Cathy Ludden, Author at Nature Center at Greenburgh

February 10, 2022February 14, 2025 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.

February 3, 2022February 14, 2025 Cathy Ludden Around the Grounds, Native Plants

Oh, Say, Can You See…a White Pine?

Look out almost any window in suburban Westchester County, and chances are you can see an Eastern White Pine (Pinus strobus). This iconic evergreen is profoundly connected to the early history of the United States.

In 1605, English explorers sailing along the eastern coast of North America spied a solution to one of England’s most pressing problems: the lack of suitable trees for ships’ masts. Here, they saw seemingly infinite forests coming right up to the shoreline. And towering above the oaks, maples, beech, and birch trees were countless magnificent pines, so tall and straight that the explorers soon started calling them “mast trees.”

England’s power in the 17^th and 18^th centuries depended largely upon the British Royal Navy. Warships needed enormous wooden masts, at least 3 feet in diameter and over 100 feet tall. England had long since been cleared of trees that size, giving France, Spain, and the Dutch a critical advantage in shipbuilding. The Royal Navy was forced to negotiate with Norway and the Baltics for timber, but the biggest trees available were no more than 27 inches in diameter and not close to the necessary height. Masts had to be pieced together, creating vulnerabilities in bad weather and warfare.

The Eastern White Pine grows tall and straight, reaching 130 feet or more. It is strong, but able to bend without snapping in stormy winds. It drops its lower branches as it matures, creating a smooth expanse ready for milling. Whole forests made of enormous “mast trees” were a shipbuilder’s paradise, and the Eastern White Pine became a major factor in England’s decision to colonize North America.

White Pines tower over other forest trees

White Pines grow tall and straight with few lower branches

As colonists expanded settlements in Massachusetts, New Hampshire, and Maine, it didn’t take them long to recognize that Eastern White Pine was extremely useful for building everything. The Royal Navy wanted to protect its supply of mast trees, so England declared that all White Pines with a diameter of 24 inches or more were property of the King. Penalties were assessed for cutting the King’s pines, and fines were collected by surveyors appointed by the Crown — until one night in 1771 in Weare, New Hampshire.

Outraged at being fined for cutting trees on their own land, a group of “traitorous rebels,” colonists disguised with ash on their faces, dragged two British enforcement officers out of their beds, beat them with pine branch switches, tied them backwards onto their horses, and drove them out of town. It is thought that this act of rebellion, known as the “Pine Tree Riot,” was inspiration for the Boston Tea Party not long after. Both before and after the Revolution, White Pine was critical to the economy and development of America.

Today, this magnificent tree deserves our admiration for its beauty and its value to the ecosystem. Because of its vast height, it is a favorite nesting tree for bald eagles and hawks. Song birds, squirrels, and many other animals depend on the seeds in its pinecones. Its soft needles host the larvae of a dozen or more species of moths and butterflies.

White Pine cones are a valuable food source for wildlife

White Pine needles are fragrant, soft, and a host plant for butterflies and moths

As a landscape plant, Eastern White Pine is a gorgeous evergreen that smells divine and needs no special care. Though it is fast-growing, it can live to be hundreds of years old, so it needs some space. An arborist friend says White Pines are “self-pruning” because they drop branches as they mature. And those branches can be very heavy. It’s not a good idea to plant a White Pine too close to your house or other structures. Plant it where you can see its whole, unique shape from a window, and enjoy the fuzzy look of its needles.

It’s also not a good idea to plant White Pines as a property-line screen. It may be tempting to plant rows of young pines for that purpose, but remember — they grow up to be “mast trees!”

Beautiful, but not a good privacy screen!

The Eastern White Pine is an iconic plant with a fascinating history. We recommend a book, White Pine: American History and the Tree That Made a Nation by Andrew Vietze for more information. And we also recommend planting Eastern White Pine if you have the chance.

A baby White Pine at the edge of the Nature Center’s Meadow

January 27, 2022February 14, 2025 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.

