native plants Archives - Page 10 of 14 - Nature Center at Greenburgh

March 31, 2022February 14, 2025 Cathy Ludden Around the Grounds, Native Plants

Marvelous Milkweed – Not Just for Monarchs!

Last week in Around the Grounds we joined the happy buzz about pollinator gardens springing up everywhere. We know that bees need native flowers for nectar and pollen. Butterflies also need nectar, and they need the host plants their caterpillars eat. So, a good pollinator garden supplies all three resources – nectar, pollen, and host plants. Planting a big variety of native plants is the best way to do that.

However, there are a few special plants that do all three jobs. Top among them is Milkweed (Asclepias spp.). Milkweed, of course, is the only host plant for Monarch butterflies.

If you go looking for monarch caterpillars on Milkweed, you may discover an entire, complex ecosystem. A research study in Ohio documented 457 different insect species on just one stand of Milkweed! That’s a lot of biodiversity supported by this amazing plant.

In addition to monarchs, Milkweed is the host plant for 11 other species of Lepidoptera (the insect family for moths and butterflies). One of them is the Milkweed tussock moth. Many a gardener has been shocked to discover a mass of little wriggling black caterpillars rapidly devouring their prized Milkweed plants. But before you panic, consider the careful balance nature has designed.

The Milkweed tussock moth arrives later in the season, after most of the Monarch caterpillars already have eaten their fill and turned into butterflies, so there is plenty of Milkweed for everybody. As these little black caterpillars mature, they wander away from the pack and grow from creepy to… sort of cute? But don’t touch them without gloves. Those funny hairs can sting like nettles.

Milkweed tussock moths are important night-pollinators, and their main predator is bats. Astonishingly, they have developed a defensive sonar-type beep that warns bats away from them.

**Milkweed tussock moth caterpillar**
Photo: M.J. Raupp

Another common sight on Milkweed is a large population of Milkweed aphids. You could hose them off, or squish them with your fingers. Or, you could just watch as ladybugs show up to feed on them. Ladybugs are very effective insect-eaters. One ladybug can eat up to 50 aphids a day. Lacewings, tiny parasitic wasps, and several other beneficial insects also are likely to join the aphid hunt, so the aphid situation seems to take care of itself in our garden.

We’ve found walking sticks, praying mantids, ants, bees, flies, wasps, spiders, and specialized Milkweed bugs and beetles, all living their best lives on Milkweed.

**You never know what you’ll find on the underside of Milkweed leaves**

A spider sets up shop to see
what will wander in

**Milkweed bugs eat the seeds in late summer and fall**
Photo: Travis Brady

Oh! Did we mention butterflies? Milkweed is loaded with nectar and draws ALL the butterflies – not just Monarchs.

**Spicebush swallowtails in mating dance on Milkweed**

While the best Milkweed for supporting all of this life is probably Common Milkweed (Asclepias syriaca), that species is rather big, coarse, and an aggressive spreader for smaller gardens. Sadly, it’s the loss of Common Milkweed from roadsides, farmyards, and wild places all the way from Mexico to Canada that has caused the tragic decline of monarch populations.

But gardeners are making a difference, and with beautiful Milkweed species for smaller gardens, it’s really easy to do. Swamp Milkweed (Asclepias incarnata) grows 3 – 4 feet tall and blooms for months. Its lavender-pink flowers blend in with lots of other sun-loving perennials. It is perfect for pollinator gardens, meadows, and mixed borders. And it also comes in white!

**Swamp Milkweed (*Asclepias incarnata*) is a butterfly magnet**

Every garden can find a place for Butterfly Weed (Asclepias tuberosa). This lovely Milkweed is a perfect front-the-border plant. It grows about 2 feet tall and is fairly compact. It stays where you plant it and is reliably hardy. The straight species is a sunny orange, and there is a bright yellow cultivar called ‘Hello Yellow.’ Butterfly Weed does best in full sun and well-drained soil. It rarely needs supplemental water, and never needs fertilizer.

