Centaurea Montana: A Cottage Garden Favorite

Centaurea montana captured my interest many years ago, when I saw it in the garden of the Holliston Historical Society. The flowers of this Mountain Bluet were similar to the annual cornflower that I had grown from seed, but they were much larger, on a plant sporting silvery, fuzzy leaves and a bushy habit. Best of all, Centaurea montana was a perennial, so it would not need to be planted every year. I was sold, and shortly acquired three plants of my own.

Centaurea montana, also called “Perennial Bachelor’s Button”, has been flowering in gardens for centuries. Equally at home in cottage gardens or more naturalized settings, Centaurea is an old-fashioned flower with a relaxed habit, and long-lasting, boisterous blooms that are equally charming in a vase as they are in a garden bed. Its bright blue flowers open from attractive buds in late spring, then leave behind a mass of vigorous, silvery-green woolly foliage. In my early summer garden, the cornflower hue complements the blues of baptisia, geranium ‘Johnson’s Blue’, salvias and alliums, and contrasts with the bright yellow blooms of ‘Stella d’Oro’ daylilies, sundrops, and the foliage of dicentra ‘Gold Heart’ and lamium ‘Cannon’s Gold’.

Centaurea’s history extends all the way back to ancient Greek mythology. When Chiron the Centaur was wounded by one of Hercules’ poisoned arrows, he was cured by this herb’s amazing healing powers. In times past, Centaurea was appreciated for its astringent herb qualities, and its flowers were used to treat minor wounds, mouth ulcers and eye ailments such as conjunctivitis. Today, extracts of the plant are used in shampoos and conditioners.

As a garden plant, I have found Centaurea montana to be a versatile perennial that grows best in full sun to light shade in ordinary garden soil. It tolerates drought once established, but will not thrive in waterlogged conditions. Its short stature makes it ideal for the front or middle of a perennial border. Centaurea blooms in late May to late June, at which point I cut it back to secondary stems for continued blooms. Once the plant starts to look ragged in mid-summer, I trim back the stalks to the basal leaves, and wait for a second flush of blooms in late summer. After flowering, Centaurea montana self-seeds freely, creating welcome drifts in cottage gardens. I always have enough plants to share with friends but not so many that I find it invasive.

New hybrids of Centaurea montana have recently been introduced. ‘Amethyst in Snow’ has silky white blooms with royal purple centers. My friend Kathy grows this Centaurea in a garden filled with dark purple bearded iris, purple heuchera, and Rhododendron ‘Calsap’, with its striking white blossoms adorned by a dark purple splotch. Echoes of purple and white accented by chartreuse and yellow create a garden that is energetic and fresh.

Another new cultivar of Centaurea Montana is ‘Gold Bullion’, a dramatic combination of electric yellow foliage, black-etched buds, and lacy, bright blue flowers.

‘Black Sprite’ is a dramatic hybrid with purplish black flowers that bloom from July to August and would look terrific underplanted with Black Mondo Grass. Whether you prefer the cottage look of the original cornflower blue Centaurea, or the modern appeal of ‘Black Sprite’, Centaurea montana will add an interesting twist to your summer garden.

The Mayapple: A Native Woodland Colonizer

During my first visit to Monticello last month, I came across a wonderful book that piqued my interest in native plants. Andrea Wulf’s highly engaging The Brother Gardeners brings to life the science and adventure of eighteenth-century plant collecting, beginning with colonial farmer John Bartram who started shipping seeds of our native plants to English collectors in 1733. English plant lovers were entranced by the hundreds of unusual American trees and shrubs, from magnolias and firs, to rhododendrons and mountain laurels, to the wildflowers of the woodlands and prairies. Since Bartram lived in Pennsylvania, one of the perennials that he must have sent to England was our native Mayapple, Podophyllum peltatum, which is currently blooming in my garden.

Mayapple is yet another spring ephemeral – a perennial woodland wildflower that blooms early in the spring (May in Massachusetts), sets seed and then disappears by midsummer. Native in eastern North America south to Texas, Mayapple is hardy from zones 3 to 8, and makes a lovely addition to the woodland garden. The plants poke out of the ground looking like shiny little folded umbrellas, and then quickly unfold. From a single stem, each plant grows 12-18” tall, and produces one or two umbrella-like leaves that may be up to 12” in diameter. The leaves are deeply-divided, and a mass of Mayapples looks like a grove of miniature palm trees.

Mayapples are unique in that they have a solitary flower, which forms in the axil of the leaves. The nodding, white flower sports 6 to 9 waxy petals, and resembles an apple-blossom. (A rare new pink-flowered form, ‘Missoury May’, has recently been introduced and is available through specialty nurseries.)

The 2” blossom is usually hidden by the large leaves, so you have to get down low to appreciate its delicate beauty. After the flower is pollinated by bumblebees, each plant produces a fleshy, greenish lemon-shaped fruit (the apple) which turns golden when ripe. The fruit can be used for preserves and jellies, and apparently tastes like an overripe melon. However, since the rest of the plant—the leaves, roots, and unripe fruit—is highly toxic, I have not sampled it myself.

Mayapples are best grown in partial to full shade, in rich, well-drained, humusy soil. They will tolerate dry soil and drought once established. The plants colonize by underground stolons, forming dense mats. They do not like heavy competition from other plants. Although it is recommended that they be grown under deciduous trees, mine are growing well under the canopy of 75-foot tall Norway spruces. They are toughing it out in the company of mammoth hostas, bloodroot and Christmas ferns.

Mayapples may be propagated by root division while dormant in the fall. Each new division should have at least one bud. The plants will also self-sow in optimal growing conditions, but seedlings take several years to mature. Like trilliums, Mayapples should be enjoyed them in the garden, not in a vase. Picking the flowers is impossible without cutting the leaves as well, and the plants need the leaves to supply fuel for next year’s growth.

