As visitors stroll the display gardens at the farm, they often ask us about the plants they see in the borders and beds. No plants generate more questions than Alliums. Members of this genus are available in a broad range of colors – from various shades of purple to pink, true blue, yellow, and white, but the hallmark of this family of plants is a form that is both playful and utterly distinctive. Larger cultivars such as Alliums ‘Globemaster,’ form sizeable spheres (in this case 8-10” flower heads) that appear to float like balloons above other plants in the border. Smaller varieties including the delightful Drumstick Allium (Allium sphaerocephalon), produce lollipop-sized orbs on slender stems at a lower height.
Alliums are more commonly known as Flowering Onions, a pedestrian name unworthy of these remarkable plants.
It’s worth mentioning that Alliums, like Daffodils, are deer and rodent resistant, thanks to their faint oniony scent. The odor is not noticeable above the ground unless the leaves are cut or bruised, and many of the flowers have an enchanting, sweet scent. There are hundreds of species within this under-appreciated genus, and we annually struggle to restrain ourselves to a reasonable selection. They are reliable perennials when they get good drainage and plenty of sun.
Using Alliums in the Garden
Alliums offer colorful, distinctive, and long-lasting flower forms that are standouts in the early summer garden (there are some fall bloomers as well). They love sun and prefer a well-drained, even sandy, soil as long as it has sufficient nutrients. Tuck the bulbs around clumps of summer-flowering perennials where the Alliums’ withering foliage will be hidden by the expanding perennials. Some combinations we use at the nursery include Allium ‘Globemaster’ among Echinacea (Purple Coneflower); Allium sphaerocephalon (the Drumstick Allium) with Yarrow, Asiatic Lilies, or Phlox; and Allium cristophii (Star of Persia) with Salvia ‘May Night,’ Alchemilla mollis (Lady’s Mantle), or Roses. We offer 5 varieties of the shorter Alliums (10–30″ tall) as A Big Mix of Little Alliums. They look best along the edge of a shrub border or planted in front of late-blooming perennials.
How to Care for Your Allium Bulbs
Light/Watering: Most Alliums grow best in full sun, with at least 6-8 hours of direct sunlight a day. Those we offer require well-drained soil and are longest lived in locations where the soil is on the dry side during summer dormancy.
Planting: Plant Alliums more shallowly than comparably sized bulbs, just one to two times the diameter of the bulb deep.
Fertilizer/Soil and pH: Alliums prefer well-drained, fertile soil. Fertilize in fall and spring with any bulb fertilizer.
Continuing Care: The leaf tips of many varieties, especially the tall ones, begin to brown before bloom time. Remove the spent flowers (except from varieties that are sterile, such as ‘Globemaster’) if you wish to prevent them from self-sowing.
Pests/Diseases: Alliums have few problems except when planted too shallowly or in wet soil.
Companions: Place Alliums behind heavy-foliage plants such as Peonies and Iris. Good for bedding, and in mixed borders. Flower heads are good for drying.
Dividing/Transplanting: Alliums rarely need transplanting or dividing, but this can be done when the bulbs are dormant.
Flamboyant blooms on stately, splendid plants grace the garden in June. Bearded Irises are available in a veritable rainbow of colors, from vibrant primaries, to subtle bicolors and gentle pastels. Breeders have introduced a variety of reblooming Irises, which have a tendency to flower again from late summer into fall depending on climate and growing conditions. Please note that Bearded Irises may not bloom the first year after planting.
Light/Watering: Full sun and well-drained soil are important for vigorous growth and flowering. Do not overwater, as too much moisture in the soil can cause the rhizomes (roots) to rot, but do water deeply during summer drought. Consistent watering is especially important for reblooming Irises.
Fertilizer/Soil and pH: Iris will not tolerate soils that are wet in winter. Good drainage is important all year, and a pH near neutral (7.0) is preferred. In climates with very hot summers, plant the rhizome just below the soil surface; in cooler climates, the top of the rhizome should be exposed. Do not mulch around the rhizome as this practice may encourage rot. Fertilize in early spring with an all-purpose fertilizer scratched in around the plants, avoiding direct contact with the rhizome. Reblooming Irises perform best if fertilized again after the first wave of flowering is finished.
