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.

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

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?

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: 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.

Top Ten Perennial Picks for Jazzing Up Your Garden

While attending New England Grows earlier this month, a trade show that highlights new trends in landscaping and horticulture, I heard that Tony Avent was scheduled to speak. His topic was “100 Perennials I Wouldn’t Garden Without”, and I knew I couldn’t miss it. Tony Avent is a plant explorer, hybridizer, all-around plant guru, and owner of the famous Plant Delights Nursery, a mail-order and retail nursery in North Carolina. This exciting nursery is dedicated to offering the best, the newest, and the strangest garden-worthy perennials to gardeners around the world

Tony’s enthusiasm about plants is contagious. I walked away wanting to try every plant he mentioned, but was able to create a short-list of ten fabulous, unusual perennials.

Japanese Peony (Paeonia japonica). A peony that prefers shade! Most peonies are sun-lovers, but not this charming woodland peony. It makes an 18" x 18" clump of grey-green foliage that is topped in early spring with lovely 3" wide white cups with yellow stamens. After flowering, pods form that split open to reveal incredible, gorgeous metallic-blue seeds on red stalks. The Japanese peony is recommended as a deer-resistant specimen in the woodland garden and in the shady perennial border.

Bush Clematis (Clematis integrifolia ‘Rose Colored Glasses’). Clematis integrifolia, also known as solitary clematis, is a non-climbing herbaceous perennial that forms a dense, sprawling mound 12-24” tall. The cultivar ‘Rose Colored Glasses’ produces two-inch long flowers that are rose-pink, nodding, and urn-shaped, with twisted sepals. Each flower appears singly atop its own slender stem and is followed by ornamental silver-green seed heads. It has an incredibly long bloom time, from May to July, with continued lesser bloom into September. It flowers best in full sun with adequate moisture and makes a beautiful addition to cottage gardens, meadow gardens, and perennial borders.

Heucherella ‘Solar Eclipse’.  This amazing little plant forms 16" wide clumps composed of dark purple leaves, each edged in a ring of chartreuse. It strongly resembles a zonal geranium. It retains its intense color throughout the growing season. It is topped in late spring with bottle-brush spikes of white flowers. I have grown other Heucherella cultivars, and they are easy, relatively pest-free and offer dramatic foliage. I can’t wait to try this one! Heucherellas require part sun to light shade. It should be planted in regular garden loam and looks lovely in shady gardens accompanied by hosta, epimediums and other shade-loving perennials.

‘Millenium’ Allium. This allium forms a 1’x1’ clump of narrow, glossy green leaves that is topped by 2” rose-purple flowers in late summer. Very floriferous, it will bloom for over a month. I was especially interested in it when I heard that it is the product of a hybridizing program of a well-known allium breeder from Massachusetts, Mark McDonough. Plant Allium ‘Millenium’ in full sun and this deer-resistant little plant will reward you with a full season of shiny, strappy foliage and a stunning floral display.

‘Tomato Soup’ Coneflower (Echinacea ‘Tomato Soup’). Plant hybridizers have been expanding the color-range, size and form of our native perennial coneflower. This new introduction, ‘Tomato Soup’, forms a 32” tall clump that is topped in summer with flowers that are indeed the color of tomato soup. The 5” wide blossoms are attractive to hummingbirds and bees, and its seeds are favored by birds. Echinacea are sun-loving, drought-tolerant perennials that require excellent drainage, particularly in winter.

‘Low Down’ Swamp Sunflower (Helianthus angustifoius ‘Low Down’). Finally, a swamp sunflower for the small garden! Our native Helianthus normally reach heights of 8 feet, suitable for the back of the perennial border. But this new cultivar produces 18”x18”clumps for the mid-border, that are covered in September with large, yellow sunflower blossoms. Native to the US, swamp sunflower is a sun-lover that performs well in both wet and dry soils.

Hosta ‘Dixie Cups’. This hosta is a Plant Delights Nursery introduction, and was hybridized by Tony Avent himself. I love the name. It is a medium-sized blue hosta with leaves that are cupped and corrugated. It requires part sun to light shade with adequate moisture and would look lovely planted with purple-leaved heucheras, ferns and golden Hanoke grass.

Bristle-leaf Sedge (Carex eburnean). This little grass is native from the east coast to the west coast and is hardy in Zones 2-8, yet it is an uncommon sight in the home garden. It produces 8” wide clumps of soft green, narrow foliage. Amazingly, it is one of the few grasses that will grow well in the shade. It is drought-tolerant and deer-resistant, and looks great in the woodland garden as well as the rock garden.