For gorgeous displays of Mayapples and other native woodland wildflowers, visit Garden in the Woods this month, the Framingham, Mass. home of the New England Wildflower Society. In addition to special programs, Garden in the Woods offers many unusual plant cultivars for sale, and is a great place to start your own native American plant collection.

Dwarf Crested Iris Brightens the Spring Garden

After a week of much-needed spring rain, the garden looks lush and expectant. Everywhere, there seems to be a new wonder to appreciate and admire. Hosta leaves unfurl, the blossoms of the crabapple trees are buzzing with bees, and the arching stems of old-fashioned bleeding heart are lined with dangling blooms. And, hugging the ground, a drift of dwarf crested iris offers delicate charm.

Dwarf crested iris (Iris cristata) is a small iris, less than 6 inches tall in bloom, with 2- to 3-inch wide flowers that hover just above its blade-shaped foliage. It spreads by creeping rhizomes, eventually forming a dense groundcover. It is one of the most common of the irises that are native to the northeastern United States. It can be found growing on stream banks and on wooded slopes or rocky bluffs in its native habitats. Despite its delicate appearance, it is a tough little plant that is extremely hardy (Zones 3-9).

Most people are familiar with the tall bearded iris. The flowers of the dwarf crested iris are beardless. They are very showy, with three narrow petals and three broad, down-curved sepals. The sepals are centrally marked with a yellow or white band, with a crested ridge and a white splotch. Flower color is typically shades of blue-lavender, deep violet or white.

Iris cristata ‘Alba’ is the white form of the dwarf crested iris. The flowers are a particularly bright white color that is outstanding in moon gardens. Its softly spiky form and clear color enhance other garden plants. I have planted it in front of a yellow-leaf bleeding heart (Dicentra ‘Gold Heart’), a green-edged yellow Hosta (‘Golden Meadows’) and a dark pink azalea (‘Renee Michelle’); just dazzling.

Other garden-worthy Iris cristata cultivars include the dark purple ‘Navy Blue Gem’ and ‘Eco Purple Pomp’, the light blue ‘Powder Blue Giant’ and the ruffled blue ‘Shenandoah Sky’.

Dwarf crested iris prefers well-drained soil with moderate fertility and moisture. It will tolerate drought once established. It performs well in sun or shade, but does best in part-shade. When planted in sun, it requires extra moisture.

Its ability to perform well in shade increases its usefulness. When planted in both sunny and shady areas of the perennial border, it helps create unity through repetition. At the shaded end of my mixed border, I have planted it amongst ferns, Epimediums and hostas (H. ‘Yin’ and H. ‘Allegan Fog’). In a sunnier location, it keeps company with assorted campanulas, Heuchera ‘Venus’ and Sedum ‘Autumn Joy’.

Dwarf crested iris is an excellent plant for the home garden. It is lovely planted along the edge of a path or perennial border. It will naturalize in woodland gardens, where it will produce great swaths of springtime color. Like all irises, it is deer resistant. It will grow and bloom in dry shade.

By Joan Butler

Woodland Phlox: A Natural Mingler

To many gardeners, the name phlox conjures up images of a fragrant perennial in the sunny mid-summer border. There is another phlox, however, Phlox divericata, that creates a cloud of shimmering blue and violet in woodland shade.

Woodland phlox is a delightful spring-blooming native that forms a creeping mound about one foot tall. As the common name suggests, it is a woodland wildflower, growing in forests, fields, and alongside streams. It prefers light to full shade, moist soil and a summer mulch of shredded leaves or bark. The foliage forms a mat of loosely entwined stems with semi-evergreen oblong leaves. The stems are both hairy and sticky.

Although its foliage does not have a strong presence, Woodland phlox makes up for this with ethereal drifts of flowers, in hues ranging from sky blue to violet, to rose and soft white. The sweetly scented blooms are formed in loose clusters of tubular flowers, each up to 1.5" wide, with five flat, notched, petal-like lobes that appear at the stem tips.

Woodland phlox is a natural mingler, chatting its way across the woodland floor. It weaves in and out of neighboring flowers, complementing spring flowering bulbs and providing a carpet for taller perennials.

As the leafy shoots spread along the ground, they root at the nodes, creating nice colonies. It is a great plant for naturalizing since it also self-sows to create soft drifts that blend well with other woodlanders.

Woodland phlox is what landscape design guru Piet Oudolf would call a “filler plant”. Plants are either “structure” or “filler” plants depending on their form, shape and texture. Structure plants have outspoken personalities that dominate their neighbors, while filler plants, which lack a strong presence of their own, weave around the others and fill in gaps. Filler plants like Woodland phlox, with its creeping form and soft hue, are vital to the garden, creating a seamless flow in the overall design.

Desirable cultivars of Phlox divericata include ‘Clouds of Perfume’ with its pronounced fragrance and  powder-blue flowers; ‘May Breeze’, a soft-white phlox introduced by Piet Oudolf, and ‘Blue Moon’, the favorite dark blue selection of Bill Cullina, curator of the Coastal Maine Botanical Garden.

Variegated Kousa Dogwood: The “Eyes” Have It

Plants with variegated foliage add interest and vitality to the home landscape. They brighten shady corners and create a feeling of depth and movement in the shrub border. In addition, they make a noticeable contribution throughout the entire growing season: colored leaves are longer lasting than the longest blooming flower.

Variegated plants help bring attention to plain green plants in their midst, by virtue of contrast. Large variegated plants should be selected judiciously. One or two contribute just the right amount of drama and clarification to the shrub border, too many overwhelm.

Variegation can take many forms. On some plants, green leaves are splashed or streaked with color, such as yellow, white and pink. On other plants, leaves may be edged with contrasting color. This can mean a green leaf outlined in white, or a white-centered leaf outlined in green. There are many variations on this theme, with purple, yellow and pink combining dramatically with shades of green to produce plants of stunning beauty.