Pests/Diseases: The Iris borer, the worst pest of these lovely plants, overwinters as eggs in spent leaves, so don’t give the critters a hiding place. The borers emerge in the spring as tiny caterpillars, which spend a couple of weeks boring through the leaves down into the rhizome, where they grow fat and cause great damage, often leading to soft rot that causes even more damage. Vigilance can help—it’s actually possible to kill the borers in situ if you catch them early enough. You’ll see vertical streaks in the leaves; that’s your guide to help you squash the pests. If you see any signs of rot in the rhizome, dig it up and remove the affected parts. Unless the infestation is severe, plants usually recover, or grow lustily enough that you can salvage healthy chunks to keep growing. The rhizomes may also become infected with soft rot. Well-drained soils are important, so add sand if your soil is heavy and plant so that the top of the rhizome is above the soil line. If soft rot does occur, dig out and discard affected rhizomes and cut away any smaller areas of damage.
Reflowering: Remove spent blooms consistently; Bearded Irises will flower sequentially on buds spaced along the stems. After blooming is finished, cut flower stems down at their base. Although reblooming varieties have a tendency to rebloom, sending up new fans that sport flower spikes as they mature later in the season, they are not guaranteed to bloom a second time. Repeat bloom is dependent on many things, including geographic location and growing conditions.
Dividing/Transplanting: Divide your Irises when the clump becomes crowded and bloom diminishes, usually every 3 to 4 years. The timing of division is very different than that of most perennials, because Bearded Irises go dormant shortly after flowering, and summer is the ideal time to dig up the rhizomes. Even though reblooming Irises don’t go dormant, this is also the correct time to divide those varieties. Break the rhizomes into pieces or cut them with a sharp knife. Select divisions with healthy fans of leaves, most likely from the outermost part of the plant. Discard the crowded interior pieces, and any that show signs of soft rot; dispose of these in the trash, not in the compost. This is the time to trim the leaves back to about 6 inches in length. Some gardeners like to dust the cut surfaces with powdered sulfur, or to dunk rhizomes in a solution of 1 part bleach to 10 parts water. We haven’t found this step necessary, but it might be advisable if you have had problems with rot. Replant promptly. You will probably find yourself with extra divisions you can share with friends.
End-of-Season Care: After hard frost in the fall, cut foliage back hard, remove any foliage that appears spotted or yellowed and dispose of all debris in the trash. We recommend winter protection in cold climates, especially for the first winter after planting. We suggest covering the rhizomes with an inch or two of sand topped with a light layer of evergreen boughs, applied after the ground freezes and removed when the Forsythias bloom the following spring.
Calendar of Care
Early Spring: Diligently remove and destroy any old foliage to allow for fresh, new growth and prevent Iris borers from emerging as the weather warms. Remove any winter mulch. Feed plants with an all-purpose fertilizer scratched in around the plants, avoiding direct contact with the rhizome.
Mid-Spring: Watch vigilantly for the telltale signs of Iris borers in the foliage — dark vertical lines that may appear watery show up in the leaves. Squash the bugs where they live; if infestation is severe, remove affected foliage completely and destroy.
Late Spring: Taller forms may need staking. Deadhead as flowers fade, and cut entire flower spikes down at the base when blooming is finished. Fertilize reblooming varieties again after the first wave of flowering is through.
Summer: If plants need dividing, complete this task after flowering finishes and then trim the foliage back to six inches. Water divisions well during dry periods.
Fall: After hard frost in the fall, cut foliage back hard, remove any foliage that appears spotted or yellowed, and dispose of all debris in the trash. Winter protection in cold climates is recommended, especially for the first winter after planting. After the ground freezes, cover the rhizomes with an inch or two of sand topped with a light layer of evergreen boughs; remove when the Forsythias bloom the following spring.
