Lawn Alternative Update from the Scott Arboretum

Lawn Alternative Update from the Scott Arboretum

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Years ago I visited the Scott Arboretum to learn about alternatives to lawn and see the ones they were growing there.  (Here’s my 2008 report.)  Last month I returned for another event but made time to revisit their lawn-alt plants, too.  (Wonder if we can get that term to stick.)

First, the Prairie Dropseed shown above, which my friends at the U.Maryland asked me to inquire about.  They want to know if the Scott Arboretum burns it and horticulturist Chuck Hinkle answered, “We burn the sporobolis beds in late winter when the students are on break. The nice thing about it is that it can be done relatively quickly. The grass doesn’t create a huge conflagration (like miscanthus!) and can be controlled easier.”  I’ll pass that along, though a non-fire answer was hoped-for (U.Md. isn’t allowed to burn.)

But it’s Carexes I was most interested in checking on.  That’s the huge genus, commonly named sedge, that’s so promising as alternatives to lawn in spots that aren’t walked on.  At Scott they’ve been growing a wide assortment of them, many of them donated by New Moon Nursery, whose owner James Brown “has been very generous and is trying to promote the use of lawn alternatives,” quoting Chuck.

Above, Carex pensylvanica looking horrible. Here’s Chuck’s explanation: “The Carex pensylvanica did very well for the first few years. However, as the site became shadier under the maple trees, the plants became thinner. I tried replanting the bare spots but there just wasn’t enough light for them to thrive. So even though they say C. pensylvanica takes shade, I would not recommend it for full shade. You can see areas in the same bed where it gets more light and is more vigorous.”

Below, looking much better.


Above, C. laxiculumus ‘Bunny Blue’ also seems sparse.  Chuck wrote that it “also started out pretty well. It started to thin out when I interplanted it with Solidago caesia. Again, I think some of the plants got shaded out. I also heard that some goldenrods are alleopathic so I don’t know if that had anything to do with it.”

Above, C. platyphylla. “The same thing happened with C.platyphylla. It was doing fine until I interplanted it with Allium cernuum.”

Above, C. albicans.  “Carex albicans has been one of the best performers for doing well in a variety of sites – sun/shade,dry/moist,” says Chuck.

Above, the C. texensis looked pretty sparce to me.  Chuck says it’s “done well in a drier,sunnier spot. The habit looks a little messy – it flops but has a flat look to it. It self-sows as well.”

Above, C. appalachia.

Overall, Chuck reports that “The growth habits of different species vary greatly. Some of the small clumpers definitely take more time to fill in. C.appalachica,C.eburnea,and C.rosea are slower to fill in. C.sprengellii,C. brevior and C.amphibola filled in very quickly.  C. woodii has done well in part shade. It does not like extended dry periods, though.”

And, “Our infiltration beds using carex have generated some interest. We plan on expanding them.”

Two more of my favorites below.

Above, C. leavenworthii.

Above, C. morrowii ‘Silk Tassel.’

Thanks to Chuck and the Scott Arboretum for their work in trialing and publicizing this important group of plants as lawn alternatives.

UPDATE ON SHADE:  Carexes are a great group of plants to explore for shade situations, so after reading Laura’s comment below I decided to add photos of two of my favorites for full shade.   (Also, in the examples above, C. albicans and leavenworthii look terrific, and they’re in shade.)

SECOND UPDATE ON NATIVES AND SHADE:  “As far as native carexes for shade, I think there are some great woodland sedges. They tolerate part shade or dappled light. I’m not sure how many tolerate (or look great) in full shade. As you saw, C. pensylvanica was growing in shade but was very thin. Most do better in moist shade than dry.” That being said, here are some native woodland sedges I would recommend: C.albicans, C.amphibola, C.eburnea, C.grisea, C.laxiculmis, C.plantaginea, C.radiata, C.sprengelii.  Some other (non-native) garden sedges that do well in shade for us are C.morrowii and C.siderosticha cvs. for moist shade and C.oshimensis cvs. for drier shade.”   Chuck Hinkle

Above, a taller evergreen Carex I’ve grown for 25+ years in full shade and taken many divisions from.  It’s about 3 feet tall.  Don’t know the name but assume it’s Asian.

This is C. morrowii ‘Ice Dance,’ which I’ve also grown for decades in full shade OR full sun, and love.  Its variegated foliage brightens up shady spots, and it grows larger to produce divisions without spreading by aggressive runners (true of all Carexes, btw).  The Scott Arb also has good success with ‘Ice Dance,’ Chuck tells me.

Posted by

Susan Harris
on November 28, 2014 at 8:39 pm, in the category Lawn Reform.

    • Laura Palmer
    • 30th December 2015

    So glad to see this post Susan! With a foot of snow on the ground in NY, I’m planning next year’s garden additions and been thinking a lot about which grasses I will add–definitely that Prairie Dropseed. Too bad those carex won’t take shade–but good to know. Thanks for giving us what didn’t work too.

    • Margaret Wilkie
    • 3rd June 2016

    Thank you to Scott’s Arboretum for their lawn-alt work, but also for infiltration trials.
    Interesting post.

    • admin
    • 10th August 2016

    Very interesting observations! I have been growing a 22′ diameter circle of Carex flacca in part shade for just over 4 years now in zone 7b-ish, Vancouver, WA. When I had my garden open this year, this circle inspired considerable interest and discussion because I had not fertilized, mown, or watered it all summer (this was at the end of August). In fact, ALL I had done was occasionally raked out any of the dead grass or fallen leaves and weeded. There is more information here a out planting:

    • Evelyn Hadden
    • 25th October 2016

    Thank you for the update, Susan. I believe your woodland sedge is C. pendula.

    • Chris - PEC
    • 11th November 2016

    I like the picture here – when I Google C. pendula one site calls it a “thug” that self seeds prodigeously and warns everyone not to buy or sell it. Another site says it’s native to Europe, North Africa and SW Asia, and, quite politely, says “Drooping sedge is common in the British Isles, and sometimes uninvited in English gardens.”
    So now I’m unsure if I should try it…

    • David Feix
    • 12th November 2016

    Here in California, the Carex that works best in my opinion is C. tumilicola, Berkeley Sedge. Left unmown, it isn’t exactly low enough to walk upon, but can be mown at 3″ height once a month in summer and fills in nicely. Takes full sun, full shade, little water(1xmonthly for me in Berkeley), really idiot proof. Other Carex species such as C. pansa and C. praegacilis thinned out too much over winter without full sun, but stayed lower than C. tumilicola.

    • patricia Hill
    • 14th November 2016

    The other common name of Penn Sedge (Carex pensylvanica) is Oak Sedge, which gives a clue as to where it it found in nature–in oak savannas, a partial shade situation. It also prefers dry or well-drained soil, even sandy Black Oak savannas adjacent to Lake Michigan. Maple trees provide not only deep shade, but shallow roots, which could interfere with Penn Sedge, as well. I’m not familiar with C. albicans, but it is called Blunt-scaled Oak Sedge, a clue as to where it likes to grow. It, too, is found in dry, sandy woods in dune country underneath Quercus alba and Quercus velutina.

    • Sarah
    • 14th November 2016

    Interesting and useful post, Susan. I have C. pensylvanica under Ash, planted as plugs probably 4 or 5 years ago, and it does well, puts up with roots of Ash, which suck up most of water, and has filled in well. Does get late afternoon sun. I’ve read it grows under Oaks “in nature” so I was going to try there (I have 2 huge White Oaks) as well. Interesting that deep shade is not its preferred situation.

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