Inland Sea Oats (Chasmanthium latifolium): A Seasonal Look

I love this plant.

It’s a beautiful shade-loving grass, excellent for erosion control, prized by wildlife for cover and seeds, and a water-wise choice for gardeners.

Inland Sea Oats, Chasmanthium latifolium, is the go-to plant for so many difficult garden situations.

What’s not to love about that?

Native to a large swath of North America, this grass forms a dense cluster requiring little effort by gardeners throughout its growing season. Let’s take a look at how this valuable wildlife and landscape perennial performs throughout the year–A Seasonal Look for Inland Sea Oats.

Fresh, green stalks appear in late February or early March (in Austin, Texas) after winter dormancy and gardeners’ pruning shears.   Those fresh, verdant shoots will emerge later if you live and grow further north.

I usually wait until I see the bright green sprouts of new growth from the basal clump before I cut back the previous year’s growth.  However, one can prune before–it’s really a matter of aesthetics and available time. The dormant beige grass does get a bit tatty toward the latter part of winter so if that’s a problem for you whack away to the ground whenever the mood strikes! 20120202_16_cropped_4474x3299..newInland Sea Oats is attractive  in winter,  but it’s a good idea to plant it in companionship with evergreens,

…just because it’s nice to have some botanical interest while the Oats are dormant.

During the spring months,  Inland Sea Oats grow,

…and grow.  The foliage reaches two-three feet in height.   Seed heads develop in the late spring and early summer, adding texture and grace to the lovely grass foliage.

Through most of summer, the foliage and seeds share the same brilliant green coloring.

Elegant and lush during the hottest time of the year, Inland Sea Oats grass is drought-tolerant, requiring little irrigation.  In my gardens, soaker hoses lie along the root zone of most, though not all of my Inland Sea Oats groups and receive irrigation once or twice/month. I grow several groups that receive no irrigation at all and they endure our long, hot summers just fine.  In fact, it’s a greater problem if the Oats are over-watered. If watered regularly and year round, a greater percentage of Oats seeds will germinate, thus plenty of seedlings develop.  This might be desirable in a spot where immediate erosion control is desired, but probably not for most home garden situations.  I remove those seedlings which grow in unwanted places in my gardens,

…but I haven’t found the Inland Sea Oats particularly troublesome to control.   This grass tolerates a variety of soil types and transplants easily.   Just recently, I separated and transplanted a group of three from another mature cluster into a spot which gets little direct sun.

Peeky looking for now, they’ll return with full vigor in spring.  Inland Sea Oats perform best in shade or part-shade.  They tend to fry when planted in full Texas sun, though in northern latitudes, the sun isn’t quite so unrelenting.  It’s good to have a lovely and reliable shade plant, so use it in those spots where many plants won’t thrive–you’ll always be happy with Oats in a shady spot.   Beth at Plant Postings in Wisconsin recently profiled Northern Sea Oats (another common name) for her “plant of the month” choice. It’s always interesting visiting a garden with a different climate and soil composition to review how a plant fares.  C. latifolium is as gorgeous and valuable in Wisconsin as it is here in Texas. It’s a fabulous grass for many places.

As summer wanes and the days shorten, the seeds of Inland Sea Oats transform from the their summer vivid green,


…to the autumn’s toasty beige.


I think my favorite part of that transition is during the actual color change,

–some seed heads are green and some are tan.  It reminds me of a lizard in mid-transformation from green to brown.  I really like that.

Once the seeds have morphed to autumn beige, Inland Sea Oats is even more striking in the garden.

Until a hard freeze ushers winter dormancy, the foliage remains green, though some yellowing of individual blades of grass is normal. Also in late fall/early winter, the seeds begin dispersal, either because of critter munching or seeds dropping.  The seed heads end up as little inverted “Vs”s atop the grass blades.

Inland Sea Oats has so many good qualities, besides its good looks and its water-wise and hardy nature.  Highly deer resistant,  (go eat something else, Bambi), it’s the host plant to several butterfly species.  The stalks with the seed heads are also quite pretty in flower arrangements.  I’m not one to pick flowers from my gardens for indoors, but on the rare occasions that I do, I always add some Inland Sea Oats to pop into the vase. Whether the seed heads are vivid green or tawny-tan, the stalks add beauty and interest to any flower arrangement.

So there you have it:  a year in the life of the Inland Sea Oats.  A grass that most gardeners (and their garden wildlife visitors) will enjoy.









Foliage Follow-up, May 2014

We’ve received a little rain here in Austin, Texas and so continue our verdant spring before the summer heat fries everything in the garden.  I particularly like this lush threesome of the glossy, dark green-leafed Star Jasmine vine, Trachelospermum jasminoides, fronted by the soft, graceful Inland Sea Oats, Chasmanthium latifolium, further fronted by an arching American BeautyberryCallicarpa americana.