It was a heck of a winter here in the Northeast, and we use the past tense hesitantly because we’re now in the midst of one of the cruelest and coldest Aprils any of us can remember. The calendar says April, but it feels more like February. But even if the temperatures remain significantly below normal for this time of year, and even if our gardens are still being glazed by sleet and occasional snow, spring finally seems to be making a stand. At least that’s what some of our favorite, most reliable perennials are telling us.
These quiet stars of the early spring garden won’t upstage the colorful blossoms of Crocus, Daffodils, Hyacinths and Tulips, but they’re among the first perennials to emerge and they go on to give the some of the longest performances of any herbaceous garden plants, finishing only with the arrival of hard frost. The sight of these stalwarts never fails to stir our hearts. They soldier through the most brutal winters, and as the first signs of spring begin to appear, they bring color, anticipation and even hope to a new season. A handful of these plants are past winners of the Perennial Plant of the Year award, and they’re among the most garden worthy plants we know. Below, we show each of them breaking ground in early spring, then, in a second shot, you’ll see the same plants at the peak of their development later in the season. The “spring” photos were all taken in mid-April in a Zone 6a Connecticut garden amid the snow, sleet and chill of this late spring. The plants, as you’ll see, were unfazed. Roused by the strengthening sunlight and longer days, their presence keeps insisting that spring has arrived, even if Old Man Winter hasn’t quite gotten the message.
Brunnera ‘Jack Frost’ (False Forget-Me-Not)
Prompt in its early spring arrival, the heart-shaped foliage of this shade garden favorite is a delight to behold. The green leaves, veiled and veined in silver, first appear as tiny as teardrops, and they gradually gain in size. Sprays of small blue flowers resembling Forget-Me-Nots arrive on slender stems in May and June, but it’s the foliage that counts. It continues looking beautiful straight through until autumn’s hard frost.
Alchemilla mollis (Lady’s Mantle)
A fuss-free beauty for the edge of part-shade borders, this tough but lovely plant is utterly distinctive in color and foliage. Pleated buds open into broad, kidney-shaped leaves with scalloped edges. The soft green color of the leaves blends beautifully with purples, blues, and pinks, and the the frothy chartreuse flower clusters that emerge in June and July energize and enliven any border’s edge.
Sedum ‘Autumn Joy’
This essential, drought-tolerant perennial for hot, sunny gardens is simply unstoppable. The thick, blue-green succulent foliage breaks ground at the first signs of spring then rises on stems to 18-24”. Greenish-white flower clusters cap the mounding plants in summer, and the flowers open rosy pink in August. Toward fall, they deepen to wine, and they can be left on the plant to dry and catch snowflakes in winter.
Nepeta ‘Walker’s Low’ (Catmint)
This Lavender-lookalike is one of the great garden plants. Starting early, it sends up masses of gray-green leaves, which appear in tidy mounds that are perfect for edging a border or walkway. As the weather warms, plants produce flower spikes with the lavender-blue blossoms. Adding to the pleasures this plant provides is the tangy scent of its leaves, which stirs the senses at the start of the gardening season. To help plants maintain a neat habit, shear them back by two-thirds after the first bloom. Plants will continue flowering until frost.
Geranium ‘Ingwersen’s Variety’
This Scented Geranium at first seems too pedestrian to belong on many must-have lists, but when you see the way it performs in your garden, you’ll want more. A superb ground cover for sun to part-shade, this rugged, carefree grower produces a mound of deeply dissected green leaves that look fabulous all season long. Spring brings a sprinkling of 1” pastel pink blossoms, but we love it best for the beautiful, aromatic foliage that blazes orange and red in the fall. These plants spread efficiently but are not invasive, they tolerate dry shade, and they smother weeds in the bargain.
Iris pallida ‘Variegata’
Like rays of sun emerging from the soil in spring, the yellow-variegated blades of this exceptional Iris show themselves early. The warm golden color is welcome in the spring garden, but so too is the foliage form, which creates lovely contrast amid a variety of bulbs. Lavender-blue blooms appear in June, and they carry a scent that is one of the great perfumes of spring. As the season progresses, the yellow variegation in the foliage shades to cream, like shifting light in the garden.