**Butterfly weed (*Asclepias tuberosa*) at the Nature Center**

Whether or not you are planning a pollinator garden, if you love nature, be sure to add marvelous Milkweed to your spring planting list.

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.

March 24, 2022February 14, 2025 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?

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!

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.

March 17, 2022February 14, 2025 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 16^th 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.

March 3, 2022February 18, 2025 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

February 17, 2022February 14, 2025 Cathy Ludden Around the Grounds, Invasives

Evil Ivy Over Everything

We have a big problem at the Nature Center. And we are not alone.

Ivy (Hedera spp.) – English Ivy, Irish Ivy, Persian Ivy – causes enormous damage to trees, buildings, and forest ecology throughout the United States. Maybe you’ve already seen Ivy pull stucco, mortar, trellises, and rain gutters off of buildings, or cause wooden siding to rot or attract mold. At least those things can be repaired.

The damage Ivy causes in nature is much worse. It climbs trees, slowly strangling them to death by stealing light and water, and it weighs down their weakened branches until they break and fall during storms. It crawls across the ground, sending out roots to take up all available nutrition. And it smothers the ground with its evergreen leaves so other plants cannot establish or find enough light to survive.

Ivy chokes trees by stealing light, air, and water

The weight of ivy breaks trees already weakened by choking vines

Forests in our region were once populated with hundreds of different species of shade-loving plants: ferns, grasses, and a huge variety of wildflowers. Those plants fed thousands of species of insects, birds, and animals. Of course, development and too many deer have contributed to a tragic loss of these species, and so has the introduction of invasive plants. Ivy is one of the worst offenders.

A healthy forest is filled with great diversity of plants

Ivy eliminates other species on the forest floor

There is nothing wrong with English Ivy — in England! It doesn’t overrun woodlands in Europe because it evolved there, and European insects and animals eat Ivy and control its growth.

In America, there are no natural controls, no insects or other animals to keep it in check, so Ivy becomes invasive. It out-competes native plants, leaving the forest depleted and sterile. Nothing here eats Ivy, so when Ivy is all that is left in the forest, there is nothing for forest animals to eat.

Some birds eat berries produced by Ivy and scatter the seeds, which can spread Ivy from garden to forest. But humans are much more culpable. Ivy is unfortunately popular with humans because it is evergreen, grows very fast, will live in sun or shade, and can cover a lot of ground or a wall very quickly. But it is also very difficult to control once it is established. Cutting vines at the base, applying herbicide to cut stems, and digging out roots can help save trees, but diligence is required to prevent this very aggressive pest from trying again.

There is no true Ivy native to North America. But there is a beautiful native plant that makes a great substitute for Ivy. If you want a climbing vine to cover a wall or an arbor, or you’re looking for a groundcover for a shady area, try Virginia Creeper (Parthenocissus quinquefolia). It is fast growing, and it has glorious fall color. Its leaves are the host plant for the very interesting Sphinx moth – the native insect that acts as a natural control preventing this vine from taking over the forest. Virginia Creeper will wind its way up a tree trunk, but it won’t kill your trees.

Virginia creeper evolved here, and belongs in our woods – *photo courtesy of pixabay.com*

Don’t be confused by the common names of Boston Ivy (Parthenocissus tricuspidata) and Poison Ivy (Toxicodendron radicans). Boston ivy is not from Boston and it’s not an Ivy. It is an Asian vine in the same family as Virginia Creeper. Though it is not as destructive as Ivy, it actually can grow faster and taller than Ivy and completely cover a building in no time. Poison Ivy is not an Ivy either. It is a native vine and, interestingly, it is only “poison” to allergic humans and not at all to other animals. It actually has a lot of wildlife value to birds and other animals. If it’s not in your immediate area, you could consider admiring its beautiful fall color from afar!

In the coming years, the Nature Center has a fight on its hands. We want to remove Ivy from our 33 acres of woods. While some areas are only partially affected, and we work hard to keep Ivy off of our trees, there are large sections of our forest totally overrun with Ivy. We will be formulating plans for an Ivy-removal program this year, but it will be difficult and expensive. If you would like to help by making a contribution, please visit our Donate page here.