Sedum ‘Frosted Fire’. Sedum ‘Frosted Fire’ is a gorgeous variegated hybrid of the popular Sedum ’Autumn Joy’. It produces 15”x15” clumps of fleshy green foliage edged in cream. It is topped in late summer by red flower heads that age to bronze. Sedum ‘Frosted Fire’ is drought-resistant and easy to grow in full sun, but dislikes wet soils.

‘Lightning Strike’ Toad Lily (Tricyrtis hirta ‘Lightning Strike).  This variegated Tricyrtis makes an outstanding addition to the shade garden. Its 2’ tall arching stems are clothed with golden leaves streaked with green. In early fall, light lavender spotted flowers, appear along the stems at the leaf axils. This unusual plant is very easy to grow in conditions similar to those preferred by hostas. In fact, it makes a perfect companion plant with hostas , ferns and heucheras in the shady border.

I am already looking forward to a new growing season and am eager to give my new Top Ten Picks a try!

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!

Geraniums: Delicate Beauty for the Perennial Garden

During a recent garden tour, I pointed out a clump of beautiful hardy geraniums to my friend, and got the usual confused look. Upon hearing the term ‘hardy geraniums’, most people look for Pelargoniums, whose big, bright blooms adorn millions of flower boxes and porch planters. The term ‘hardy geranium’ however, refers to a genus of delicate mounding perennial flowers ranging in color from cornflower blues to soft pinks, mauves, purples and  deep maroons. Also called “cranesbills” for the shape of their seedpods, hardy geraniums have flowers and foliage that are smaller and finer than those of pelargoniums, and reward the gardener by returning reliably and blooming profusely year after year.

I grow only six of the 400 species of hardy geraniums that have been identified. The plants are perfectly adapted to Massachusetts gardens, thriving in zones 4-8. Most form low, dense mounds with small cup-shaped flowers that float above the foliage on thin stems, attracting bees and butterflies. The translucent flower petals look particularly beautiful when backlit. While all species exhibit five-petaled, symmetrical flowers and finely divided palmate leaves, some have contrasting splotches or veining. Even when not in bloom, hardy geraniums add beauty to the garden from spring through fall with their leaf shapes color variations.

Hardy geraniums are extremely flexible plants, and whether you are looking to fill a dry, sunny spot, an area with part shade or a groundcover for the woodland garden, you will find a geranium that will suit your situation. I love to use Geranium sanguineum, also known as Bloody Cranesbill, in place of annuals at the front of a border. The plant forms a low (8”), wide mound with a profusion of magenta flowers light up the garden all summer long. In my garden it is gorgeous combined with purple heuchera, lamb’s ears, ‘Blue Star’ juniper and bearded irises.

For those that love masses of true blue, billowy flowers, there are two wonderful geranium varieties: ‘Johnson’s Blue’ and ‘Rozanne’. ‘Johnson’s Blue’ forms 18” mounds of cornflower blue flowers that grace my perennial bed for the month of June. ‘Rozanne’, awarded the title of  “2008 Perennial Plant of the Year”, is  taller with 2.5 inch violet-blue flowers that bloom all summer, and deep green foliage lightly marbled with chartreuse. I fell in love with it when I saw the “Rozanne River” in the Bressingham Garden at Elm Bank.

I recently acquired my first Geranium phaeum, also known as Mourning Widow or Dusky Cranesbill from the Cotton Arbo-retum in Winchester, Mass. Geranium phaeum is one of the taller species, up to 32” in bloom, with purplish brown spots on its leaves and deep maroon, almost purplish black flowers. This geranium can be grown in dry shade and combines superbly with chartreuse hostas and hanoke grass.

Although it is difficult to chose a favorite geranium species, my favorite is Geranium macrorhizum (Bigroot geranium) with its bright pink flowers in early spring, scented foliage which turns a bright scarlett in autumn, and its tolerance of dry, shady areas. I am partial to any plant that survives under my massive maple trees and adds so much beauty to such an inhospitable site.

Hardy geraniums require little care once established. They prefer moderately rich soil, and have no significant pests or diseases. I shear my plants back to their basal foliage once in mid-summer to encourage new leaf growth and reblooming. (The only exception to this is Geranium macrorhizum, which can be deadheaded and needs no shearing.) Geraniums live longer if divided every 3-5 years, and your friends will be happy to receive divisions of these wonderful plants for their own gardens.

Snowdrops Carpet the Early Spring Garden

Few flowers are more appreciated than the first blossoms of spring. One of the earliest flowers is the diminutive snowdrop, usually blooming several weeks before crocuses appear. Often emerging out of a blanket of snow, the aptly named snowdrop flower resembles three drops of milk hanging from a stem. Its Latin name, Galanthus, means “milk-white flowers.” The plants grow to a height of 4-8”, and exhibit beautiful bright white blossoms punctuated with a bright green spots, and a faint honey fragrance.