Phlox ‘Blue Paradise’
The first leaves of this favorite Phlox emerge green suffused with deep maroon in a colorful celebration of the start of spring. By summer, stunning flowers open in shades of blue and purple that change with the light of day. In the morning and evening hours, the flowers are deep blue. At midday, they change to purple. This favorite of Dutch landscape designer Piet Oudolf also attracts hummingbirds and butterflies. It’s beautiful planted with Ornamental Grasses or amid the feathery foliage of Amsonia hubrichtii.
Start the spring color show early in your garden with a variety of early blooming perennials, shrubs, and trees. From Witch Hazels, which blossom in late winter, and Hellebores, which generally flower before the last of the snow has melted, to Virginia Bluebells, Brunneras, and Magnolias, there are countless ways to incorporate a rainbow of rich colors into your spring planting schemes. What better way to celebrate the arrival of a new growing season?
The best antidote to winter is a planting of Witch Hazels. This genus of 5 species of upright, spreading shrubs or small trees provides the first big display of color, beginning in late February or early March and continuing for 6 weeks or more depending on the season (the flower petals sensibly curl up if the temperatures plummet). For an even earlier display, cut some branches in January and force them into bloom indoors. Plants thrive in average, well-drained soil.
We love Witch Hazels for the color they bring to winter gardens and for their hardy, problem-free nature. ‘Jelena’ is a favorite, with large ribbonlike petals that gleam coppery orange. In autumn, the shrub lights up again as its matte green leaves turn fiery shades of red and yellow.
Hellebores are considered aristocrats of the woodland garden. Native to Europe and western Asia, the genus contains about 20 species of perennials that bloom in early winter in mild climates and in late winter or early spring where the soil freezes hard, which makes them either the last or the first flowers in the garden. In our gardens here at the farm, they are among the first plants to bloom, bringing a splash of color to the late winter garden, sometimes blossoming amid the last of the snow. They require a moist but well-drained site under the shade of trees. Take care to amend the soil with plenty of organic matter, such as well-aged leaf mold and compost. You’ll be rewarded with long-lived, deer- and vole-resistant plants that will spread nicely on their own.
Hellebore Gold Collection® ‘Madame Lemonnier’ is a large-blossomed beauty that was discovered by a gardener in Normandy, France, where her passion for growing Hellebores turned into a full-fledged hybridization program. The plant’s 3″ upfacing blooms are rich purple red, and are held above lush green foliage on tidy, clumping plants. Under greenhouse conditions at the nursery, many of these impressive blossoms exceeded 4″. A magnificent addition to shade gardens.
It is impossible to live in a northern climate and be unfamiliar with Forsythia. The durability, vigor, and abundant yellow flowers of this early bloomer make it one of the most popular and important ornamental plants known. Forsythia Show Off® is perfect for a tight hedge or a specimen in a border. From France comes this compact variety whose golden flowers are brighter, larger, and stacked closer along the stems from soil to tip. Another bonus is the dark green foliage.
Magnolia is a genus of over 100 species of trees and shrubs widely distributed from the Himalayas to East Asia and in the Americas. Introduced Japanese and Chinese species and their hybrids, such as the showy white Star Magnolia and the pink Saucer Magnolia, draw the most attention in spring. The handful of species native to Eastern North America include the magnificent, evergreen Southern Magnolia (M. grandiflora), Sweet Bay (M. virginiana), and the large Cucumber Tree (M. acuminata).
Magnolia ‘Genie’ is a fairly compact variety, growing 12–15’. In early spring, lightly fragrant, 6″ cupped blossoms appear on slender branches, like goblets of burgundy. A second, lighter flush of bloom arrives in midsummer when provided with full sun and adequate moisture. Bred in New Zealand, this slender, well-branched variety blooms for a longer period, even when young. An ideal small tree to feature alone, in pairs, or to put the finishing touch on a mixed border.