One such plant is a variegated form of the popular kousa dogwood, Cornus kousa ‘Wolf Eyes’. This tough, shrubby tree reaches a height of 10-15 feet at maturity and is nearly as wide as it is tall. It is an excellent small specimen tree and is a valuable addition to the shrub border. It flowers in late spring, after our native dogwood. Each bloom is made up of four white, pointy bracts that can last up to 6 weeks. These are followed by red, raspberry-like fruits that are produced in late summer.

Like other kousa dogwoods, ‘Wolf Eyes’ prefers fertile, acidic soil that is neither very wet nor very dry. It is considered disease-free and has few pests. Mature trees have mottled, attractive bark that adds to its beauty and provides winter interest.

It is the show-stopping foliage of the ‘Wolf Eyes’ kousa that sets it apart. Each 3-inch-long, grey-green leaf is margined with white. This contrasting leaf edging emphasizes the leaf shape: elliptical with wavy, rippled edges. New summer growth is flushed with pink, as are the new branches. Fall brings these pink tones to every leaf, for a distinctive autumn show.

I have planted a ‘Wolf Eyes’ kousa in my shrub border, where it simultaneously  is accented by and calls attention to adjacent all-green shrubs such as longstalk hollies and rhododendrons. It is a harmonious companion to hostas that echo its white-edged leaf variegation, such as H.’Cherub’ and H.‘Tambourine’. It is complemented by other green-and-white variegated perennials that have distinctly different forms: a dwarf striped grass and a stand of Solomon’s Seal.

Grouping different variegated plants can sometimes produce garden chaos, but this collection has a sense of serenity and harmony. This is achieved by casting the ‘Wolf Eyes’ kousa in the leading role and pairing it with plants that either have related variegation or no variegation.

Even within a named cultivar, such as ‘Wolf Eyes’, variegation can vary from plant to plant. When I was selecting my tree, I had six specimens to choose from at the nursery. The variegation was slightly different on each one, so leaf pattern was an important consideration for me, as was tree health and branch structure. Ultimately, I chose one that had extremely wavy leaves and green flecks in the white margin. This tree never fails to elicit comments and questions from guests, who find it just as fascinating and gorgeous as I do.

‘Wolf Eyes’ kousa dogwood is as eye-catching as its name suggests. Its stunning variegated foliage, white flowers and mottled bark add drama, beauty and distinction to the home garden and landscape.

By Joan Butler

Erythronium: What’s in a Name?

Every spring, there are a few new plants on my “plant lust” list – plants that I have read about or seen and just have to add to my garden. This year, the spring flowering Erythronium is high on the list. Depending on what part of the country you’re from, you may know Erythronium by a different name – perhaps Adder's Tongue, Dogtooth Violet, Trout Lily, Glacier Lily, Serpent's Tongue, Deer Tongue, or Yellow Snowdrop.

Whatever you call them, the 25 species of Erythronium are among the earliest of our native lilies to bloom in the spring. Most of the species are native to Western North America but there are also a few native to the Northeast and to Eurasia. These long-lived plants can be found in deciduous woodlands, sometimes in sizable colonies that can be up to 300 years old. They grow with other spring ephemerals such as Trillium, Hepatica and Uvullaria.

Erythronium’s distinctive silver or brown-mottled leaves basal leaves resemble the coloring of brook trout, hence the common name “Trout Lily”. Plants typically grow 6-12” tall. Their single, nodding bell-shaped flowers somewhat resemble violets. The flowers may be white, yellow or pink, depending on the species. Petals and sepals are bent backwards exposing six brown stamens. Erythronium’s flowers may last ten days to three weeks, depending on the temperature. The leaves last into June as the bulb goes dormant. They should not be removed until completely dried up, as they provide nourishment for the underground corm.

 Some of the more common species include Erythronium americanum (Trout lily,) with yellow flowers tinged with red, Erythronium albidum (White Dogtooth Violet), and the widely-available native hybrid 'Pagoda' which sports 3-5 flowers per stem in a rich yellow with a contrasting central reddish eye ring. In the garden, Erythroniums will readily hybridize if you plant two or more species together, yielding new combinations of flower color and foliage pattern.

Although Erythronium may be grown from seed, they will not flower for 4-5 years. Quicker and better results are obtained from planting corms, which are sold by many bulb suppliers and nurseries. The tiny white corms have a tooth-like shape, which lead to the common name “Dogtooth Violet”.

Like other spring-flowering bulbs, Erythronium corms should be planted in fall, 2-3” deep and 4-5” apart, and mulched well. The corms will produce stolons, and new plants will slowly spread to form large colonies if left undisturbed in optimum growing conditions. Offsets from mature plants may also be harvested and planted to increase your supply of these lovely plants.

Erythronium grow best under deciduous trees in a deep, fertile loamy soil. They should not be planted where the soil remains wet, as the corms may rot. They can also be naturalized in thin lawns or grown in shrub beds around rhododendrons and other part-shade lovers.

Erythronium are beautiful additions to the early spring garden, and combine well with species tulips, epimedium and other early bulbs. Since their foliage disappears for the summer, they can be planted where later growing perennials will take their place. I am looking forward to adding these woodland lilies to my shady border and enjoying their elegant blooms next spring.

Miniature Hostas: It's a Small World

Miniature and dwarf hosta are gaining in popularity. They are widely used in troughs and rock gardens. When planted in the landscape, they look best grouped together, accented with other tiny perennials and conifers.

An elevated position is particularly useful when planting miniature hostas, to bring them closer to eye level. This incredible planter is actually a water trough in a garden in PA. The mix of texture and form and fascinating plant choices give this distinction.

This astounding display is from a garden in Bridgewater: three rusted oil tanks cut in half, filled with miniature and small hosta. Use your imagination! Anything can be adapted for use as a container.

This trio is an example of a variegation connection, pairing plants that have different amounts of the same two colors. In the front we have 'Bitsy Gold', and the ginger is Asarum naniflorum 'Eco Décor'. Labeling miniatures discretely can be difficult. This gardener used flat river rocks with black labels, a creative solution.

