Category: Around the Grounds

Featured photo by Alix Dunn

Evergreens are an important part of residential landscapes. They offer year-round structure, winter interest, and habitat for winter birds and animals.

In the Northeastern US, we are fortunate to have a great variety of excellent native evergreens to choose from. Long before European settlers arrived, native evergreens — trees, shrubs, perennials, and groundcovers — populated Northeastern forests, open meadows, and rocky coastlines, supplying local wildlife with food and shelter through long, cold winters.

So, why are modern suburban landscapes in the Northeast dominated by non-native evergreens?

English and Asian boxwoods, European hollies, and many Asian azaleas need special winter protection from snow and ice, dry winds, and salt. These plants are not well-adapted to winters in the Northern parts of the US because they evolved on continents with milder winters and very different soil chemistry. So, if we plant these non-native plants, we are advised to wrap them in unattractive burlap bags all winter, or expect dead patches of winter-burn and salt damage in the spring.

Native junipers, on the other hand, need no coddling.

Creeping Juniper
Juniperus horizontalis or Creeping Juniper evolved growing on rocky, wind-swept cliffs from the Yukon Territory across Canada to Newfoundland and from Montana through New York and New England. It makes sense that a plant that evolved in the glacier-scarred North does not need to be swaddled in burlap to survive our modern winters! Yet, Creeping Juniper is so tough that today it also survives surrounded by asphalt in parking lots and traffic circles in Florida!

Creeping Juniper is a conifer that makes an outstanding evergreen groundcover in suburban landscapes. It grows close to the ground, typically staying under 18 inches in height but will gradually spread its long horizontal branches out 5 to 8 feet wide. Like most evergreens, it prefers full sun, but it is not at all fussy about soil, does not need fertilizer, and is extraordinarily drought tolerant. It is also salt-tolerant, and doesn’t mind being buried by snow, so it is a great choice for edging roadsides, driveways, and walkways. It also works well to stabilize slopes and prevent erosion.

Deer, rabbits, and woodchucks usually ignore Creeping Juniper. Its aromatic foliage includes both scale-like leaves and spiky awl-shaped leaves that seem to discourage nibbling. But, much like the greatest American juniper, Eastern Red-cedar discussed in our last post here, the “berries,” which are really cones produced by female plants, are prized by native birds. Cedar waxwings, robins, blue jays, flickers, catbirds, and chipping sparrows all are attracted to the tasty berries.

Unfortunately, the junipers most commonly offered for sale in the nursery trade are not native to the US, but are from Asia. Juniperus chinensis, Juniperus japonica, and their many cultivars are neither more attractive than our native junipers, nor as hardy, and are definitely less appreciated by birds. Though birds will eat berries from the Asian species, studies have shown that native birds have a definite preference for native juniper berries.

So, look for shrubs labelled Juniperus horizontalis, Juniperus virginiana, or Juniperus communis (discussed below) as you shop for evergreens. There are loads of attractive cultivars of each of these native plants that are at least as appealing the cultivars of non-native junipers.

Juniperus horizontalis ‘Wiltonii’ (pictured above), often called ‘Blue Rug’ Juniper, stays very low at about 4 inches in height. It makes a great groundcover and looks fabulous draping over a garden wall. Juniperus horizontalis ‘Bar Harbor’ is fast-growing and stays low, but will spread up to 10 feet wide with blue-gray foliage that turns purplish in winter. ‘Gold Strike’ has light green to gold foliage and mounds up a bit taller. All of them are incredibly durable and care-free garden shrubs.

Common Juniper
And then there is the most wide-spread evergreen conifer in the world: Juniperus communis or Common Juniper. It is native not only to the Northeastern US, but throughout the Northern Hemisphere all around the planet! Its native habitats range from European coniferous forests and alpine open areas, to the northern parts of Eurasia, including Siberia and Mongolia, and even within the Arctic Circle. In the US, it is found from Alaska to New England and from the Rocky Mountains south to Arizona and across the country to Kentucky and the Carolinas.

Its form around the world varies from medium-sized trees up to 45 feet tall, to multi-stemmed shrubs 9 or 10 feet tall. In very tough conditions, on frozen rocky outcroppings, it appears as a prostrate, low-growing shrub. All of these forms can exist together in parts of the US.

Common Juniper is easy to distinguish from other junipers because its leaves are all the spiky awl-shaped type without any scaled needles.

As with other junipers, Common Juniper has given rise to many ornamental cultivars, both in shrub and tree form. One of the most popular tree forms is ‘Compressa,’ also known as “Pencil Point Juniper” for its extremely narrow columnar shape. In the opposite direction is Juniperus communis var. depressa, a shrub form that grows 3 to 6 feet tall and up to 10 feet wide, also noted for its large berries attractive to wildlife.