I’ll remove the Inland Sea Oats next year to give the Beautyberry room to grow. For now, I  like the array of foliage these three plants provide in this shady spot.

Sedum, Sedum potosinum, is delightful in the garden; its delicate, fleshy foliage hugs the ground and rocks as it spreads.  It is attractive before it blooms,

and during bloom time.

All of the Fennel plants in my gardens are still gorgeous this May.

I’ve seen a few butterfly caterpillars chomp, chomp, chomping, but apparently not enough to eat the Fennel to the ground.

This Pale-leaf Yucca, Yucca pallida,  

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echoes the yellow of its home with stripes along the edges of its leaves.

I fell in love with the Corkscrew Rush, Juncus effusus, when I visited another garden.

It requires more watering than I typically tolerate from my plants (twice/week during our summers), but I don’t consider that onerous and this sedge plant is a fun addition to my gardens.

I enjoy the play of late afternoon light on this Soft-leaf Yucca, Yucca recurvifolia.

I have several of these non-native yuccas in my gardens and appreciate their tolerance of my somewhat heavy soil.

The pairing of the bright green, tropical foliage of the not-yet-in-bloom Turk’ s Cap, Malvaviscus arboreus, with the gray-green, fuzzy Heartleaf Skullcap, Scutellaria ovata ssp. bracteata, was a gardening serendipity that I’ve encouraged.

Finally, there’s little but foliage going on here–and such a nice variety of shape and form, if not color.

At the far left is the soft, silvery Mexican Feathergrass, Nassella tenuisima, with spiky  Iris flanking its right.  A tiny-leafed, ground-hugging Thyme completes the trio.  Two plants from the Malvaceae family, Lemon Rose MallowHibiscus calyphyllus, and Turk’s Cap fill the center/right section of the photo.  The foliage of those two are similar–wide and heart-shaped.  To the right and front of the photo, Fall Aster, Symphyotrichum oblongifolium and Texas Craglily, Echeandia texensis, both sport foliage which contrasts with the tropical looking Malvaceae plants: the Craglily’s slender grass-like lily leaves and the perennial aster’s narrow leaves.

Actually, if you look closely, you can see some blooms–at the top-center of the plant group is a cluster of Heartleaf Skullcap–its blue/purple flowers and fuzzy, gray-green foliage in total contradiction to everything else.

Thanks to Pam at Digging for hosting the May salute to foliage.

Permanent Impermanence

Recently I read the delightful biography about and  chronicle of Beatrix Potter and her life as a gardener and naturalist: Beatrix Potter’s Gardening Life, by Marta Mcdowell. Most people know Beatrix Potter through her “Peter Rabbit” series of children’s books, but she was also an important conservationist whose land comprises most of the Lake District National Park in Great Britain.  In one chapter of Beatrix Potter’s Gardening Life, McDowell is discussing Potter’s penchant for a garden “makeover.”  McDowell called that need for change in the garden “a permanent impermanence.”  Those  who garden understand that gardens are journeys, not destinations. We continually amend and refresh sections or entire gardens and for many different reasons.  We augment our gardens because of overgrown plants or development of too much or too little shade or sun. We refine our gardens as our aesthetic choices evolve or because we want plants appropriate for the changing needs or conditions of our gardens.

Earlier this spring, I decided to remove all of the Berkeley Sedge, Carex divulsa, that I had planted in my gardens.

I discovered  Berkeley Sedge while employed at the  Green Garden at Zilker Botanical Garden  and liked its hardiness, evergreen growing habit and attractive seed-heads. I bought small pots and planted them in various places on my property.

In the first few years, I was pleased with the sedge; it added structure and foliage interest  and Berkeley Sedge is drought tolerant.

There is a garden space in the Green Garden titled “Hill Country Shade” in which scads of  Berkeley Sedge seeded out.  Aside from the fact that I philosophically disagreed with the non-native Berkeley Sedge  planted in a garden touted as “native,” I also found I was constantly weeding out the seedlings produced by those sedge plants.  It was one of the more persistent chores of that job–pulling one seedling up, it seemed as if six more appeared.  One winter day, I met a California landscape designer and we visited about that plant.  She mentioned that the Berkeley Sedge was labeled  an invasive in California and asked if it was labeled so here in Texas.  I didn’t think so and later checked and according to Berkeley Sedge, Carex divulsa, was and is not considered an invasive plant in Texas.  San Marcos Growers in California originally tagged Berkeley Sedge as native to California, later concluding that it is not a native sedge.  A quick Google search shows two different sites, Pacific Horticulture and  state definitively that this plant is invasive and spreading throughout California.

Back to my gardens. After several growing seasons in which those attractive seed-heads developed and dropped seed, I noticed baby Berkeley Sedge everywhere.

