Cathy Ludden Around the Grounds, Native Plants

The All-American Shamrock

Legend tells us that St. Patrick used a shamrock, with its three leaves on a single stem, to teach ancient Celtic peoples about the Christian trinity. There is no agreement among historians, theologians, or botanists, however, as to which specific plant is the legendary Irish shamrock.

Some believe St. Patrick’s shamrock was one of several species of clover (Trifolium spp.) native to Europe and Britain. Others claim that the true Irish shamrock is in the family Oxalis, perhaps due to a report from a 16th Century Englishman who wrote that the Irish ate “shamrocks,” and plants in the Oxalis family were known to be edible. Adding to the confusion, the Irish word “seamróg” means “little clover.”  

Today, in honor of St. Patrick’s Day, several Oxalis species are sold as shamrocks both here and in Europe, which just annoys those who insist the traditional shamrock is a clover. In 1988, someone conducted a public opinion poll in Ireland asking which plant is the true shamrock, and the results split among several plants, including two varieties of clover and at least one Oxalis, with no real majority view.

In any case, St. Patrick’s Day seems an appropriate time to nominate an American native plant as the New World shamrock. Yellow Wood Sorrel (Oxalis stricta) is sometimes called “sourgrass,” “pickle plant,” or adding to the general confusion, “lemon clover.” As a candidate for St. Patrick’s Day shamrock, Yellow Wood Sorrel certainly looks the part. 

Yellow Wood Sorrel in bloom
Photo: Ansel Oomen, Bugwood.org

Yellow Wood Sorrel is useful, maybe even pretty if you look closely, and it is found absolutely everywhere. Yes, it is a weed! You’ve probably pulled it out of your lawn, your garden, your containers, your driveway or sidewalk — maybe without knowing or caring what it is.

Like many other weeds, Yellow Wood Sorrel grows in a wide variety of habitats – sun or shade, dry or wet, and rich or poor soil. Each of its 3 leaves has a fold down the middle. At dusk, the leaves close up and stay that way until warmed again by the sun.

The little yellow flowers have 5 petals and bloom from spring through late fall. The plant produces lots of seeds in capsules that stand upright above the foliage. When the seeds are ripe, the capsule explodes, throwing seeds up to 3 feet away! 

Oxalis stricta leaves fold up at night like little pleated skirts
Photo: Courtesy of Pixabay.com 

Yellow Wood Sorrel is edible, though in very large quantities it may be mildly toxic. You really should try clipping some tender leaves, or the little yellow flowers, and sprinkling them like micro-greens on top of salads, fish, or chicken. The taste is like lemon, sour and a bit bitter, but refreshing. Tender stems and leaves may be steeped in hot water (a handful of leaves per pint of water) to make a lemonade-type drink high in Vitamin C.

Bees, butterflies, and ants make use of the flowers of Yellow Wood Sorrel, and its long season of bloom means the flowers are available throughout the nectaring season. Perhaps we should be grateful that this weed provides some wildlife benefit by stubbornly popping up in even the most manicured suburban landscapes.

Yellow Wood Sorrel is a small weedy plant that grows everywhere
Photo: T. Webster, USDA, Bugwood.org

So, the next time you find yourself pulling Yellow Wood Sorrel from all the places it doesn’t belong, think of it as shamrock and then save a few leaves for your lunch. Sláinte!

THIS BLOG IS AUTHORED WEEKLY BY CATHY LUDDEN, CONSERVATIONIST AND NATIVE PLANT EDUCATOR; AND BOARD MEMBER, GREENBURGH NATURE CENTER. FOLLOW CATHY ON INSTAGRAM FOR MORE PHOTOS AND GARDENING TIPS @CATHYLUDDEN.
Cathy Ludden Around the Grounds, Native Plants

A Cabbage By Any Other Name

Guest post by Travis Brady

Just because a plant has an unpleasant name, doesn’t mean that it lacks aesthetic appeal or wildlife benefits. Such is the case with native Skunk cabbage.

Skunk cabbage, (Symplocarpus foetidus = clustered fruit that is fetid) gets its name from the unpleasant carrion-like odor it emits. This scent is a way for the plant to attract pollinators that are lured to rotting meat. The scent is especially noticeable when the plant is injured; but don’t let that deter you from experiencing the unique beauty and utility of this native!

Skunk Cabbage (Symplocarpus foetidus), as it is lovingly known, is one of the very first plants to push up from winter’s frozen ground and is a native flowering perennial.

Often emerging in late February, the maverick skunk cabbage uses thermogenesis, the ability to use stored energy to create its own heat (up to 70 degrees F)  in order to melt through frozen ground and snow. As one of the year’s first flowering plants, skunk cabbage, usually found in old woodlands, wetlands and along streams, is a haven for early season insects. If you stroll down to the vernal pond here at the Nature Center, you can spot skunk cabbage along the wooden bridge and all throughout the wetland area.

