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March 14, 2024February 12, 2025 Cathy Ludden Around the Grounds, Native Plants

What NOT to Plant

Spring is approaching! Garden and seed catalogues are arriving in the mail. Nurseries and big box stores will soon begin displaying thousands of plants for our home gardens.

As we plan to beautify our yards, it’s easy to be seduced by photos of gorgeous flowers and promises of carefree shrubs. But beware: many of these plants are not as advertised! It pays for avoid common mistakes now to prevent later problems that can cost you dearly.

The biggest mistake, both for nature and your wallet, is buying invasive plants. And it’s too easy to do! Many of the most common and familiar yard plants are actually invasive species. And most of them are still being sold across the country every day!

Garden catalogue offering an invasive shrub actually prohibited in several states.

English ivy costs American homeowners millions of dollars in tree and building damage every year, but is still sold legally in every state but Oregon.

The term “invasive” applies to plants from other continents that have no natural controls in North America (nothing here eats them!), and they are so successful at reproducing themselves that they spread unchecked causing environmental and economic harm. Invasive plants cost the US – individual property owners, corporations, non-profits, and all levels of government combined – an estimated $142 billion annually! Because invasive plants out-compete native plants, they take over forests, grasslands, wetlands, roadsides, parks, and residential areas, eliminating food and other resources for wildlife, as well as pulling down power lines, trees, fences, and damaging building siding and exterior finishes. Fighting invasive plants is frustrating and very expensive.

IMG_2762-3 — Invasive vines choke native trees on America’s roadsides.

IMG_2801-1 — Invasive landscape plants like Japanese pachysandra take over parks and wooded areas and are difficult to remove.

There are at least 5000 plant species currently identified as invasive in the US, and over 2/3 of them were introduced to this continent not for food, medicine, or commercial value, but simply because somebody thought they made pretty garden plants. Many states, including New York, have begun to regulate the sale or marketing of a few species of invasive plants. But the power of the nursery industry, and the popularity of many invasive plants with gardeners, has prevented more effective legal controls. Nurseries and mail-order houses still sell hundreds of invasive species. In fact, the nursery industry is the primary pathway for invasive plant introduction. Ultimately, though, it’s up to homeowners and gardeners to refuse to buy these plants.

So, how do we know which plants are invasive and should be avoided?

The simplest way is to use your phone! Put the name of the plant you’re considering and the word “invasive” into Google, or whatever search engine you use, and see what happens! For example, this is the result of a .32-second search using the words “pachysandra” and “invasive”:

Seeing that result should suggest choosing a different groundcover – a native one, perhaps?

Another way to avoid invasive plants is to watch for certain buzzwords in the ads. Like most businesses, the nursery industry grabs consumer attention with ads emphasizing the benefits of a product while omitting any discussion of the down-side. As you browse catalogues and nursery labels, watch for the red flags that signal invasive plant characteristics. Words like “grows anywhere,” “fast-spreading,” and “pest free” can mean that a plant has no natural insect or animal controls on this continent.

Catalogue offer using almost all the buzzwords.

This is a great example: any plant that will grow on “steep slopes, poor soil, trouble areas, stream or pond banks,” yet is “drought resistant and sub-zero hardy,” as well as “disease and insect free” and “grows so thick it chokes out even persistent weeds and requires no mowing or care” is the very definition of an invasive species!!

A quick Google search instantly turns up the truth about the advertised plant:

A search for “crown vetch invasive” immediately hits Invasive.org and state governments reporting the invasive plant.

At the bottom of the catalogue ad for crown vetch, there is a note that it cannot be shipped to certain states. That is another dead give-away. If any state has actually prohibited importation of the plant, it is extremely likely that the plant is invasive in many other areas as well. The political process just hasn’t progressed far enough to actually outlaw the plant in other states. Checking Invasive.org will tell the true story:

Invasive.org is a joint project of the University of Georgia and the US Department of Agriculture. They collect, review, monitor, and aggregate reports of invasive plant species that have escaped cultivation and infested natural areas. If a plant is reported as invasive anywhere in the US, it is best simply to avoid it and choose something else, preferably a native plant.