A friend of ours once referred to this charming plant as “prompt” because of the way its beautiful silvery green leaves break ground quite early in spring. They’re followed by a haze of tiny azure flowers, which give this plant one of its nicknames, False Forget-me-not. (It’s also sometimes known as Siberian Bugloss and Heartleaf Bugloss.) Brunnera is most at home in woodlands or along shady stream beds, where it will form a lush understory of quiet beauty. Brunnera ‘Jack Frost’ is a standout variety with frosted leaves veined and outlined in green. The plants grow to 12″ tall and as wide, and while the blossoms provide a fleeting show, the foliage looks superb all season long.
Everyone loves Virginia Bluebells (M. virginica) for their sapphire blue flowers on 18″ stems that gleam from shady spots in April and May, making them an ideal underplanting for shrubs and trees. Plants thrive in deciduous shade and moist soil, where they will seed themselves to create a charming colony.
Trilliums are spring-blooming wildflowers much prized by woodland gardeners for their delicate, 3-petaled flowers and distinctive foliage. Trillium grandiflorum ‘Flore Pleno’ is an exquisite double form that produces pure white flowers in April and May, which will enchant you and all visitors to your garden.
Tall Bearded Irises invigorate summer gardens with their rainbow of colors. You’ll find nearly every shade or color combination in this beloved group of June-Blooming plants named for Iris, the Greek goddess of the rainbow. The sculptural qualities of their elegant blossoms and sword-like foliage are important design elements in perennial borders. Fragrance is often an overlooked quality, yet their perfumes are sweet and pervasive.
Flowers appear sequentially on buds spaced along the stems, which should be cut down to the base after blooming is finished. Reblooming Iris will send up new fans that develop flower spikes as they mature later in the season, giving you a second display of showy flowers after many other perennials have passed their prime. Give them a light dose of fertilizer after the first bloom and regular watering when the things get hot.
Bearded Irises are generally easy to grow. Provide full sun to very light shade and well-drained soil. Add sand if your soil is heavy and plant so that the top of the rhizome is above the soil line. Few pests bother them, except for the Iris borer. Ward off that problem by keeping the soil around plants free of weeds and, in fall, do a thorough cleanup around plants because the borer eggs overwinter in plant debris.
Asclepias tuberosa, our native Butterfly Weed, has long been a favorite in the borders, beds and meadows here at the farm. In recent years, it’s attracted significant attention as an essential source of food for Monarch butterflies who feed on it during their larval stage. (For more information about its role in sustaining Monarchs, visit the website for the Xerces Society for Invertebrate Conservation.)
We have long encouraged plantings of Asclepias tuberosa (pronounced uh-sklee’pee-us) because, in addition to providing food for Monarchs and nectar for a wide variety of pollinators, it’s a boldly colorful bloomer that provides four seasons of interest in the garden. Hardy in zones 4 through 9S and 10W, it grows a modest 1- to 2-feet tall, making it ideal for the edge of the border. The plants produce clusters of brilliantly colored, nectar-rich orange blooms from July through September. (Asclepias tuberosa ‘Hello Yellow,’ an enhanced native variety, grows 2–to 3-feet tall and produces yellow flowers.) These plants shrug off drought, do well even in poor soil, and are deer resistant.
As autumn arrives, Asclepias tuberosa’s seedpods add interest to borders and beds. The slim, decorative pods are filled with papery seeds. As the season progresses, the pods split open, and the seeds, which are attached to silky white parachutes, scatter in the wind. The plant’s pale, empty husks remain, and as winter settles in, the pods look magnificent coated in frost and then in swirling snow. The winter beauty of this plant is not lost on Dutch designer Piet Oudolf who included Asclepias tuberosa in his design for New York City’s High Line.