Given the world-wide presence of Common Juniper, it is not surprising that humans have found many uses for it over the centuries. Arguably the most successful and popular use of the berries is to flavor to gin. The words “gin” and “juniper” are both derived from the Dutch word “genever” or the French word “genievre” referring to the plant. The berries are also used to flavor roasts, especially game meats, and other foods. Eating large quantities of the berries directly is not advised as they can have a toxic effect. But the foliage, oil, bark, and berries of Common Juniper have been used around the world in medicines, soaps and fragrances, insect repellants, and in religious ceremonies.

Today, the greatest value of all 3 of our region’s native junipers, Juniperis virginiana, J. horizontalis, and J. communis, is as landscape plants that are beautiful, perfectly adapted to our climate and soil, and beneficial to birds and other wildlife as food and shelter. Consider replacing some of those fussy non-native shrubs (that you may have wrapped in burlap) with these indispensable native plants.

THIS BLOG IS WRITTEN BY CATHY LUDDEN, CONSERVATIONIST AND NATIVE PLANT EDUCATOR; AND BOARD MEMBER, NATURE CENTER at greenburgh. FOLLOW CATHY ON INSTAGRAM FOR MORE PHOTOS AND GARDENING TIPS @CATHYLUDDEN.

Featured photo: Yellow-rumped Warbler on Juniper — Sav DiGiorgio @Savwildlifephotography

In 1584, English explorers Arthur Barlowe and Philip Amadus were sent by Sir Walter Raleigh to investigate the North American coastline. After finding shallow water and encountering a fragrance “so sweet, and so strong… as if we had been in the midst of some delicate garden,” they landed on Roanoke Island, just off the coast of today’s North Carolina. There, they encountered the fragrant trees and described them as “the tallest and reddest cedars in the world.” Though the first settlement at Roanoke was doomed, the trees so admired by these earliest explorers proved enormously valuable to early American colonists.

But Barlowe and Amadus had the identification wrong. The Eastern Red-cedar is not a cedar at all. It is America’s most important juniper, Juniperus virginiana. Junipers and cedars both have aromatic qualities, which is probably the cause of the confusion, but true cedars are in the genus Cedrus, and not native to North America. Today, the common name of the American tree is either hyphenated (Red-cedar) or condensed to one word (Redcedar) to reduce that confusion.

The wood of Red-cedar is rot-resistant and has a natural insect-repellant quality, so colonists used it for fence-posts, coffins, and furniture. Scraps of wood chips and saw dust were useful for bedding to repel fleas and combat odors. And indigenous people shared many medicinal uses of Red-cedar bark, leaves, and berries.

But today, the most important use of Eastern Red-cedar by far is as a landscape plant. Juniperis virginiana is native to 37 states in the Eastern US from Minnesota to parts of Texas and from Maine to Florida. The tree is typically 30 to 40 feet tall, but old cultivated specimens can reach 90 feet. It is long-lived, with some trees known to be over 500 years old. It is attractive, with dark green foliage that may turn gray or bronze in the winter. And it is unbelievably tough!

Eastern Red-cedars can survive extreme temperatures from -45 degrees Fahrenheit to +105 degrees. They are also drought tolerant, salt-resistant, and tolerant of windy conditions, so they do well along roadsides, driveways, and walkways. They are not at all fussy about soil and can succeed in poor dry soil, acidic or alkaline soil, and even in swampy land. They do not need pruning, but will tolerate being clipped as a hedge or even used for topiaries! Though they prefer full sun, Red-cedars can grow in part-shade.

Juniper leaves are needle-like and prickly when the tree is young and also on new growth, but older leaves are made of overlapping scales and are softer to the touch. The trees are dioecious, meaning male and female trees are separate plants. The female trees are wind-pollinated by inconspicuous flowers on male trees and produce small blue-grey cones that look like berries.

Eastern Red-cedar is critically important to wildlife – except deer! Deer tend to avoid the prickly, aromatic foliage, while birds flock to the grayish green waxy berries. Robins, mockingbirds, juncos, cardinals, and over 50 other bird species eat juniper berries. The dense foliage also offers winter shelter for many small animals and safe nesting sites for birds and squirrels in the summer.

The nursery industry is offering numerous cultivars and selections that make Eastern Red-cedar appropriate for a wide variety of landscape designs. A “weeping” form is called Juniperus virginiana ‘Pendula.’ J.virginiana ‘Taylor’ is tall and very narrow, almost pencil-shaped and makes a real architectural statement.

J. virginiana ‘Emerald Sentinel’ is said to bear lots of berries. ‘Brodie’ is an elegant cultivar that is narrower and smaller than the species at 6 to 8 feet wide and 20 to 30 feet tall.

With these options, it is not difficult to find an Eastern Red-cedar that will work in your landscape.

In recent years, Eastern Red-cedar has received some bad press for two reasons – both deserve mention here.

First, Red-cedar has been called “invasive” by those describing its aggressive spread into pastures, meadows, and prairies where it can replace grasses and wildflowers, eventually creating a mono-culture of Red-cedar trees. Though the word “invasive” is not appropriately used referring to a native plant, it is true that Red-cedar seedlings can quickly overcome open areas that are not well maintained. It is a “pioneer species” like aspen or yellow poplar, and will move into areas where ground is newly opened and untended.