Of course, the best reason to avoid planting invasive species is to protect natural areas and critical habitat for American wildlife. But protecting the value of your own property, and sparing yourself the misery of trying to get rid of a plant you wish you had never planted, is another good reason.

If you fell for an ad like this:

Catalogue ad for *Aegopodium*, also known as bishop’s weed, or goutweed.

and then watched in horror as that “snowy” plant turned into a solid green mass, invading your lawn and every flower bed, you understand the meaning of regret. (We hear there is a “support group” on Facebook for people who have been victimized by goutweed!)

Other commonly sold plants that can become big regrets on suburban properties include: bamboo, Chinese wisteria, wintercreeper, Asian honeysuckle, periwinkle (vinca), Chinese silver grass, Rose of Sharon, ajuga (bugleweed), Norway maple, and of course, all forms of ivy. All of these plants can spread themselves well beyond where you wanted them and are tough to remove, creating maintenance headaches.

Still other invasive species may not cause trouble in your yard, but will find their way into nearby woods, parks, and natural areas: burning bush, privet, Japanese barberry, autumn olive, buckthorn, Bradford pear, tree of heaven, and Japanese spirea all spread themselves aggressively from gardens into natural areas.

There are so many excellent native alternatives to these troublemakers. Native plants do have natural controls! Birds, bees, insects, and other animals not only need native plants, their participation in the ecosystem will save you the expense and effort of battling invasive plants. Look back through the Around the Grounds Collection for lots of native plant recommendations that will work in your yard.

Happy spring gardening!

THIS BLOG IS WRITTEN 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 15, 2024February 12, 2025 Cathy Ludden Around the Grounds, Native Plants

Soggy Solutions

Do you have a soggy situation in your yard: a low spot where water always puddles for a few days before drying up? If so, lucky you! You’ve got the perfect spot for some beautiful water-loving shrubs!

Rainstorms are becoming more frequent and more intense. Suburban lawns often have mushy patches that don’t really recover, even after the ground dries. Turf grass roots sitting in standing water are deprived of oxygen and soon die. You could spend hours – and dollars — aerating, re-seeding, or laying new sod only to see the same thing happen again in the next downpour.

Lawn grass can’t live in water-logged soil

Or, you could plant a few native shrubs that would be happy to soak up that water! Some of our most desirable native plants evolved near ponds, streams, and in wet meadows. They can live in standing water for days at a time, and take up excess water that otherwise becomes mosquito-breeding habitat. Even better, because they are native to our region, they are winter-hardy and provide food for pollinators and birds.

It’s not hard to remedy a soggy area of lawn. You can plant right into the wet areas, even without removing any surviving lawn first. With the right plants, not much soil amendment is necessary, either. Dig a hole about the same depth and twice the circumference of the root ball of the shrub. Loosen the root ball if it is very tightly bound. Adding a few shovel fulls of compost and mixing it with the soil in the planting hole can help. But don’t plant too deep. Keep the crown of the plant just above the soil line. And give your new plant some company! More plants take up more water, reduce compaction, and improve soil drainage, which improves survival odds for all of the plants.

Visually, a cluster of water-loving shrubs is a big improvement over soggy lawn. Think about planting a group of 3 medium-sized shrubs, either all the same type or 3 different species, or perhaps a small tree and a couple of larger shrubs. A group of plants looks more natural, takes up more water, and provides valuable habitat for birds.

Assuming the spot is mostly sunny, and usually dries out a few days after a rainstorm, any of these great shrubs will work beautifully:

Buttonbush (Cephalanthus occidentalis)
Buttonbush produces really interesting flowers from early to mid-summer that last for weeks. The flowers look like 1½-inch white spheres and attract hummingbirds and butterflies. The leaves are large, glossy green, and make a gorgeous background for the flowers. After the flowers fade, hard spherical nuts resembling buttons develop and often last through the winter until birds harvest them.