'Blue Mouse Ear is a miniature/small hosta. Here it is paired with the variegated dwarf grass, 'Beatlemania', pulmonaria, and the miniature Epimedium 'Liliputian'. Many sports of 'Blue Mouse Ears' have been introduced, including 'Cat and Mouse', 'Country Mouse', Mighty Mouse' and 'Snow Mouse'.

With so many possible uses and occupying such a small amount of real estate, is it any wonder that miniature hostas are gaining in popularity?

Beautiful Bold Bergenia

Plants with “multiple seasons of interest” are all the rage in gardening circles, and for me, Bergenias fit the bill. Most Bergenias are evergreen perennials that remain attractive all year. Their rounded, bold leaves set off the feathery foliage of ferns and conifers, the slender leaves of iris, or the small oval leaves of boxwood.

As cooler weather sets in, the leaves develop rich winter coloring, ranging from purple to maroon, crimson, bronze and even beet red. Popular in Europe, these valuable plants have been largely neglected by American gardeners. If you want to add a lush, elegant, easy-care plant to your garden this spring, look for a Bergenia.

Bergenias are native to central Asia, from Afghanistan to China and the Himalayas, and belong to the Saxifrage family – closely related to Heucheras, Astilbes, Tiarellas, Rodgersias and Mukdenias. Most members of the Saxifrage family have a flower cluster held well above their basal whorl of leaves, and many grow in rocky places, hence the scientific name which means “stone breaker”. Bergenias were named in honor of the 18th century botanist Karl August von Bergen. Like other garden plants, Bergenias have inherited colorful common names that illustrate their traits: “elephant ears” for the shape of their leaves, and “pigsqueaks” for the sound that you get when you rub their leaves with your fingers.

There are ten different species of Bergenia with variations in plant height and flower colors. I grow the most popular species – Bergenia cordifolia, with its heart-shaped leaves. The plants are about 18” tall, with evergreen foliage that turns a rich burgundy color in fall and winter. In late April, red stalks produce beautiful clusters of bell-shaped pink flowers and the leaves turn to a rich glossy green. In my garden, Bergenia’s large, leathery leaves complement the finely cut maroon foliage of a ‘Crimson Queen’ Japanese maple, a small-leaved boxwood, purple coral bells and pink peonies.

I originally planted three Bergenias, which have slowly multiplied to a drift of about twenty-five. The plants grow from long, tube-like underground roots called rhizomes, and can be divided every 2-3 years to avoid crowding and ensure the best blooms. Mine enjoy a partly shaded, sloped bed, which provides excellent drainage. Other than trimming any tattered leaves in the early spring, and deadheading spent flower stalks, the plants are totally carefree. In general, Bergenias are very cold-hardy, thriving in zones 3-7 in the Eastern U.S. They prefer a somewhat protected location, however, since winter winds will scorch and tear their large evergreen leaves. I have two clumps growing on either side of a low evergreen shrub, and the windward clump always looks more haggard in the spring than the leeward clump.

Although Bergenias are outstanding foliage plants, you can find variations in bloom color from white to ruby red and purple. Interesting varieties include ‘Bressingham White’ (white blooms), ‘Baby Doll’ (baby-pink), ‘Apple Blossom (pale pink with red calyx) and ‘Eroica’ (reddish pink).

For something completely different, you can grow one of the recently introduced variegated cultivars. ‘Tubby Andrews’ is green streaked with gold and cream, while ‘Solar Flare’, is similar to a hosta, with a green center and irregular cream and yellow margins. Both sport dark pink blooms. When the cold weather hits, the foliage of these plants takes on various tints of pinks and reds, creating a real showstopper in the garden.

No matter which Bergenia you choose, you will be rewarded with many seasons of beauty in your garden.

Welcome Spring with Species Tulips

We are all familiar with the grand Dutch hybrid tulips that grace our gardens in late May, and were the cause of  the “Tulipmania” frenzy in Holland 400 years ago. But the parent cultivars of those tulips, less well-known but equally beautiful, are the “species” or “botanical” tulips. Smaller and simpler than hybrid tulips, species tulips delight the gardener with vivid colors, diverse forms, interesting foliage and arresting fragrance from early April to early May.

I had always thought that tulips came from Holland, and it wasn’t until a trip to Istanbul ten years ago that I learned that they are actually indigenous to Central Asia. Tulips have been cultivated in Turkey for almost one thousand years, and were brought to Europe by an Austrian ambassador to the Turkish Empire. European gardeners saw a resemblance between the flower's shape and Turkish headwear, and dubbed the flower "tulipan", from "tuilbend", the Turkish word for "turban". Tulips were favored by Ottoman sultans, who staged poetry and musical evenings in their expansive tulip gardens, illuminated by candle lanterns on tortoise backs. The reign of Sultan Ahmed III (1718-1730) is in fact called the “Tulip Era,” an era of peace and tranquility, when tulips enjoyed particular popularity in the arts and folklore. Tulips are still widely used to embellish tiles, ceramics and textiles today, and I happily brought home a souvenir tile set decorated with a tulip motif.

Species tulips still grow wild in the mountain ranges, gorges and remote meadows of Central Asia, but they also thrive in the US zones 4-7, preferring areas where winters are neither too warm or too wet. They prefer full sun and excellent drainage. Unlike hybrid tulips, they are hardy and long-lived. Because they thrive in poor soil and rocky areas, species tulips are a classic choice for rock gardens. They look wonderful planted in casual drifts in the woodland garden or combined with other spring bloomers such as grape hyacinths, windflowers and small early daffodils at the front of the perennial border. Species tulips should be planted in groupings of at least 6 bulbs for best effect, and each bulb should be surrounded by sharp sand during planting. This provides the drainage that they demand and protects the bulbs from tunneling rodents.