The unique flowers appear before the leaves emerge and are characterized by a mottled maroon hood-like leaf called a spathe. Deep inside the spathe is a knob-like structure called a spadix. The spadix is actually a fleshy spike of many tiny flowers packed together. 

A burning sensation caused by oxalate crystals inside the plant may keep deer and rabbits from foraging on the leaves, but skunk cabbage is known to be sought out by bears just emerging from hibernation. In addition, turkey and geese also eat the young leaves, and the seeds from the fruits are eaten by squirrels, wood ducks and quail. 

After the flowers fade, the leaves take over. Dark green in color, the leaves are quite substantial, reaching a foot and a half wide and almost two feet long. With seeds often dropping adjacent to the parent plant it is most likely that you will see patches of skunk cabbage rather than isolated individuals.

This truly striking, bizarre, and fascinating plant is tolerant of soil ranging from slightly acidic to slightly alkaline and makes an exciting addition to any garden that has the right conditions. By providing early season growth with colorful flowers and attracting a litany of pollinators, skunk cabbage can benefit your garden, and may be just the right plant to help you daydream about warmer spring days ahead. Henry Davis Thoreau sure thought so…

“If you are afflicted with melancholy at this season, go to the swamp and see the brave spears of skunk-cabbage buds already advanced toward a new year…” “See those green cabbage buds lifting the dry leaves in that watery and muddy place. There is no can’t nor cant to them. They see over the brow of winter’s hill. They see another summer ahead.” –Henry David Thoreau

Cathy Ludden Around the Grounds, Native Plants

Barking Up the Right Tree

If you were a hungry bird looking for a high-protein snack in mid-winter, where would you go to find some tasty insects? And if you are a human desperate for something interesting to look at in the mid-winter landscape, what would you like to see out your window or along a path? To answer both questions, take a look at the gorgeous bark of our native River Birch (Betula nigra).

River Birch is a great tree for landscapes in our area. As the name implies, its native habitat is stream-side or near a pond. But it is perfectly happy in our acidic soil with average moisture. We have it planted next to the Meadow at the Nature Center, without any irrigation at all, and it is doing fine. It is also perfect in an area that floods occasionally, as long as the soil dries out in a few days, and there is plenty of sun.

Young River Birches at the edge of the Nature Center’s Meadow

River Birch can be a single-trunk tree, but it is more commonly multi-trunked, which adds some interesting variety to residential plantings. It is fast growing – over two feet per year – and can reach 50 to 70 feet ultimately. It does not pose a risk to houses or other structures, but it will drop lots of small twigs after a wind storm. River Birch has small glossy leaves that move lightly in the breeze and provided dappled shade. Fall color is golden yellow and lasts for weeks. 

A gorgeous stand of River Birches pond side – Photo courtesy of Mia Edwards

Birch trees are one of the most valuable host species for butterflies and moths, providing the critical food source for 413 species of Lepidoptera (butterfly and moth family). And that means birds will flock to your River Birch all summer to find caterpillars to feed their chicks. A birch grove is a bird sanctuary all summer with lots of food and hiding places. And in the winter, woodpeckers, nuthatches, chickadees, and many other birds will hunt in the millions of folds and crevices in the bark for over-wintering insects.

A close look at the bark reveals a food pantry for birds
Can you see where the woodpeckers have been hunting?

As River Birch matures, the bark becomes less flaky on the lower trunks, but the upper branches retain that cinnamon color and peeling texture. Don’t underestimate the ultimate size when you plant River Birch. After 20 years or so, each trunk can reach over a foot in diameter, so a multi-trunked tree will need some room.

But what a pleasure that bark is in the winter landscape!

A 20-year old River Birch shows off its “winter interest”

This blog is authored weekly by Cathy Ludden, conservationist and native plant educator; and Board Member, Greenburgh Nature Center. Follow Cathy on Instagram for more photos and gardening tips @cathyludden.

Cathy Ludden Around the Grounds, Native Plants

Lookin’ Good, Leucothoe!

Leucothoe has a lot going for it:

It is a beautiful, flowering, evergreen, deer-resistant, low-maintenance, native shrub. It works very well as a foundation plant, groundcover, hedge, tree-underplanting, or pathway lining. With all these virtues, why is this excellent plant so under-used in our suburban landscapes?

Maybe it’s because nobody knows how to pronounce it? We’ve heard it said:

Lew-COE-tho-way, Lew-COE-tho-wee, and LEW-cuh-tho – and all those from experts! We favor the first choice, but if you’re shopping for it, the nursery staff likely will understand any of those options.

Or maybe Leucothoe suffers from the horrifying Greek myth behind the name? Poor Leucothoe was an innocent young woman whose father punished her, for entirely wrong reasons (look it up!), by burying her alive, whereupon she turned into a plant! Of course, it wasn’t this plant, because this plant is native to the Eastern US, and the ancient Greeks didn’t even know it existed.