Buttonbush flowers
*Photo: Lady Bird Johnson Wildflower Center*

Native to swamps and streamsides from Canada to Florida and west to the Mississippi River, Buttonbush is hardy in Zones 4 to 10. In the Northeast, the shrub can reach 6 to 12 feet tall and 4 to 8 feet wide. In colder zones, the shrub may die back to the ground in winter and grow back to 3 to 4 feet in summer. Pruning is not necessary, but if you want to keep it a bit smaller, it won’t mind being pruned in early spring since the flowers form on new growth.

Buttonbush becomes a large rounded shrub in suburban landscapes
*Photo: American Beauties Native Plants*

Buttonbush loves wet soil, including areas that are often flooded with shallow standing water. It is generally deer-resistant once established, but young plants should be protected in the first few years. The shrub is happy in full sun or part shade.

Possumhaw viburnum (Viburnum nudum)
Also called Smooth Witherod, this shrub is one of our most attractive native plants for suburban landscapes. It will tolerate wet, boggy soil, though it does perfectly well in average soil as well, and is a great foundation plant. Native to woodlands, swamps, and thickets from Newfoundland to Florida, it grows 6 to 12 feet tall and 4 to 15 feet wide. It has shiny green leaves, big lacy white flowers in spring, and berries that turn colors from pink to blue to black. It also has spectacular fall leaf color. Possumhaw doesn’t need pruning and is not particularly attractive to deer. This plant works in almost any yard, but it is an ideal solution for a wet area.

*Viburnum nudum* as a foundation plant at the Nature Center

Possumhaw berries change colors as
they ripen

Winterberry (Ilex verticillata)
It’s hard to imagine a more useful landscape plant than Winterberry. It can live in standing water, but is also fine in average landscape conditions. It produces brilliant red berries in the fall that feed migrating birds.

Robins, mockingbirds, blue jays, cardinals, and cedar
waxwings flock to Winterberries

Winterberry is very easy to grow in full sun or part shade. It needs no fertilizer or special care, and needs no pruning. The shrub has a loose shape and can grow 10 to 15 feet tall, but a cultivar called ‘Winter Sprite’ tops out at 3 to 4 feet. In fall, the leaves drop to show the brilliant red berries clustered along the stems. You will need both a male and female plant to produce berries, so ask your nursery for both. For more information on Winterberry, see an earlier post here.

Pussy Willow (Salix discolor).
Willows are wetland plants, and our native Pussy Willow is the most beloved of the bunch. As a multi-trunked shrub or small tree, 6 to 15 feet tall, Pussy Willow makes a great focal point where water collects. Plant it, then add two or three of the shrubs described above, and a formerly soggy mess will become your favorite part of the yard! For more information on this great little tree, read our earlier blog post here.

Pussy Willow (*Salix discolor*) is an easy-to-love small tree

Fuzzy catkins show up in early spring and feed emerging pollinators

So, as you start dreaming about spring flowers, don’t forget about spring “showers,” which are more likely to be torrential downpours these days. Plan ahead for standing water and add some of these water-loving plants to your spring shopping list!

December 6, 2023February 12, 2025 Cathy Ludden Around the Grounds, Native Plants

Mighty Arborvitae

Arborvitae gets no respect.

Though Arborvitae (Thuja occidentalis) may be the most-planted tree in suburban America, it has been given a diminished role unworthy of this majestic native tree. Planted by the thousands along property lines by developers, builders, and landscapers, rows of crowded Arborvitae trees, standing shoulder to shoulder, have become the de-facto fences of suburbia.

A typical builder installation of Arborvitae

Without room to spread their branches or reach their natural height, Arborvitae is often topped and heavily pruned to form hedges. They handle this assignment very well, but Arborvitae can do so much more!

If you’ve only seen Arborvitae used as a hedge, it may surprise you to learn that in its natural habitat, it can grow 50 to 60 feet tall and live for hundreds of years! In fact, the largest known specimen is over 100 feet tall and more than 40 feet wide at the crown. The oldest living Arborvitae is thought to have germinated from seed in 952 A.D., and is now 1,071 years old! Based on ring counts on dead trees, there are verified specimens of Arborvitae that lived to be over 1,800 years old.