With more than 150 cultivars offering a wide range of colors, sizes and interesting foliage, it is easy to develop your own “Tulipmania” for species tulips.  Some of the most popular include Tulipa kaufmanniana, the Waterlily Tulip, whose flowers open wide to form six-pointed stars, and T. fosteriana, a bright red species that is widely available. Other notable varieties include T. tarda, with white star-shaped blooms and bright yellow centers, T. clusiana, the Peppermint Tulip, with creamy white and red striped petals and T. pulchella, a small early bloomer. For exotic looks, you can’t beat T. acuminata, the Fireflame Tulip, with its wispy, spidery, yellow and red petals. For fragrance, you can try T. sylvestris, T. marjolettii and the early blooming T. batalini, with its pointed buds that resemble a wizard’s cap.

The greatest selection of species tulips can be found in the fall from mail-order bulb nurseries, including johnscheepers.com, vanengelen.com and brentandbeckysbulbs.com.

Spring Ephemerals: Adapted for Success

There are hundreds of species of flowers that are native to the woodlands of northeastern North America, and nearly 90% of them bloom in the spring. Spring ephemerals are among the first of the woodland plants to emerge, allowing them to take full advantage of the available sunlight, moisture and nutrients of the forest floor. This gives them a head start in the race to fulfill the biological imperative of all flowering plants: the production of seeds for the continuation of the species.

However, blooming so early is not without risk. It requires unique evolutionary strategies and adaptations. Many spring ephemerals have developed complex relationships with other organisms in their eco-niche that encourage successful pollination and seed production. In addition, many have specific physical and structural characteristics that give them advantages in the potentially harsh conditions of early spring.

Small Size

Spring ephemerals are small plants. The forest floor thaws from top to bottom, so water and nutrients are available in the top level of the soil first, allowing smaller plants with their shallow root systems to become active before larger plants. This gives spring ephemerals a competitive edge in successful flower and seed production.

Growth Habit

Many spring ephemerals have physical characteristics that offer protection during the cold nights of early spring.  Bloodroot traps warm air with its thick leaves that envelop the flower bud and the flower stem, shielding them from frost. Other plants, such as Hepatica, have stems that are covered with dense hairs that resemble a fur coat. The hairs prevent ice condensation and act as insulators, thus protecting very early bloomers from damaging frosts.

Pollination

Some woodland plants bloom before most pollinators are active. For example, skunk cabbage blooms so early that the only insect pollinators available are flies. The fetid odor of skunk cabbage is an adaptation designed to attract flies and ensure pollination.

Hepatica is another early bloomer, with blossoms that span the time of available pollinators. Hepatica relies on flies as well as early bees, beetles and moths for pollination.

Our native bumble bees are essential to the reproductive success of many spring ephemerals, such as Dutchman’s breeches.

Seed Dispersal

Many woodland perennials rely on wind, or birds, or water to spread their seeds.  Others, like bloodroot and trilliums, have their seeds spread by ants, a process called myremecochory. Ants gather the seeds and store them in underground nests where they feed upon a fleshy appendage attached to each seed. In this way, the ants essentially plant the seeds in an environment where they stay protected until they germinate the following spring. A single ant colony may collect over a thousand seeds in a season, but they do not move them a great distance. In general, a seed is carried no more than two meters from the parent plant. Because offspring and parent plant remain in close proximity, their existence is easily threatened. When their habitat is disturbed or they are removed from the woodland (by changing environmental factors and human or animal activity), it is rare that they recur.

Deer Resistance

After a long winter, foraging deer are fond of fresh new plant growth.  Most spring ephemerals have developed adaptations that make them unpalatable to deer, including hairy stems and leaves, and poisonous sap.

Spring ephemerals and other early-blooming woodland perennials have developed ecological strategies for flowering, pollination and seed production that are completely reliant on the seasonal cycles of our native woodlands, on the growth patterns of our native plants, and on the availability of our native pollinators. In spring, our woodland floors are carpeted with the blooms of wildflowers that are wondrous examples of the complex inter-relatedness of the natural world.

By Joan Butler

Spring Ephemerals: Early to Bed and Early to Rise

My husband’s Uncle Charles is an avid outdoorsman who loves to hike and canoe all over the country. At the young age of 81, he is constantly conquering another river, portaging his canoe over landmass obstacles or encountering a bear in the campground of a national park. When we started writing our gardening articles last year, I learned that he is also an avid naturalist, and has been photographing our native wildflowers for years. I had just recently become interested in spring ephemerals, and knew most of them only from friends’ gardens. It was a thrill to see his photos of Hepatica, Bloodroot, Trilliums, Erythronium, Jeffersonia, Uvullaria, Jack-in-the-Pulpit, and Phlox captured in their forest habitats throughout the U.S. and Canada.

For those of us gardening in northern climates, spring ephemerals stretch the gardening season with their early blooms. Many spring ephemerals are native to our North American woodlands, where springtime begins slowly and ends with a crescendo of blossoms that carpet the forest floor in May. These early wildflowers can be effective and adaptable additions to the home shade garden.

 You will be surprised at the number and variety of cultivars of our early spring bloomers: 40 species of trillium, 20 species of erythronium, more than 100 cultivars of hepatica, to name just a few—there are ample opportunities for collectors!

As with all living things, having knowledge of a plant’s natural habitat and lifecycle produces success in the home garden. Spring ephemerals represent a unique ecological strategy and share these traits:

Quick Growth Cycle. Spring ephemerals are perennial wildflowers that develop their aerial parts - stems, leaves, and flowers - early each spring and then quickly bloom, go to seed and die back to their underground parts (roots, rhizomes, and bulbs) for the remainder of the year. Many emerge in April and are completely gone by June.

 Forest Dwellers. In early spring, the forest provides a warmer habitat than open field. Trees absorb the heat of the sun with their trunks and slowly radiate this heat to the air at night, when frost is still a threat to small plants. Until the trees leaf out, the sun’s rays can thaw and warm the soil of the forest floor. Trees also act as a windbreak, reducing the “wind chill” factor in the woodland.