Leucothoe in early summer with Christmas fern

Whatever the reason, Leucothoe definitely should be better known. There are actually two species of Leucothoe native to the East Coast. Leucothoe fontanesiana ranges from Louisiana to New York, while Leucothoe axillaris naturally appears only as far north as Delaware. It is not easy to tell the two species apart, and there are cultivars with fancy leaf colors derived from both. We see Leucothoe axillaris sold here frequently as Coast or Coastal Leucothoe. Leucothoe fontanesiana tends to grow a little taller, so read the nursery tag to see what the grower indicates for size.

So why should you know this plant? Leucothoe is beautiful, with gracefully arching stems and shiny, evergreen leaves. It is easy to grow, and incredibly useful. It typically grows about 3 feet high, and slowly spreads wider. It is naturally an understory plant, so it is happiest in shade, but will live in sun if it has enough moisture. Leucothoe is perfect as an evergreen ground cover, especially near wooded areas where pachysandra or ivy would pose an invasive threat. It will retain moisture and suppress weeds, so you can use it instead of mulch around trees or shrubs. 

Leucothoe in winter as an evergreen ground cover

Leucothoe evolved growing in the relatively mild winters of Southeastern forests. It is a Zone 5 to 7 plant, so it should be protected from the coldest winter wind. You can use it as a foundation plant on the shady side of the house and not worry about having to prune it for size. It can drape over a stone wall or define the edge of a garden path. Pro tip: although sold in nursery pots with instructions to plant in a hole the same depth as the pot, we find Leucothoe likes to have its roots spread out wide and shallow, which makes it easier to plant around established trees and shrubs, too.

Leucothoe is great under trees and larger shrubs

Leucothoe flowers in late spring with little white bells that look like lily-of-the-valley, though the leaves hide the flowers to some extent. New leaves emerge in red or bronze shades before turning deep green. In winter, the shiny green leaves are very welcome. 

Leucothoe survives heavy deer predation in a local park

Did we mention deer-resistant? We have found Leucothoe thriving in the woods in winter in areas known to be major deer hang-outs. And on our grounds at the Nature Center, Leucothoe is the only native woodland plant that really holds its own against the invasion of English ivy. 

On the forest floor, Leucothoe fights back against invasive ivy and burning bush

So, consider Leucothoe as a native substitute for English ivy, Japanese pachysandra, vinca, or wintercreeper – all known to be seriously invasive if they reach wooded areas. Leucothoe forms a shiny, dark green skirt for the base of trees, leggy shrubs, or fences. It looks good all winter, and will still be looking good when the daffodils bloom in spring.

Lookin’ good, Leucothoe!

This blog is authored weekly by Cathy Ludden, conservationist and native plant educator; and Board Member, Greenburgh Nature Center. Follow Cathy on Instagram for more photos and gardening tips @cathyludden.

Cathy Ludden Around the Grounds, Native Plants

Winter Interest that Pays Dividends

On a cold gray winter day, when the leaves are gone and the last flower is just a memory, finding some bright color in the landscape is a blessing. Discovering “winter interest” in a great native shrub that also provides food and shelter for birds and pollinators is a win-win.

In our last two blog posts, we suggested Winterberry and American Holly with their bright berries to perk up winter views. Here is another of our winter favorites:

Red Osier Dogwood in front of the Manor House

Cornus sericea, commonly called Red Osier Dogwood or Red Twig Dogwood, is a great native shrub that should find a place in the landscape just for its brilliant red bark in winter. But it’s also beautiful the rest of the year – a true four-season plant. In mid-spring, it blooms with flat sprays of fragrant white flowers. All summer, it forms a rounded shape topping out at 6 to 8 feet tall and wide.

Red Osier Dogwood is lovely in spring and summer

In late summer, pretty white berries form to feed the birds. In fall, the leaves turn varying shades of red and purple and begin to drop from the lower branches first, revealing the characteristic red bark. As the shrub matures, you can cut back the older woody stems in spring to encourage new sprouts to come up in vibrant red for the winter show.

The newest growth is the brightest red

Red Osier Dogwood has a wide native range in the United States. It grows on river banks and in wet areas throughout the northern part of the country. It’s a great choice for rain gardens or any sunny area where water collects, especially if you want a low-maintenance natural thicket. Red Osier Dogwood will send out suckers, or shoots, that will root themselves and form new plants to fill in an area. It is an ideal choice for controlling erosion or steep banks in areas that tend to flood. But it will also grow in average garden soil and can easily be controlled by cutting off suckers as they appear.

Red Osier Dogwood with Inkberry and Switch grass on the slope in front of the Manor House

And you couldn’t find a better bird habitat!  Red Osier Dogwood provides nesting sites, berries for food, and a supply of caterpillars for baby birds. Like other dogwood species, it is a host plant for the beautiful little Spring Azure butterfly. 

So, all these features are dividends for nature while we enjoy the winter interest in our landscape. That’s a pretty good investment!

Red Osier Dogwood and Winterberry brighten a winter day

This blog is authored weekly by Cathy Ludden, local expert and advocate for native plants; and Board Member, Greenburgh Nature Center. Follow Cathy on Instagram for more photos and gardening tips @cathyludden.