A 2014 post on the Friends of the High Line blog notes: “The intricate flowers [of Asclepias tuberosa] are stars of the garden in the summer, but the empty husks of the seed pods remain an integral part of the winter garden as well. These oblong golden-gray husks are dry and slightly twisted, warped from the process of drying out. The outsides are rough and gray, with a hint of gold when the light is right. The insides are soft white, reminiscent of the silky hairs that caught the wind and carried the seeds away. These pods crown the remnant skeleton of the stem, providing a subtle, textural beauty during the deep cold of winter. These structures remind us that to High Line planting designer Piet Oudolf, ‘the skeletons of the plants . . . are just as important as the flowers.’ ”
When planting Asclepias tuberosa, be mindful of a few things. It grows best in full sun and well-drained soil (sandy soil is ideal; clay and heavily enriched soils are not). After planting, water the plant deeply then hold off until you see it begin to wilt a bit. If your Asclepias tuberosa develops yellow, chlorotic-looking leaves, it’s an indication that you’re over-watering.
Since some perennial Milkweed varieties are among the last to emerge from dormancy in spring, you might want to mark their location so you don’t plant something on top of them.
Design-wise, as with many additions to the garden, Asclepias tuberosa is most effective planted in clusters of three or more. To create an eye-popping contrast of colors and flower forms, showcase the bold bright orange blossoms alongside the deep purple flower spikes of Salvia ‘May Night’ and Liatris ‘Kobold.’ For a tone-on-tone effect, our head gardener has planted orange-flowering Asclepias tuberosa amid a sea of other orange bloomers such as Zinnia ‘Profusion Orange,’ Echinacea Butterfly™ ‘Julia,’ Butterfly™ ‘Postman,’ or Prairie Pillars™ ‘Flame Thrower,’ and Helenium ‘Short ‘n’ Sassy.’ In meadow gardens, the orange flowers pair beautifully with ornamental grasses including the 18”–30” Pennisetum ‘Hameln’ and the blue spiky foliage of Festuca glauca Beyond Blue™. They’re also a terrific companion for Amsonia hubrechtii, which has green needle-like foliage that turns into a cloud of yellow in fall.
Be aware that Asclepias tuberosa does not appreciate being moved once it’s settled in. The plants produce deep taproots that are better left alone once planted, so site it with care, let it be, and enjoy all of the benefits of this tremendously valuable plant.
Peonies are one of the great glories of the late spring garden. The silky soft, colorful, often fragrant blooms have a natural opulence that make them as treasured in the garden as they are in vases in the house. The gorgeous blossoms are produced by remarkably carefree and robust plants that require almost no maintenance and take twitchy spring weather in stride. In addition to producing lovely flowers that are superb for cutting, the value of their foliage should not be overlooked. In the early spring garden, the reddish-green stems of emerging herbaceous peonies make a fine companion or backdrop for daffodils, tulips and other early spring arrivals.
Planting and transplanting peonies of all types should be undertaken with a bit of care. Click theses links to find all the advice you need along with helpful tips for planting and growing herbaceous and tree peonies.
To help choose the right peony for your garden, start by familiarizing yourself with the different types. Here are three of the most common:
These long-lived perennials range from exquisitely delicate singles to large and lush doubles, with shades from pure white to the deepest red. Here in Connecticut, they usually produce their display in June, and their glossy, deep green leaves look good all season. Peonies make superior cut flowers, lasting more than a week if cut in full bud.
An important thing to understand about Herbaceous Peonies is that they die back to the ground in winter and send up new growth in spring. For this reason, they’re generally classified as perennials. (Tree Peonies, see below, have woody stems that retain their structure year-round, so they’re classified as shrubs.)
A cross between Herbaceous and Tree Peonies, these plants generally blossom between Tree Peonies, which are first to blossom, and Herbaceous Peonies. By planting Intersectional varieties, you extend the Peony blossom season in your garden, creating a continuous flow.
In its native China, the Tree Peony (Paeonia suffruticosa) ranks as a national favorite, and it’s easy to see why. These hardy shrubs produce exquisite floral displays, with silky blooms measuring up to 10” across in May and June.
Tree Peonies are woody plants that retain their structure year-round. Slow to mature, don’t be surprised if there are few or no flowers the first spring after planting; plants generally take a few years to settle in and bloom heavily, but mature plants reach 4–5’ and bear up to 50 showstopping blooms. Deer and disease resistance add to their appeal.