Obviously, the density of seedlings was greatest near the spots where the sedge was growing, but I’ve found rogue seedlings in all parts of my gardens.  I water my gardens infrequently and for several groups of  Berkeley Sedge, the only water received comes from the sky.  And still, lots of seedlings.

I’m in the process of pulling those seedlings as I see them and as new seedlings develop, but it will take some time.

To be clear, I have other plants that could be described as invasive:

Heartleaf Skullcap, Scutellaria ovata ssp. bracteata,

definitely qualifies as an aggressive grower and invader!

Yarrow, Achillea millefolium,

spreads magnificently.

I continually weed out the always obnoxious, except when beautiful,  Inland Sea Oats, Chasmanthium latifolium.

And the ubiquitous (in my gardens), Lyreleaf Sage, Salvia lyrata, appears throughout my property.

These plants seed out or spread  and I don’t mind. Perhaps I’m more tolerant of these particular “invasive” plants because they are all native to this area–they belong here and I’ve cultivated a situation in which they thrive.   I use them as I see fit in the garden–pulling them up where I don’t want them and transplanting them where I do.  I am a practitioner of  the constant refreshing and reworking which is that gardeners’ creed of permanent impermanence.  I have no choice.  The garden is dynamic– an organism in perpetual, organic motion, responding to environmental changes and sometimes, gardener whimsy.

Or not.  I routinely pass plants which spread  to other gardeners or toss unwanted seedlings in the compost for future use as soil amendments. But with the Berkley Sedge, I decided that I didn’t want a non-native to become a pest plant in my gardens or possibly, surrounding landscapes.  Much like my decision to remove the Berkeley Sedge in the “Hill Country Native” space, I  removed a potentially aggressive plant because of my concern about its spread  and because I prefer to use mostly native and non-invasive non-natives in my personal gardens.  Taking out the sedge and adding “new” plants to the area will alter the feel of those spots–adding blooms and varying foliage.

One of my last projects at the Green Garden was removing the Berkeley Sedge in the “Hill Country Native” garden and transplanting as much as possible to a formal, rocked in space, located in deep shade, to serve as a demonstration of a low water lawn alternative to the water-hogging St. Augustine grass so common here in Texas.  Despite some misgivings about Berkley Sedge in a garden, I think it has value as a an alternative “grass” lawn–especially if the seed heads are kept in check and not allowed prolific procreation.  I haven’t visited ZBG since leaving that job a year ago, so I don’t know how that Berkeley Sedge lawn has fared, but I’ll bet it’s growing well.  I only hope it isn’t spreading too much.

Removing the Berkeley Sedge in my gardens allows me the opportunity to rethink some small sections of larger garden spaces. I didn’t run out and purchase anything new,  I dug up and separated favorites from my gardens and recycled them  in place of the sedge:  Heartleaf Skullcap paired with a common, non-native pass-along day lily,

lovely native Yarrow,

and native to West Texas, Mexican Feathergrass, Nassella tenuisima.

I love all of these plants and use them repeatedly in pockets throughout my gardens.  Each will require reining in at some point, but that will be another opportunity to observe, learn and experiment. And maybe, to garden with something new.

Permanent impermanence. As the Berkeley Sedge established and multiplied itself, I wrest control of the developing problem (as I defined it) and revised the landscape to better reflect my desires for my garden.

I’m not a purest. I grow many non-natives in my gardens.  I transplanted a ‘Nana’ Nandina from a  garden  in which the signature plant, Barbados Cherry, froze completely this past winter. When I thought the Barbados Cherry died, I welcomed the opportunity to diversify  and redesigned the garden with a more varied set of native plants.  In re-imagining that garden, I understood how out-of-place the ‘Nana’ would be,

so after I pulled up two more Berkeley Sedge in another section of the front garden, I transplanted the ‘Nana’ to that spot.

Permanent impermanence. I augmented two gardens to better reflect their evolution and my desires.

Several years ago, the native Texas Sedge, Carex texensis, moved into my front garden, but inconveniently and stubbornly, in a pathway. As part of my recent garden reconfiguration,  I transplanted the Texas Sedge clumps to a different spot. They’ve struggled a bit, but  I think they’ll survive.

The foliage is finer than the Berkeley Sedge and they aren’t as consistently evergreen– they were nipped by the last hard freeze on March 2. Texas sedge doesn’t spread rapidly, either.  I don’t find them quite as attractive as the B. Sedge (sacrilege!) and I suspect that’s why they’re not commonly found in the commercial nursery trade.  Pretty sells.

Constantly evolving, the garden reflects life and nothing is permanent.  Conditions change and the gardener responds. Gardeners follow fads and styles of gardening, always longing for  that newest, cool plant to pop the palette of the landscape, sometimes regretting that decision and action.

Tastes change.  Styles change.  Needs change.   We learn as we garden and our gardens reflect our growth.