, even in dry shade. The vast majority of sedges (Carex spp.), for example, adapt very well to shade.

What follows is a list of grasses that easily adapt to at least moderate shade. Most, in fact, do fine in deep shade. If you grow them among dense tree roots (i.e. dry shade), though, here are a few tips on how to get them started.

Shade Grasses

20171017B Chasmanthium latifolium HC

Northern sea oats (Chasmanthium latifolium) is a classic shade-tolerant ornamental grass. Source: laidbackgardener.blog

  1. Appalachian Sedge (Carex appalachica) zone 4
  2. Autumn sedge (Carex dipsacea) zone 5
  3. Bambou marginé (Sasa veitchii) zone 6
  4. Big bluestem (Andropogon gerardii) zone 4
  5. Black sedge (Carex nigra) zone 4
  6. Blue lilyturf (Liriope muscari) zone 6
  7. Blue moor grass (Sesleria caerulea) zone 4
  8. Blue sedge (Carex flacca) zone 5
  9. Blue wood sedge (Carex flaccosperma) zone 5
  10. Blue-green moor grass (Sesleria heufleriana) zone 4
  11. Bluejoint Grass (Calamagrostis canadensis) zone 3
  12. Bottlebrush grass (Hystrix patula) zone 3

    20171017 stauden-stade.de

    The bright yellow leaves of Bowles golden sedge (Carex elata ‘Aurea’) certainly light up a shady corner! Source: stauden-stade.de

  13. Bowles golden sedge (Carex elata ‘Aurea’) zone 5
  14. Bristle-leaf sedge (Carex eburnea) zone 2
  15. Broadleaf sedge (Carex siderosticha) zone 4
  16. Brown sedge (Carex buxbaumii) zone 3
  17. Bur sedge (Carex grayii) zone 2
  18. Bur-reed Sedge (Carex sparganioides) zone 4
  19. Bushgrass (Calamagrostis epigejos) zone 3
  20. Catlin sedge (Carex texensis) zone 5
  21. Chinese pink fairy sedge (Carex scaposa) zone 6b
  22. Common wood sedge (Carex blanda) zone 3
  23. Creek sedge (Carex amphibola) zone 3
  24. Creeping lilyturf (Liriope spicata) zone 6
  25. Creeping sedge (Carex laxiculmis) zone 4
  26. Curly wood sedge (Carex rosea) zone 4
  27. Davall’s sedge (Carex davalliana) zone 4
  28. Drooping sedge (Carex pendula) zone 5
  29. Dwarf lilyturf (Ophiopogon japonicus) zone 6
  30. Dwarf whitestripe bamboo (Pleioblastus fortunei) zone 5
  31. Eastern star sedge (Carex radiata) zone 4
  32. Feather reed grass (Calamagrostis x acutiflora) zone 3

    20171017F Deschampsia cespitosa Matt Lavin, Flickr

    Tufted hair grass (Deschampsia cespitosa) is a widely adapted grass that does fine in both sun and shade. Source: Matt Lavin, Flickr

  33. Field sedge (Carex praegracilis) zone 3
  34. Fox sedge (Carex vulpinoidea) zone 3
  35. Foxtail grass (Alopecurus pratensis) zone 4
  36. Fringed sedge (Carex crinita) zone 3
  37. Golden wood millet (Millium effusum ‘Aureum’) zone 5
  38. Goldfruit sedge (Carex aureolensis) zone 5
  39. Greater woodrush (Luzula sylvatica) zone 4
  40. Japanese Forest Grass (Hakonechloa macra) zone 4
  41. Japanese sedge (Carex morrowii) zone 5
  42. Korean reed grass (Calamagrostis brachytricha, syn. C. arundinacea) zone 4
  43. Lawn Sedge (Carex leavenworthii) zone 6
  44. Long beaked sedge (Carex sprengelii) zone 3
  45. Mondo grass (Ophiopogon planiscapus) zone 6
  46. Northern sea oats (Chasmanthium latifolium) zone 4
  47. Oak sedge (Carex albicans) zone 4
  48. Oriental fountain grass (Pennisetum orientalis) zone 6
  49. Oshima sedge (Carex oshimensis) zone 5
  50. Palm sedge (Carex muskingumensis) zone 2

    20171017E Carex pennsylvanica, Susan Harris, Flickr

    Properly spaced, Pennsylvania sedge (Carex pensylvanica) makes an excellent lawn grass for shade. Source: usan Harris, Flickr

  51. Pennsylvania sedge (Carex pensylvanica) zone 3
  52. Pheasant tail grass (Anemanthele lessoniana, syn. Stipa arundinacea) zone 8
  53. Plains oval sedge (Carex brevior) zone 3
  54. Prairie sedge (Carex bicknellii) zone 3
  55. Pretty sedge (Carex woodii) zone 4
  56. Purple moor grass (Molinia caerulea) zone 3
  57. Pygmy bamboo (Pleioblastus pygmaeus) zone 5

    20171017C Carex plantaginea Jay Sturner, Flickr

    Seersucker sedge (Carex plantaginea). Source: Jay Sturner, Flickr

  58. Seersucker sedge, plantainleaf sedge (Carex plantaginea) zone 4
  59. Silver sedge (Carex platyphylla) zone 4
  60. Snowy woodrush (Luzula nivea) zone 3
  61. Spear grass (Achnatherum calamagrostis, syn. Stipa calamagrostis) zone 5
  62. Spring sedge, vernal sedge (Carex caryophyllea) zone 5
  63. Striped tuber oat grass (Arrhenatherum elatius bulbosum ‘Variegatum’) zone 4
  64. Sweet Flag (Acorus gramineus) zone 4
  65. Tall moor grass (Molinia arundincaea) zone 4
  66. Tufted hair grass (Deschampsia cespitosa) zone 2
  67. Veitch’s bamboo (Sasa veitchii) zone 6
  68. Wavy hair grass (Deschampsia flexuosa) zone 420171017A Luzula_sylvatica Jerzy Opiola, WC