 Reaching for the Light. Spring ephemerals take full advantage of early spring sun by blossoming before the forest trees leaf out.

 Moisture Lovers. Early spring is also the time of year when soil moisture is at the highest because the trees are not actively soaking up all the available water.

 Early Feeders. Soil nutrients are at their highest levels in early spring, when decay of the previous year’s leaves produces a bumper crop of nutrients in the soil. The spring ephemerals have first crack at this abundant food supply.

 Early to Bed. Once the leaves of taller plants expand and command the light and water, the ephemerals simply go dormant. Reserving the nutrients they gathered in their tubers, rhizomes, or other underground storehouses, they wait quietly until they can be “early to rise” the following year.

So if you want to add beauty and interest to your early spring gardens, look for the spring ephemerals that will enchant you with their woodland wildflower magic.

Siberian Squill: A Stalwart Survivor

When we bought our 90 year-old house in the suburbs, I anxiously awaited my first spring to see which flowers would emerge from the ground. After all, many generations had owned the property. Surely there would be a few long-lived peonies, some daffodils, bleeding hearts, and other “heirloom plants.” The property was graced with beautiful mature trees and a few overgrown shrubs, but there were no discernible flowerbeds. Grass grew right up to the stone foundation. To my surprise, there were only two perennials that had survived the years of garden neglect and emerged that first year – plain green hostas and Siberian squill.

Siberian squill (Scilla siberica) is a true harbinger of spring, emerging in the garden even before the crocuses. It is one of more than 100 species in the genus Scilla that are native to Europe, Asia and Africa. Despite its name, Siberian squill is not native to Siberia, but is found in other parts of Russia, and has been cultivated since the 1790s.

I love to look for the dark purple shoots of squill poking out of the ground – to me it’s a sure sign that the garden’s cycle of bloom has begun. Each tiny bulb produces dark green, grass-like foliage and 3 to 5 flower stalks that sport the bluest of blue flowers. The plants themselves are only about 6” tall. Each bell-shaped, nodding flower, has 6 blue petals and blue anthers. Its lovely floral scent attracts pollinating insects. The fertilized flowers form round green seed capsules and eventually release a multitude of tiny brown seeds. In no time at all, you have a carpet of beautiful blue flowers. Like other spring bulbs, squill’s foliage dies back in early summer and I simply cover it with mulch. The plants remain dormant until the following year.

Siberian squill requires no care after planting. It grows best in partial to full sun, in soils with good drainage and plenty of organic matter. Bulbs should be planted in the fall, 2-3” deep and 2-4” apart, and they look wonderful massed in drifts of 20 or more. Mine have slowly spread by seed and bulb offsets and now appear in several flowerbeds. They are perfect bulbs for naturalizing in the lawn or under deciduous trees and shrubs. By the time that the trees and shrubs leaf out in the spring, the squill are entering dormancy and no longer require as much light.

I also love the fact that squill is not a preferred food for voles, chipmunks, rabbits or deer. Voles and chipmunks have decimated many bulbs and perennials in my garden lately, and it’s a relief to find plants that they naturally ignore.

Siberian squill’s intense blue color looks wonderful when massed under a pink- or white-blooming ornamental tree or shrub that blooms at the same time, such as Amelanchier, Viburnum bodantense, or some of the early flowering cherries and small-leaved rhododendrons. It is also lovely when paired with other early blooming bulbs such as miniature daffodils, species tulips, giant crocus and glory-of-the-snow. No matter where it is planted, Siberian squill will delight you each spring and live on in your garden for many generations to come.

The Longstalk Holly: To Grow It Is to Love It

Plant explorers of the 19th and 20th centuries introduced hundreds of eastern Asian plant species into western cultivation. Many of these plants have become so common in the American landscape, that it is difficult to imagine our gardens without them. Forsythia, weeping cherry trees, Japanese maples, Sargent crabapple and old-fashioned bleeding heart are just of few of the Asian introductions we rely on to create beauty in our gardens. The Star Magnolia, double-file viburnum, and Korean lilac are also valued contributors to North American gardens.

Other introductions are less common, and sometimes inexplicably so. One of these is Ilex pedunculosa, the longstalk holly. Native to China and Japan, this evergreen holly is a large shrub or small tree with a sturdy constitution and graceful beauty. It has a dense, upright branching habit when young that becomes more open with maturity. Plants in the wild reach heights of 30 feet, but 15 feet is typical in garden settings. It responds well to light pruning, making it adaptable to the shrub border.

The smooth, green leaves of longstalk holly are 2-3 inches long and 1 ½ inches wide. They are non-spiny, with a satiny sheen and gently rippled edges that catch the light, adding to the shrub’s distinction. Its most unique feature is the bright red berries that hang from one- to two-inch long slender stalks (pedicles), resembling tiny cherries. These fruits are one-quarter inch in diameter and appear in early fall. They persist on the plant well into winter, until they are eaten by birds and other wildlife. As is common in hollies, both male and female plants are needed in order for the female to set fruit.

Longstalk holly was first grown in North America from seeds planted at the Arnold Arboretum in 1907, under the direction of Charles Sprague Sargent, a plant explorer and the first director of the Arboretum. It has proven to be long-lived and extremely cold tolerant, with some of the original specimens still gracing the Arboretum landscape. It is dependably hardy through Zone 5 and has been documented as surviving temperatures as low as -18 degrees with no damage. Like all hollies, it prefers a well-drained, slightly acidic soil. It thrives in partial shade and has no serious pest or disease problems.

My own longstalk hollies were planted over 15 years ago. They were slow-growing at first, then hit their stride and are now 10-foot tall beauties that add grace and diversity to my shrub border. Their long branches are very supple, and it is amusing to watch squirrels as they try to inch their way along the swaying branches to nibble on the tasty fruits. Towards the end of winter, the only berries left uneaten are at the branch tips, and I have seen birds attempting to jump/fly up to grab a berry on their way down. How glad I am that I planted my longstalk hollies across from my kitchen window, where I can appreciate their year-long beauty and enjoy watching wildlife feasting on their fruits.