An ancient stand of Arborvitae on cliffs overlooking
Northern Lake Michigan
*Photo: C.J. Earle*

Arborvitae is one of the common names for Thuja occidentalis and means “tree of life” in Latin. It was named by the French sea captain, Jacques Cartier, when he was exploring Canada in 1536. After months at sea, Cartier’s crew, including two young members of the Huron native tribe who had been sailing with them, were all suffering from scurvy. On the way up the St. Lawrence River, Cartier dropped the two young men at their home village. When he later returned, he was astonished to find the two Hurons fully recovered from all symptoms of scurvy while his French sailors were still suffering. He asked the Huron elders to teach him the cure, and they showed him how to make a medicine, a tea rich in Vitamin C, from the foliage of Thuja occidentalis. Cartier brought the life-saving plant back to France, making it the first North American tree introduced to Europe.

The native habitat of Thuja occidentalis is swamps, low woods, and forest edges from northern Canada south to New York and Connecticut and west to Michigan and Northern Indiana. It is an evergreen conifer, extremely cold hardy, and adapted to poor rocky soils all the way to the edge of the Canadian tundra. Sometimes called Northern White Cedar, Eastern White Cedar, or Swamp Cedar, Arborvitae is not a true cedar in the Cedrus family, none of which are native to North America. But the fragrance of its foliage and bark, and the usefulness of its wood, are similar.

Arborvitae often grows in very thin, poor soil in northern
North America and is adapted to extreme cold. This forest of
Arborvitae is at the brink of the Niagara Escarpment in Northern Wisconsin.
*Photo: C.J. Earle*

The foliage of Arborvitae is flat and scale-like and has a spicy fragrance when crushed. Native peoples used it not only for medicine but also used the fragrant foliage as insect-repellant bedding. They stripped the tree’s shredding bark to make rope and twine, and they found many uses for the rot-resistant wood, including canoe frames and roofing shingles.

Thuja occidentalis has significant value to wildlife. It is a favorite food of white-tailed deer, as suburban homeowners often discover to their dismay. Twigs and foliage of Arborvitae constitute as much as 10 to 25% of the winter diet of deer, who will browse it as high as they can reach. In northern forests, the tree also provides highly nutritious food for snowshoe hares, porcupines, red squirrels, and beavers. Many native birds find nesting sites in Arborvitae and insects to feed their young. The seeds are the preferred source of food for Pine Siskins, birds indigenous to the Northeastern US.

It is sadly ironic that one of the most-planted trees in suburbia is disappearing in the wild. Thuja occidentalis is listed as Threatened in Connecticut, Illinois, Kentucky, and Maryland and Endangered in Indiana, Massachusetts, and New Jersey. Development is the primary culprit as forests are cleared to make way for more suburban homes.

It is equally sad that the rows and rows of Arborvitae planted on suburban property lines are not nearly as valuable to wildlife as they should be. The most popular varieties of Arborvitae are cultivars or hybrids that offer little value to wildlife – other than deer. A cultivar called ‘Emerald Green’ Arborvitae was developed in the 1950s in Denmark, just in time for the rapid expansion of the US suburbs after WWII. It quickly became the ubiquitous hedge plant we see all around us. In a tight hedge, and with limited biological diversity due to clonal reproduction by nurseries, its value to insects and birds is limited.

Another Arborvitae popular with builders is a hybrid called ‘Green Giant,’ which is a cross between a species indigenous to the Pacific Northwest and a Japanese species. As a hybrid between two non-natives, ‘Green Giant’ has very little value to insects or birds in this part of the country. If you can find the straight species of Thuja occidentalis (without a cultivar name), plant that. If not, ‘Emerald Green’ is a better choice than ‘Green Giant.’

Thuja occidentalis is an amazing tree. It deserves to be more than a fence! Given enough room to take its natural form, Arborvitae merits a starring role in suburban landscapes.

