In fall the Instagram feeds of many of our favorite gardeners, quite understandably, start to wither or move indoors. Not so that of Dutch garden designer Frank Heijligers. Indeed, much like the dames of imperial Russia, who, rather that retreating from the cold, donned furs and tiaras in anticipation of the social high season, Frank’s winter garden seemed to reach the height of its sparkling charm.
Enchanted, we decided to ask Frank, who grows grasses, perennials, trees, and shrubs at his nursery, Plantwerk, to divulge his secrets for a successful winter garden. Here are his nine tips for adding sparkle and moody color:
Above: Now a dramatic black, the once purple cones of Agastache ‘Black Adder’ still stand tall in the frosty winter garden.
“Successful winter gardens need a lot of plants with good structure in them,” says Frank. “The plants have to be strong and have more than one interest: nice foliage, bloom, color, seed head, change of color in fall, strong skeleton in winter.”
Showcase long-lasting seedheads.
Above: Like spectators at the ballet, crowds of Monarda ‘Croftway Pink’ seedheads watch a changing fall landscape.
Fill the gaps.
Above: Because plants with good structure tend to bloom later, Frank notes that the successful four-season garden “starts with having a little more patience in spring.” To fill in the gap, he uses bulbs. Alliums, which maintain a sculptural seed head after they have gone by, are a good choice. Above: One of Frank’s gardens in summer. Though lust and leafy, it still maintains a textured feel.
Consider frost-proof plants.
Above: A similar border garden in winter, when the regal heads of Phlomis take on a silver sheen.
“Hosta or Alchemilla mollis are plants that look good early on in the year, but with the first bit of frost, they collapse,” Frank says. “You need plants like Phlomis, Aster, Eupatorium, Veronicastrum, and Anemone combined with grasses like Deschampsia, Miscanthus, Sporobolus, and Festuca mairei to make the garden look good until March.”
Above: Another sculptural favorite: Veronicastrum ‘Pink Spike.’
Bonus: Birds love all the leftover seedheads in Frank’s hibernal garden.
“I don’t do frilly,” say Diane Schaub, director of gardens at Central Park Conservancy. We are standing under the shade of an old magnolia in the English garden, one of three smaller gardens within Central Park’s six-acre Conservatory Garden near the northeast corner of the park. Schaub, who earned a diploma from the New York Botanical Garden’s School of Professional Horticulture, has been curating the Conservatory Garden for more than 30 years. And while she does not do frilly, she does do color and texture, breathtakingly well. She has a painter’s eye for composition and an architect’s instinct for structural detail.
Below, we share her best color combinations for fall garden beds:
Above: “This is as frilly as I go,” she clarifies, indicating a velvet-leafed plant with burgundy leaves, beside the bluestone path. The plant in question is a Solenostemon (formerly classified as Coleus) and the cultivar is ‘Lancelot.’ Above: Solenostemon ‘Lancelot’ (paired with Salvia ‘Paul’) belongs to a crew of leafy annuals whose impact is felt dramatically in this garden, where the seasonal spectacle owes a great deal to plants whose interest lies in their foliage.
Purple + Yellow + Blue
Above: If you thought leaves were boring, think again. Solenostemon ‘Purple Prince’, black-leafed Dahlia ‘Mystic Illusion’, and Salvia farinacea ‘Victoria Blue.’
Above: A bed of Pennisetum setaceum ‘Rubrum’, Salvia x ‘Indigo Spires’, the leafy and lilac-striped Strobilanthes dyeranus, and elephant-eared Colocasia esculenta ‘Blue Hawaii’. The latter “makes the whole composition work,” says Schaub. Dark purple Pennisetum ‘Vertigo’ is in the background. Above: The English Garden is arranged in beds radiating from a central pond overhung by the largest crabapple tree in Central Park, leaves now turning yellow. Designed by Betty Sprout and opened in 1937, this part of the park was by the 1970s considered one of the most dangerous places in New York City. In 1980, the Central Park Conservancy was formed in response to the neglect the park had suffered in the previous two decades. Its founding director, Elizabeth Rogers, earmarked the Conservatory Gardens for renovation.
I love this plant for its unique flower and even more unique seed heads that look fantastic added to dried flower arrangements. In mild climates, direct-sow the minuscule black seeds onto well-drained soil in a sunny or mostly sunny spot, and then keep the soil consistently moist. Love-in-a-mist seeds require light to germinate, so be careful not to cover them up when planting. Bonus: these seeds readily re-seed in my garden every year.
Nasturtium (Self-Seeding Annual)
Above: Photograph by Marie Viljoen.