Longstalk holly is surprisingly under-used in the home landscape. Its lustrous, wavy leaves add depth and motion to the garden as they catch the light of the sun. Its shiny red, dangling berries add unique beauty and provide food for birds and its graceful form adds elegance to the shrub border. In his book, Manual of Woody Landscape Plants, Michael Dirr calls it “the most handsome of the evergreen hollies that can be grown in northern gardens”. Easily grown, disease-free, and beautiful in all seasons, longstalk holly deserves a place in every home garden.

By Joan Butler

Liriope’s Stripes Add Flair and Finesse

One of the benefits of belonging to a garden club is that you are often introduced to new plants. Gardeners are generous folks and enjoy sharing their plants, especially when they are redesigning a garden bed to make room for new acquisitions. Healthy gardens produce a bounty of perennials that need division from time to time, and most gardeners cannot bear to toss their divisions into the compost pile. So, if there is an overflow of a particular plant, babies will be potted up and either donated to the annual plant sale, or brought to a meeting and shared with other members. That is how I came by one of my favorite perennials for the winter garden – variegated liriope.

Sometimes known as lilyturf or monkey grass, liriope is a grass-like flowering perennial from East Asia. It may be either solid green or variegated, and has been widely used in the South as a groundcover due to its hardiness in Zones 6-10. Now that much of Massachusetts is reclassified as Zone 6, it is sure to be used much more widely here as well.

Variegated liriope grows to about 12” tall, with leaves striped in white or gold. It blooms in late summer with lavender, purple or white spikes that are followed by clusters of bluish-black berry-like fruits. With its foliage holding well through the winter, variegated liriope is an ornamental perennial for most of the year.

There are two species of liriope, which dictate its use in the garden. The first is liriope muscari – a clumping perennial with typically lavender or purple blooms. Because it stays where it is planted, liriope muscari is the preferred choice for flower beds or as an edger. It combines beautifully with evergreen shrubs such as boxwoods, and with perennials with contrasting leaf shapes, such as large-leaved hostas and hellebores. Variegated cultivars include ‘Silvery Sunproof’, ‘John Burch’ and ‘Gold Band’.

Liriope spicata is the “running” liriope, a vigorous grower that spreads rapidly by underground rhizomes. It will quickly cover a wide area, making it an excellent groundcover, and can be used to retain soil on slopes and banks. It is tough enough to be planted in dry shade around trees and at the edges of walks or roads. Spicata’s flowers are slightly smaller than muscari’s, and range from white to lavender. ‘Silver Dragon’ is a variegated cultivar whose foliage and lavender flowers light up shady areas.

Variagated liriope is a deer-resistant, low-maintenance perennial. It can be grown in both sun and shade, but looks best in partial shade where its color is not diminished by lack of sunlight or washed out by an overabundance of it. It requires well-drained soil, and is moderately drought tolerant when established. I treat it just like my other perennials: amend the soil with compost when planting, fertilize once a year in the spring, and top off with a layer of mulch to retain moisture. Since the foliage stays evergreen throughout winter, I trim it off in early spring before new shoots emerge. As the plants grow and mature, they can be dug and divided to increase your supply. This is usually done in the spring, every three years or so, but is not necessary for the health of the plant. However, if you need to make room for a coveted new addition to your garden, variegated liriope divisions are sure to be a welcome gift to friends and neighbors.

Siberian Cypress: A Feathery Carpet for the Winter Garden

Microbiota decussata, commonly known as Siberian cypress, is a relative newcomer to the horticultural scene. It was first discovered in 1921, high above the treeline in the mountain ranges of eastern Siberia. It is native to only this small, remote region. For the next 50 years, the plant remained largely unknown to the Western world, partly due to the political secrecy of the former Soviet Union. It finally entered the horticultural trade in the 1970s, and has become available in mainstream nurseries in the past 20 years.

Microbiota decussata is the lone species in its genus, but is related to other members of the cypress family – junipers, arborvitae, and false cypress. What makes it a really special garden plant to me, though, is its low, spreading form, cold hardiness, and ability to grow in the shade. With long stems that radiate from the plant’s crown, Siberian cypress reaches a height of only 12” but a dazzling spread of 10’ if given the proper growing conditions. Its foliage is soft and feathery, bright green in spring and summer, turning to a bronzy-purple color in the fall and winter.

Siberian cypress is very cold hardy, surviving Zone 3 (-40 degrees F) winters with ease. It grows on a variety of soils, but needs good drainage. Although it tolerates drier soils once established, a mulch of wood chips, bark or pine needles is recommended to keep the root zone cool and moist. The only other maintenance that I perform is to remove dry leaves that become matted in the shrub’s crown in fall and winter. These can lead to yellowing and eventual die-back of the evergreen fronds.

When it was first introduced in the US, Siberian cypress was touted as a groundcover for shade. Since most conifers, especially the low ones, prefer full sun, this was a major selling point. Although Microbiota will grow in full sun, it prefers a lightly shaded position – not dense shade. I planted my first Siberian cypress 18 years ago in one of the most challenging spots in the garden – beneath a grove of Norway and sugar maples and hemlocks. The lack of moisture and sunlight has kept the plant at a modest 24” diameter, but it has survived. Another Microbiota, planted many years later at the foot of my rhododendrons in partial shade and better soil, extends its lush branches to form a gorgeous 8’ wide circle. With no major pests and diseases, and not bothered by deer or voles, Siberian cypress is a shrub that I can easily recommend to others.

Siberian cypress has many uses in the landscape. Although attractive alone, it is stunning in large groupings. Its low stature, wide spread and ferny, layered foliage, make it an ideal groundcover. I particularly like its texture contrast with broadleaf evergreens such as rhododendrons, hollies, pieris and mountain laurels. In the summer, it is a wonderful companion to large hostas. But the time of year that I appreciate it the most is during my winter walks, when I see how much this hardy survivor from Siberia adds to the beauty of my garden.