Growing the way nature intended, Arborvitae takes its
rightful place with Oaks, White Pines, and Junipers in
Northeastern landscapes

In our last blog post [Privacy Without “O-fence“], we urged homeowners to diversify their hedges and privacy screens by planting a mix of native trees and shrubs to increase habitat and biodiversity. Too much of any one plant becomes a mono-culture, limiting resources for wildlife. Unfortunately, that is what has happened to this magnificent native tree.

Don’t limit Arborvitae to this poor fate

Think of Arborvitae as an easy-care, long-lived, medium-sized, native, hardy evergreen that will enhance your landscape as part of a diverse planting of trees, shrubs, and perennials. You won’t be sorry!

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.

November 15, 2023February 12, 2025 Cathy Ludden Around the Grounds, Invasives, Native Plants, Pollinators

Privacy Without “O-fence”

Suburban yards are places for families and friends to relax, perhaps enjoy a barbecue, and watch children and pets play safely. Privacy is important.

No wonder, then, that suburban homeowners often decide to plant a “privacy screen.” Hedges of trees or shrubs, planted as living “green fences,” are as common in suburbia as the lawns they typically surround.

But too often, these hedges are made with invasive plants that spread themselves into natural areas causing ecological harm. Top offenders include privet, Japanese barberry, forsythia, bamboo, and burning bush. All of these plants are recognized as invasive species and should be avoided.

Forsythia is not a good choice for a privacy screen

Burning Bush — Burning bush may look good for a minute

Japanese barberry, now banned in several states, spreads by seed into vacant lots, woods, and roadsides and actually increases the population of ticks carrying Lyme disease!

The good news is that the need for privacy does not require bringing any of these offensive plants onto your property. There are so many better choices!

In the Eastern US, the most popular privacy screen by far is Arborvitae (Thuja occidentalis), also known as Northern White-cedar. Favored by builders and landscape maintenance companies, a row of inexpensive and readily available Arborvitae is often planted along the property line as soon as a new house is built.

Though Arborvitae is a much better choice than any of the invasive plants mentioned above, it is not the only — or best — option. In areas populated by deer, Arborvitae is extremely vulnerable.

Here are some alternatives – beautiful evergreen trees and shrubs, native to the Northeast, that make ideal privacy screens. And because they are native, they also offer value to native birds and pollinators!

American Holly (Ilex opaca) makes a dense, evergreen privacy screen and has the bonus of tiny flowers for pollinators in the spring and beautiful berries that add winter interest to the landscape.

American Holly may be pruned into a hedge

Rhododendron is another good choice for privacy. When European settlers first explored the Eastern US, they struggled through massive stands of Rhododendron maximum that formed impenetrable evergreen thickets. Why not use that same feature now as an effective screen? Our native songbirds love to hide in a thicket!

Inkberry (Ilex glauca), another native evergreen, grows quickly and has shiny, dark green leaves that form a dense screen. More winter-hardy than boxwood and growing taller, Inkberry is a great hedge plant.

Red Twig Dogwood and Switch Grass — Inkberry in a mixed border with Red Twig Dogwood and Switch
Grass

The very best privacy screen, though, is not a row of one species of plant, but a forest! The Northeastern US was once predominantly forest, and many of the plants in those forests are still the best plants to grow here. In suburban yards, we can mimic the beauty, seclusion, and peaceful quiet of a diverse forest simply by planting more stuff! And a bigger variety of that stuff is inspired by our native forests!

Maybe it’s time to reconsider our approach to the “privacy screen.”

Hedges can be great, but they can also be visually boring and ecologically sterile. There is no law requiring homeowners to mark their property boundaries with a row of identical plants. Just because your property line forms a rectangle doesn’t mean your landscape has to be one. A diverse mix of plants – native trees, shrubs, grasses, and perennials – planted in masses makes a landscape interesting, lush, ecologically valuable, and very private.