Although there are more than 70 varieties of snowdrops in cultivation, only two types are widely grown – the common snowdrop, Galanthus nivalis, and the Giant Snowdrop, Galanthus elwesii. The plants are native to Europe and the Mid-East, from the Pyrenees north to Poland and east to Russia, Turkey and Syria. They have become wildly popular in the British Isles, where there are entire gardens dedicated to snowdrop cultivation. Scotland hosted its first Snowdrop Festival in 2007 with 60 gardens participating. The most famous snowdrop garden is Colsbourne Park in the English Cotswolds, the ancestral home of plant hunter Henry John Elwes, who collected the elwessi hybrids in Turkey and introduced them into modern cultivation in the 1870s.

Galantophiles are fascinated by the subtle variations between cultivars, from the double flowers of G. ‘Flore Pleno’, to the gold dashes of ‘Lutescens”, to the broad, shiny leaves of G. ikariae, or the rare autumn blooms of G. reginae-olgae.

Snowdrops grow best in areas with a cool winter, and are hardy in zones 3-7. They take full sun to part shade, and can be grown under deciduous trees or shrubs because they will bloom before the trees leaf out in the spring. They prefer moist, humus-rich soil with good drainage, but can also tolerate an area with dry shade once established. After the plants finish flowering, their foliage should be allowed to fully die down on its own. Like other members of the Amaryllis family, snowdrops are avoided by deer and voles.

Snowdrops grow from tiny bulbs, which should be planted in the garden in fall with crocuses, daffodils, and other spring-blooming bulbs. Purchased bulbs must not be allowed to dry out, so it is best to plant them immediately or soak them overnight prior to planting. Like other small bulbs, snowdrops look best planted in clumps, so plant them 2-3” apart and 3” deep. Many gardeners recommend planting snowdrops from divided fresh clumps in the spring, after their blooms have faded, but before the foliage turns yellow. If you have any friends that grow snowdrops in their garden, this is the time to ask if they will share their plants with you.

Small size and early bloom makes snowdrops ideal flowers for rock gardens, troughs, raised beds and the edges of garden beds. You will want to plant snowdrops where you will pass them frequently or see them from your window as their charming blossoms signal the beginning of spring. They naturalize freely both by self-seeding and through bulb offsets, and can form beautiful carpets in the lawn, in the shade garden or in the shrub border.

My small collection of snowdrops began when my 8-year old son brought home a blooming clump from his friend’s house. The snowdrops were admired and left in the pot through the summer. At some point the pot was knocked over, and the snowdrops rooted themselves in the mulch under the cedar tree. The following spring they appeared there and next to our pond. Last spring I decided to move them to my circular shade bed in the driveway, because I had read that miniature bulbs can be planted around the bases of hostas. They will bloom before the hosta shoots poke out of the ground, and the emerging hosta leaves will hide the snowdrops’ yellowing foliage in May. As with any small bulbs, however, you never manage to remove the whole clump, so this year I have snowdrops popping up in a number of places. I can barely wait until I am 80 and the entire garden is white with snowdrop blooms in early March.

To start your own collection of Galanthus varieties, visit brentandbeckybulbs.com and vanengelen.com.

Redtwig Dogwood Offers Vibrant Winter Color

When I first began gardening, the only dogwood I knew of was our native dogwood tree, with it's spring-time show of delicate pink or white blossoms. Yet the dogwood genus contains a huge variety of plants, ranging from woodland ground covers, to shrubs, to trees that grow to forty feet. While many of these make excellent additions to the home landscape, none are more versatile than the redtwig dogwoods. These multistemmed shrubs are garden performers all year long and provide real drama in the winter landscape with their colorful branches.

There are two species of redtwig dogwoods, the Tatarian dogwood (Cornus alba) and the Redosier dogwood (Cornus sericea). Their care, cultural requirements and effect in the landscape are nearly identical. They are easily grown and transplanted, adapt well to dry or extremely moist soils, and prefer full sun to part shade. In spring, they have flat, cream-colored flower clusters that are followed by ivory or blue berries which provide food for birds. They have a rounded shape and spread by suckers or underground stolons, especially in moist soil, forming colonies with colorful stems in winter that have great ornamental appeal.

The Redosier dogwood is native to North America and is very useful in the New England designed woodland garden, where it spreads naturally in colorful swaths. It is often planted in groups in the shrub border or massed on slopes for erosion control. The Tatarian dogwood is native to northeastern Asia. In the home landscape, it is typically planted in groups, often with needled evergreens as a background for its colorful winter stems. Both dogwood types grow vigorously in Zones 3-7, but neither does well in the heat and humidity of the south. Noteworthy varieties are C. sericea 'Baileyi', which grows 6-9 feet high with foliage that turns reddish-purple in fall and has a winter stem color of dark red; and C. alba 'Bud's Yellow',which grows to 6 feet high, has reddish fall foliage and a winter stem color that is an unusual bright yellow.