Hellebore Foetidus: A True Winter Charmer

When I first became interested in hellebores, Hellebore foetidus was not at the top of my acquisition list. After all, who would want to brush by a “stinking hellebore’ in their garden? Luckily, I couldn’t resist a beautiful healthy specimen at the local big box store one day, and the Stinking Hellebore has become one of my favorite perennials to grow and share.

Although fairly common and easy to find in nurseries, Hellebore foetidus is not widespread in home gardens. It is one of the most interesting hellebores to cultivate, however, especially if you live in the Northeast. Few hellebores are as showy during the late fall and winter, when most perennials are chilling underground. Hellebore foetidus stands proud and tall, looking like a miniature rhododendron. The plant is 2’ tall with spidery evergreen foliage that remains a lush dark green throughout winter. Certain varieties also have distinctive red markings on the stems and along the deeply divided leaves. The bear-claw shape of its leaves has produced a second common name – ‘Bear’s Foot’. The distinctive foliage texture makes this hellebore an interesting companion to almost any plant in the garden.

The icing on the cake are the Stinking Hellebore’s chartreuse bell-shaped buds and flowers that perch proudly atop its beautiful foliage. How many plants boast more than 6 months of bloom, starting in November? Just as the rest of the garden hunkers down for the winter, the Stinking Hellebore forms lush pale green buds that open into clusters of l” flowers with chartreuse bracts. In the early spring, these blossoms are covered with early pollinators that help to disperse the seeds.

After a couple of years in the garden, I was very excited to find baby hellebores growing in the shade of the mother plants, and transplanted a few to my nursery bed to see how they would grow. Like other caulescent hellebores, the Stinking Hellebore is fairly quick (by hellebore standards) from seed to bloom, often blooming in its second year. Mine grew into stout little plants that first season, and I transplanted them into a new area of the garden. Since that time, I have been careful not to mulch around the hellebore plants, and have impressive colonies of both  Helleborus foetidus and niger in my shade bed. Stinking Hellebore plants can be short-lived, so it’s good to let them set seed to provide a constant supply of new plants.

Helleborus foetidus prefers woodland conditions with deep, fertile, moist, humus rich, well-drained soil, and dappled shade. The species is, however, drought tolerant once established. Plants should be shielded from winter winds. Stinking Hellebore has no serious insect or disease problems and all parts of the plant are poisonous, so it is not bothered by deer or voles. And what of the smell? I have found the plants to have a mildly unpleasant odor when bruised, but the scent of the flowers does not deter me from cutting them for a vase. I just don’t keep them on my bedside table.

Hellebore foetidus has many uses in the landscape. With its intriguing, finely cut, dark green foliage, it makes an interesting and nearly evergreen groundcover for average to dry shade. It is also impressive as a single specimen when given plenty of sun. I grow mine in two partly shaded entry gardens with other hellebores, variagated liriope, leucothoe ‘rainbow’ and hostas, where its distinctive form, texture and bloom welcome visitors all through the year.

Hellebore 'Snow Bunting' is Sure to Please

Hellebore 'Snow Bunting' is one of my favorites - an early bloomer in my Zone 5 garden. Its buds begin poking out of the ground in early December, and depending on the severity of the winter, will open in February or March.

This hellebore is an unusual plant from the esteemed Yokoyama Nursery in Japan, a difficult to produce hybrid between H. niger and H. x hybridus.

Each plant produces a beautiful bouquet of pure white, outward-facing flowers that last for months, turning a soft light green as they age. A lovely sight!

Blue Hosta in the Garden

There are very few perennials available to us here in New England that offer the color and form of blue hosta. With colors ranging from deep blue to powdery light blue, they offer a quiet presence that can be used almost anywhere in the shade garden. Plants range in size from giant to small and display a variety of forms and leaf shapes.

Actually, blue hostas are green hostas with a coating of white wax on the leaf  surface, which makes them appear blue. Blue hostas prefer shade: too much sun melts the waxy coating. Like most hosta leaves, they change color throughout the growing season. Blue leaves eventually turn to shades of green.

'Dress Blues' (above) is a medium hosta that forms an upright mound of blue leaves with a yellow margin that lightens to cream as the season progresses. Hosta and ferns make lovely bed-fellows with the delicate fern fronds contrasting and complementing the solid hosta leaves. The dark stems of this fern play off the blue of the hosta leaves, creating subtle harmony.

Conquering Dry Shade

Dry Shade: the words alone are enough to strike fear in the heart of the most intrepid gardener. I recently came across a newly published book that inspires you to garden in the most difficult part of your yard. Written by Graham Rice, Planting the Dry Shade Garden: The Best Plants for the Toughest Spot in Your Garden is a wonderful resource for shrubs, groundcovers and perennials that will survive inhospitable conditions under maple trees, in dark side yards, and on the north side of buildings. 

In this book you'll learn how to prune selectively to admit more light and how to amend soil to increase its moisture retention. You'll also learn about more than 130 plants that accept reduced light and moisture levels. There is an entire palette to help you transform challenging spaces into rich, rewarding gardens. This concise and beautifully illustrated book is a great addition to your garden library.

Graham Rice is an internationally recognized expert on annuals of all kinds who has written 23 books. He trained in horticulture and botany at the Royal Botanic Gardens, Kew, and is a garden writer for London's Evening Standard.

New Hellebore Cultivar Blooms Early

New varieties of hellebores continue to be introduced. Thanks to the busy German breeder Hueger, a new cultivar of Helleborus niger has been introduced which blooms as early as Thanksgiving. It is an outstanding bloomer, with a great display of 2-3” pristine white single rose flowers by mid December. This compact new cultivar, growing to  roughly 12” x 12”,  is being marketed under the name Helleborus ‘HGC Jacob’. (HGC stands for Helleborus Gold Collection). It is hardy in zones 5-9.