January 20, 2022February 6, 2025 Cathy Ludden Around the Grounds, Native Plants

How Cold Is It Outside?

This week on our Around the Grounds blog, we monitor some plummeting temps to see how well our native Rhododendrons fare. How adaptable are they really? You might be surprised!

January 13, 2022February 14, 2025 Cathy Ludden Around the Grounds, Native Plants

Winter’s Green

Recently in Around the Grounds, we featured native shrubs that add splashes of color to the winter landscape. (Read our Winterberry and Red Osier Dogwood posts here.) While brilliant berries and colorful bark are important for winter interest, evergreen shrubs are the backbone of the garden, providing structure throughout the year. And, as we remind ourselves, green is a color, too!

Unfortunately, our suburban landscapes tend to use a very limited repertoire of evergreen plants. We think there are better and more interesting choices than boxwood and taxus for residential foundation plantings. Take a look at some of the evergreens we’ve used at the Nature Center:

Inkberry shrubs define the edge of our patio garden all year

One of our favorites is the native Inkberry (Ilex glabra). Inkberry resembles boxwood, with similar dark green, shiny leaves. And, like boxwood, it can be pruned into a hedge, or a sphere, or any shape Edward Scissorhands might fancy. We prefer to let it take a natural, rounded shape with dense branches as hiding places for songbirds.

Inkberry looks similar to boxwood or Japanese holly, but is hardier

Unlike boxwood, Inkberry is adapted to our climate because it is native here. Boxwood originated in southern Europe, northern Africa, and western Asia; all climates very different from ours. Gardeners here are advised to wrap boxwood with burlap in winter to protect it from cold, wind, and salt – not a great look for “winter interest.”

Unlike Inkberry, boxwood needs protection from winter weather

Inkberry is not only cold-tolerant, even to temps below zero, but it enjoys our acidic soil and doesn’t mind sitting in water after heavy rainfalls. It is deer-resistant and salt-tolerant. It does prefer full sun, but can handle some shade. The straight species will get 6 to 8 feet tall, but it can be sheared and shorter cultivars are available.

We’re not sure why so many suburban dwellers like plants pruned into ball shapes, but we do know a native evergreen that will take that shape without any help! Growers have developed cultivars of our native Arborvitae that grow naturally into a ball shape without pruning.

Globe Arborvitae grows in a spherical shape

Arborvitae (Thuja occidentalis), also known as Eastern or Northern White Cedar, is very familiar as a tree; often used as a hedge or screen. It is native to our region and has wildlife value as a nesting site and seed supply for birds. Be advised that it is also famously attractive to deer. Some sellers of Globe Arborvitae claim the shrub is more deer-resistant than the tree, but we planted it close to a busy patio just in case. There are numerous cultivars of Globe Arborvitae available, with varying maximum sizes and slight color variations. Because we always prefer native plants, we would choose this little shrub over either boxwood or taxus – and we don’t have to prune it!

On our patio, Globe Arborvitae echos the rounded form of Inkberry

Another delightful evergreen shrub developed from a native tree is Pinus strobus ‘Soft Touch’ or Dwarf Eastern White Pine. ‘Soft Touch’ makes a great foundation plant. It is slow-growing, eventually taking a flattened shape no more than 2 feet tall, and wider than it is tall. It stays a lovely bright green all winter long. Its needles really are soft to the touch, and it’s hard to resist giving it a pat every now and then.

Dwarf White Pine ‘Soft Touch’ at the Manor House foundation

At the entrance to the Nature Center, we use another dwarf evergreen as a container plant. Dwarf Alberta Spruce (Picea glauca ‘Conica’) also was developed from a very large native tree, the White Spruce. This dwarf variety is very slow-growing and maintains its classic Christmas tree shape without pruning. It can live for years in containers, but should eventually be given some space in the landscape. It can become a 10-13 foot tree in time, so we will have to turn ours loose on the grounds in a few more years.