All redtwig dogwoods offer multi-season interest, but there are some that add more drama to the home garden than others. I love the cultivars with variegated leaves: their bright foliage commands attention, spring through fall. In my garden, I grow two variegated C. alba cultivars. I use 'Elegantissima', which has greenish-grey leaves edged in white, to brighten up a shady spot in my shrub border. In early spring, its red stems are complemented by a nearby grouping of yellow-flowering trout lilies (Erythronium), whose green leaves are mottled with the same dark reds of the dogwood. In summer, 'Elegantissima' mingles effortlessly with ferns and other perennials, such as hosta (H. 'Winfield Blue', H. 'Shade Fanfare' and  H. 'Dream Weaver'), a small blue grass (Festuca glauca 'Boulder Blue'), coral bells (Heuchera 'Coral Dream') and epimedium.

I have grown the variegated C. alba 'Ivory Halo' in a large planter on my deck since 2008. This may be the year it gets planted out in the garden, but I am sold on its performance, beauty and adaptability as a year-round container plant. I will definitely plant another to grace my deck. Or maybe this time I'll try a new cultivar, like 'Silver & Gold', which has green and silver foliage and cheery yellow stems in winter.

Redtwig dogwoods require pruning to retain the winter effect of vivid branch color: the brightest color occurs on the newest branches. Prune out old, colorless branches that are more than 2-3 years old; cut them back close to the ground to stimulate bright new growth.

The redtwig dogwoods offer year-round beauty in the suburban landscape. They are especially valued for their vibrant winter stem colors that are stunning when framed by the snow.  Redtwig dogwoods can be purchased at many local nurseries and from online sources such as forestfarm (www.forestfarm.com).

By Joan Butler

Winterberry Holly Is A Beacon in the Garden

or brightening the winter landscape, nothing can compare with winterberry holly. Its bright red berries are a visual stoplight in garden settings and in our New England woodlands and marshes. Winterberry is a tough native shrub that adapts to a wide range of growing conditions. In the wild, it can be found thriving in wet, boggy locations but also does well in drier sites in the woodland and home garden. Typically, it reaches heights of 6-8 feet and spreads slowly by “suckering” to form small thickets. It grows in full sun to part shade, with berry production best in full sun. The profusion of shiny berries that cover its branches from fall through winter make it a stand-out anywhere it is planted. 

Winterberry holly is part of a diverse genus (Ilex) that includes evergreen and deciduous hollies. Most people are familiar with the evergreen varieties, with their spiny leaves and red berries that are staples of holiday decor and floral arrangements. The deciduous varieties are less well-known, although probably everyone has noticed them and wondered about their identity. Winterberry holly (Ilex verticillata) is the most common of the deciduous hollies. It is native from Newfoundland west to Michigan and south to Maryland and West Virginia. The summer foliage is a rich dark green. Autumn foliage is yellow and is not considered particularly showy. The berries that color up after the first frost  are the real show-stoppers here. And, as an added bonus, the berries are a nutritious food source for birds.

There is no shortage of winterberry cultivars. “Red Sprite” and “Winter Red” are particularly favored for their prolific production of large red fruits. Also popular is “Sparkleberry”, an Ilex verticillata hybrid with a heavy fruit set and smaller berries. If you want to try something different, “Winter Gold” produces berries that are a spectacular peach-salmon color. There is even a cultivar with variegated foliage, the uncommon “Sunsplash”, with leaves that are streaked with yellow.

As is typical of most hollies, male and female flowers are found on different plants and only the female plants produce berries. If you want berries, you must have both sexes present within a distance of 50 feet of each other; one male will fertilize 6-7 females. The male must bloom at the same time as the female. Common male pollinators are “Jim Dandy”, which will fertilize “Red Sprite” and other early-flowering types, and “Southern Gentleman” which will fertilize “Winter Red”, “Winter Gold”, “Sparkleberry” and other later-flowering types.

In my garden, I grow the cultivar “Cacapon”, which I have planted in two different locations. In the mixed shrub border out back, “Cacapon” has become a six-foot tall thicket covered with red berries that I value for their winter show and contrast against the evergreens. In the front foundation plantings, it is growing as a small tree, nearly eight feet tall now, with wonderful dark grey branches and red-orange berries. Light pruning in the spring improves berry production in both locations.

If you are looking for something to brighten your winter gardens, look no further than winterberry holly. Best planted in spring and fall, winterberry can be purchased locally at many nurseries, including Weston Nurseries, and through mail order resources such as RareFind Nursery. (www.rarefindnursery.com).

By Joan Butler