Cathy Ludden Around the Grounds, Native Plants

What’s the Buzz?

Have you heard all the “buzz” about pollinator gardens? It seems that community groups everywhere are planning, planting, or maintaining pollinator gardens. Schools, parks, churches, and homeowners are adding pollinator-friendly native plants to landscapes all around us. Are you involved?

Pollinator Pathway garden sign

The original “Pollinator Pathway” idea was to create linked gardens through urban and suburban areas so that pollinators could travel, finding what they need to survive along the way.

The concept has grown wildly and Pollinator Pathway organizations are popping up everywhere, including locally in Irvington, Hastings-on-Hudson, Dobbs Ferry, Bedford, Elmsford, and many others.

Physically connecting pollinator gardens into an actual pathway is less important than having lots of them everywhere. From big meadows to front lawn patches to container gardens on balconies, every blooming native plant helps pollinators.

August Brosnahan and friends started a pollinator garden along the Old Croton Aqueduct
Friends of Dobbs Ferry Waterfront Park planted native plants for pollinators
Photo: Don Vitagliano

Driving this movement is recent documentation of a stunning decline in insect populations, especially pollinators. Since many of our food crops depend on insect pollination, this is a huge wake-up call for all of us. Insecticides, agricultural techniques, and loss of habitat all contribute to crashing insect populations. And since most birds depend upon insects to feed their young, bird populations also are declining rapidly.

The New York Times reports on the “Insect Apocalypse”

Unlike many other global problems, we can actually do something about this crisis — right in our own yards. Pollinator gardens are a powerful force for good. And the bonus? They are gorgeous! Every time we convert a patch of lawn, or bare dirt, or a weed-infested spot to a pollinator garden, we not only provide survival essentials for birds, bees, and butterflies, we brighten our neighborhoods with color and life.

The pollinator garden at Dobbs Ferry Waterfront Park
Photo: Nancy Delmerico
This pollinator garden replaced a lawn in Hastings
Photo: Myriam Beck

So, what makes a garden a pollinator garden? Short answer: native flowering plants. The two main classes of pollinators we are trying to save are butterflies and bees, especially native bees. Bees need flower nectar and pollen. Butterflies need nectar and host plants for their caterpillars to eat. Pollinator gardens should provide all 3 essentials: nectar, pollen, and host plants.

Native bumblebees need pollen from native plants
Photo: Travis Brady

The reason we keep emphasizing native plants is because most of these insects are specialists — they depend upon one or two specific species of plants for survival. For example, there are over 20 species of native bees that can only eat the pollen of Goldenrod! And just as Monarch caterpillars can only eat the leaves of Milkweed, other butterflies’ caterpillars are also completely dependent upon specific plant species – their “host”plants.

Swallowtail butterfly caterpillar on its host plant, Zizia
Adult Black Swallowtail on Zizia at the Nature Center

Pollinator gardens do best in sunny spots. Butterflies and bees prefer sunshine and are more active in sunny areas. Any place that lawn grass grows is a good spot for a pollinator garden.

The best plants for pollinator gardens are native meadow or prairie plants. Adapted to harsh environments, they don’t need rich soil and never need fertilizer. Most of these plants are drought-tolerant, so they don’t need irrigation once they are established, and many are deer-resistant. And we recommend perennials rather than annuals, so the plants come back every year. It is easier, and definitely cheaper in the long run, to plant a perennial pollinator garden than it is to buy, plant, water, and fertilize annual bedding plants every year.

Pollinator Garden at the Nature Center

Spring is almost here! If you are thinking about planting or expanding a pollinator garden, there are loads of great resources to get you started. The Pollinator Pathway website linked above has how-to’s and plant lists. Watch for local native plant sales. The Native Plant Center will hold its annual plant sale this year at Westchester Community College on April 30. And the Garden Club of Irvington will have native plants for sale at the Greenburgh Nature Center on May 7, plus lots of knowledgeable help on hand.

And watch this space! Over the next several months, this blog will highlight many of our favorite pollinator plants. Come see them in action at the Greenburgh Nature Center all season long!

Come visit our Pollinator Garden!
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

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

Forever Green: Native Groundcovers That Stay All Winter

Given our recent weather, you may well ask, “why should I care whether a ground cover is green if it’s under a foot of snow”? Fair question! 

In our milder winters, when snow comes and goes, evergreen groundcovers do offer structure and winter interest in the garden. And they benefit birds and small mammals, providing cover from predators and shelter from icy winds. But not so with ivy or pachysandra! Both are invasive, non-native plants that must be prevented from running into wooded areas where they smother everything! Fortunately, there are native evergreen groundcovers much better suited to our landscapes and helpful, rather than harmful, to the ecosystem.

We recently described Leucothoe, a native evergreen that can replace pachysandra as a ground cover under trees and shrubs and in wooded areas.

Another evergreen woodland plant we love is Christmas fern (Polystichum acrostichoides). Not truly a groundcover, because it stays in place rather than spreading itself around, Christmas fern can be planted densely to fill in a shady area. Deer won’t eat it, and it’s such a pleasure to see a green fern in the dead of winter.

Evergreen Christmas fern brightens the winter landscape

Perhaps the best known native evergreen groundcover in our region is Creeping Juniper (Juniperis horizontalis). Juniper is a versatile shrub that provides significant value for wildlife year-round. Its dense branches provide good hiding places, and its berries feed the birds. It prefers dry soil and full sun, but it tolerates some shade as long as the soil is well-drained. It spreads at a moderate rate, and effectively suppresses weeds. Juniper is also tough — it handles being buried by snowplow build-up, even with road salt! It’s a good choice for curb-side plantings and along sidewalks and driveways.

Creeping Juniper is attractive all winter along a property line

You can see another of our favorite evergreen groundcovers in the foundation planting at the Nature Center’s Manor House. Carex laxiculmis ‘Hobb,’ often sold as ‘Bunny Blue’ sedge, is a great groundcover for shade. It’s maybe more “everblue” than evergreen, so its eye-catching color is striking around and under shrubs, and even under shade trees. It will live happily with dense tree roots and spread itself slowly by short runners that sprout new little plants over time. It holds its blue-green strappy leaves all winter long. You don’t have to cut it back in the spring, but if it looks a bit ragged, you can trim the old leaves before new growth begins. Like most grasses and sedges, it is avoided by deer.

‘Bunny Blue’ sedge in winter under shrubs at the Manor House

Plant ‘Bunny Blue’ sedge with other native shade-lovers for a mix of textures. When the other plants go dormant in the fall, ‘Bunny Blue’ will hold the spot until they return

‘Bunny Blue’ sedge in summer in with Maidenhair Fern and Wild Canadian Ginger 

For a sunny area, we like Waldsteinia (or Geum) fragaroides, commonly called “Barren Strawberry” because its leaves look similar to strawberry, but it doesn’t bear fruit. Waldsteinia is a deer-resistant evergreen groundcover that likes sunny dry sites and blooms in early spring with bright yellow flowers. It only gets a few inches tall, so it’s great at the front of a flower bed. We planted it last year at the very front of the Nature Center’s new Pollinator Garden. Be sure to come see it bloom this spring!

Spring growth covers bronzed winter foliage of Waldsteinia

Waldsteinia spreads slowly by shallow runners. Use it around a mailbox or lamp post, or along a sunny path. Snow cover and freezing cold do not bother it, and it is hardy to Zone 4. Its leaves may turn bronze by late winter, but new growth will cover the old in spring and form a weed-suppressing mat. And when April showers bring May flowers, you’ll want to be there.

Waldsteinia blooms in late April to early May

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.