While the unwanted spread of Red-cedar is a maintenance problem in several states in the Central and Great Plains regions of the US, it is not a concern that should prevent the wide-spread use of the tree in residential landscapes in the East. Any seedlings popping up in construction sites or roadsides here are a bonus, certainly preferable to the truly invasive non-native plants that dominate our region.

The second issue with Eastern Red-cedar is its role in the life-cycle of a native fungus called cedar-apple rust. The fungus appears in areas where Red-cedar and other junipers grow within a mile or two of apple or crabapple trees. Where apples are grown as a commercial crop, growers will avoid having Red-cedars or other junipers growing within a few miles of an orchard. Red-cedars are not usually harmed by the fungus, but the fruit of apple trees can be ruined. Commercial growers use fungicides as well as limiting the proximity of the two trees. Damage to crabapples is usually limited to yellow spots on the leaves. If the infestation is very severe, defoliation can occur.

Although cedar-apple rust is a consideration if you want to have both crabapples and junipers in your yard, the problem can be controlled by having a knowledgeable arborist apply fungicide at the correct time in the cycle. If you are growing apples for the table, adding an Eastern Red-cedar to your landscape is not recommended.

But if you ask the birds, they will strongly urge you to plant more Eastern Red-cedars!

THIS BLOG IS WRITTEN BY CATHY LUDDEN, CONSERVATIONIST AND NATIVE PLANT EDUCATOR; AND BOARD MEMBER, NATURE CENTER at greenburgh. FOLLOW CATHY ON INSTAGRAM FOR MORE PHOTOS AND GARDENING TIPS @CATHYLUDDEN.

After Halloween and a little before Thanksgiving, Witch-hazel (Hamemelis virginiana) starts blooming. It’s always a surprise to see its bright yellow flowers appear just as fall colors fade and branches are bare.

Witch-hazel is a fascinating plant. It’s a multi-trunked shrub or small tree that evolved as an understory plant in the forests of the Northeastern US. You might not notice it at all in the spring or summer when it sits modestly under bigger trees in part shade. But in early winter, when most plants are going to sleep, Witch-hazel is hard to miss. Its flowers are fragrant, and adorned with tiny yellow streamers reaching out in all directions.

The leaves, bark, and twigs of Witch-hazel contain tannins and flavonoids that Native Americans used for centuries to treat skin ailments. European colonists soon adopted the practice, and today Witch-hazel is one of the few plants the Food and Drug Administration has approved for use in over-the-counter products. Many cosmetics companies use Witch-hazel in toners, diaper rash remedies, acne treatments, pore reducers, and after-shaves.

A more questionable early use of Witch-hazel was the practice of using forked branches as dowsing or divining rods to search for underground water. A “water witch” would hold the forked end of a Witch-hazel branch and walk until the flexible tip supposedly dipped when underground water was detected. Dowsing with Witch-hazel branches for well-digging was a common practice right into the 20th century.

The real mystery of this plant still isn’t settled. Why does Witch-hazel start blooming in winter when most pollinators are already hibernating? And which insects do pollinate the flowers? Some researchers have pointed to a moth species that survives freezing temperatures by shivering so hard that its body is actually warmer than surrounding air temperature. Others have suggested that a small and very late-acting bee is the pollinator. Still others have theorized that swarms of tiny gnats do the job. More research is required.

But the coolest thing about this fascinating plant? Because of its strangely late pollination, there isn’t time for the seeds to ripen in the same year the flowers open. It takes the whole next summer for seeds to slowly ripen in their pod. Then, just as the flowers start blooming again in the freezing cold, the pod explodes throwing ripe seeds 10 to 20 feet away, where they will rest until spring weather is warm enough for germination. It’s a risky reproduction strategy, but it seems to work well for this native plant.

Witch-hazel is an easy choice for smaller properties. As a multi-trunked tree or shrub, it rarely exceeds 20 feet in height. It is an understory plant, so it does well in part shade under mature trees, but is also happy with more sun. It is winter-hardy in Zones 3 to 8, and is not fussy about soil, but average moisture and a covering of leaf litter throughout the season is recommended. No special care is required and Witch-hazel rarely needs pruning. In summer, it is an open, airy plant with medium green leaves, but in fall, the leaves turn apricot gold before dropping just as the crazy flowers start to open. The flower show typically lasts a month or more.

Lately, we’ve seen nurseries offering non-native hybrids of Witch-hazel for sale. These varieties with orange or red flowers are recent introductions of hybridized Asian species, so their value to our native wildlife and potential for invasiveness are unknown. Our view is that it’s always safer to go with species that evolved in our region.

Hamemelis virginiana, our native Witch-hazel, is a garden-worthy plant that brings late-season interest to suburban landscapes. Try it against a background of evergreens or with berry- producing shrubs. On a cold winter’s day, you won’t be sorry.

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.