Contrasting approaches – the mixed border of deciduous and evergreen trees on the right offers more interest, and more privacy, than the hedge on the left

white pine, arborvitae, spruce, juniper, and Rhododendron — A mix of White Pine, Arborvitae, Spruce, Juniper, and
Rhododendron completely screens a house from the road

If you already have a hedge or a fence along the property line, consider planting inside it using a mix of native trees and shrubs that change with the seasons. Start with the corners.

Trained landscape designers tend to avoid square corners and straight lines in their designed plantings. You can do the same thing. Map out curved beds that soften the corners and bring more plants further into your yard. Plant taller shrubs at the back, and choose flowering shrubs and perennials to plant in the foreground where you can enjoy them.

Fences along two neighboring properties meet to form a hard corner that is softened, and completely screened, by a curved planting of mixed trees, shrubs, and perennials

So, consider creating a privacy screen that looks more like a forest than a fence. By planting more plants, and a bigger variety of plants in more of your yard, you will have more privacy, more seasonal interest, less lawn to tend, and more habitat for birds, butterflies, and fireflies.

How’s that for a win-win-win-win?!

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.

November 2, 2023February 12, 2025 Cathy Ludden Around the Grounds

Autumn Wonderland

The Northeastern United States is famous for fall foliage. “Leaf peepers” come from all over the world to see our native plants in their dramatic fall colors.

Why, then, should a walk around suburban neighborhoods, in the same region during the same season, be so disappointing? Where are the colors?

The plants that thrill “leaf peepers” grew in abundance before the suburbs were developed, and they would still thrive here – if only they were planted! It seems that every suburban yard uses the same non-native “foundation plants” — boxwood, pachysandra, ivy, and hedges of yew or privet or even bamboo! – all completely devoid of our famous fall colors!

C’mon people! We can do so much better than this! Why not plant our yards with the same trees, shrubs, and perennials that make this region a tourist attraction in the fall? Let’s add some color, life, and seasonal interest beyond pumpkins! There are so many great choices with our incredible abundance of Northeastern native plants.

Red maple (*Acer rubrum*)
Photo: Michael Martini

The undisputed rock-stars of fall color are our native Maples, and Oak trees are a close second. If you have a lawn, you probably have room for a Maple or a native Oak. Oaks have enormous value for wildlife — and for homeowners! [See this blog post] Both Maples and Oaks are beautiful year-round, but autumn is their glory season.

Our native flowering trees are also brilliant in the fall. Nothing beats the American Dogwood (Cornus florida) with its intense maroon foliage and vivid scarlet berries. Crabapples (Malus spp.) also produce colorful fruit, and American Witch Hazel (Hamamelis virginiana) starts blooming in October!

The Northeast is also blessed with native shrubs that produce kaleidoscopic colors in the fall. While evergreen foundation shrubs are useful, why not add some of the flowering and fruiting native shrubs that bring color and interest in both spring and fall? Here are some easy choices to add to your yard. All of the shrubs pictured below are locally available, easy to grow, valuable to wildlife, have beautiful flowers, and are spectacular in the fall.

Oakleaf Hydrangea (*Hydrangea quercifolia*)

Possumhaw Viburum (*Viburnum nudum*) pictured with
American Witch Hazel

Low Bush Blueberry (*Vaccinium angustifolium*)

American Cranberrybush (*Viburnum trilobum*)

And don’t forget fall flowers and grasses in gorgeous colors!

Aromatic Aster (*Symphyotrichum oblongifolium* ‘Raydon’s Favorite’)

Switch Grass (*Panicum virgatum* ‘Cheyenne Sky’) shown with Ironweed (*Vernonia lettermanii* ‘Iron Butterfly’)

Not only are these plants beautiful, they are incredibly valuable to the ecosystem of the Northeastern US. So many suburban landscapes use non-native plants that offer nothing to birds, butterflies, bees and other insects, and many are destructively invasive as well. If your only fall color is coming from burning bush or Japanese maple, you may want to consider native alternatives for those reasons. Privet, bamboo, ivy, vinca, and pachysandra are all known to be invasive plants and can be replaced easily with native plants that are beautiful in the fall, and year-round.

And wouldn’t you enjoy an autumn view like this?