Another easy-to-grow favorite. I adore how nasturtiums effortlessly scramble about the garden and pump out colorful flowers and lily pad-like leaves. These hardy annuals prefer a sunny spot, tolerate poor soil, and grow well in containers or trailing from raised beds. Some gardeners recommend soaking and scarifying these hard seeds for better germination, but I’ve never done that and have had total success. I encourage my nasturtium family to come back year after year by re-scattering the seeds upon pruning them back.
Above: Photograph by Britt Willoughby Dyer for Gardenista.
Every year I grow some hollyhocks from seeds saved from last year or acquired from generous friends and family. Not to be blasé, but I generally just throw theses flat seeds about at the end of fall, all willy nilly. But I suppose the “proper” way is to sow them a week before last frost at just ¼ inch deep and about 2 feet apart. I find that hollyhocks thrive in a sunny to partly sunny spot. Too much shade and they bloom way less and lean too much. Also know that most hollyhocks are biennials, meaning the first year the plant just puts out leaves and then flowers the next year.
Iceland Poppy (Annual in Warm Climates; Perennial in Cool Climates)
Differing from California poppies due to native origin, use, and flower type, Iceland poppies thrive in cool temperatures, appreciate regular water, and their papery translucent flowers are great for adding to arrangements. You can get a head start on your cutting garden by planting these seeds about four to six weeks before your average first fall frost, or in early to mid-fall in milder climates. Plant the tiny seeds in a sunny spot in well-draining soil and remember not to cover the seeds as they need light to germinate. Theses poppies can be slow to germinate, so be patient. I especially like the Champagne Bubbles mix.
By now I’m sure you know how critical milkweed is to the survival of the monarch butterfly as it is the only plant the caterpillars will eat. Help our winged friends and put these seeds on your late fall planting list. After the first frost, scatter seeds directly on the soil surface in a sunny, well-drained location, and then press them lightly into the soil. If the ground gets dry, lightly water the seeds. Just be sure to choose a milkweed that’s native to your area. Why? Planting non-native types of milkweed risks the health of the butterfly.
When August melts into September, nights are suddenly noticeably longer, while flowering perennials seem to grow wilder, to compensate. One of the greatest gardening pleasures of this cusp-season is the effusion of a tousled collection of native plants whose flowers are the languid counterpoint to spring’s cheerful bursts of blossoms. If we must have winter, then these sultry blooms are a fitting way to celebrate the dying of the light. Here are 11 native perennials for late summer and fall.
Above: Anise hyssop (with foreground of skullcap), blooms for months, into fall.
Of all the native perennials that bloom late into the year, if I had to choose just one to provide summer-to-fall flowers, it would be Agastache foeniculum and its various cultivars. Tall in stature, with licorice or mint-scented leaves, and profuse little blue flowers, these sun-loving hyssops provide height and bulk and filler, all at the same time. They are also elegantly lanky, and are a day-long buffet for bees, other pollinators, and even hummingbirds. If you can bear it, grit your teeth and cut the waning flowers back in late summer for a late fall resurgence; and leave those flowers to set seed for seed-eating birds like goldfinches.
Asters (Symphyotrichum pilosum, S. ericoides, and others)
Above: Airy white asters sparkle in early fall landscapes.
No late summer garden seems complete without asters—low-maintenance and long-blooming. Heath aster (Symphyotrichum ericoides, above) likes full sun and is hardy from zones 3 to 10. Hairy aster (S. pilosum) can handle more shade and likes moist soil. It is hardy from zones 4 to 8. For woodland gardens, choose wood aster (Eurybia divaricata).
Flowering spurge (Euphorbia corollata)
Above: Flowering spurge is a native Euphorbia.
Clump-forming flowering spurge is one of the native perennials that seems to fly under the horticultural radar. Also known as the baby’s breath of the prairie, it has a loose, breezy habit with wiry stems tipped by flower-like bracts and distinctive, three-celled seed capsules. Flowering spurge pairs well with grasses and golden rods, asters, helianthus, and partridge pea. It flourishes in full sun and is hardy from USDA zones 4 to 9.
Great burnet (Sanguisorba officinalis)
Above: The wine-colored flower spikes of great burnet against a backdrop of Rudbeckia.
Great burnet is potentially statuesque, but it never dominates, visually. Instead, its threadlike stems hold burgundy flowerheads effortlessly aloft, adding tousled lightness to late summer and autumn gardens. Grow great burnet in full sun, and enjoy its cucumber-flavored leaves in salad. It is hardy from zones 4 to 8.
Ironweed (Vernonia fasciculata and other species)
Above: Ironweed beginning to bloom on Manhattan’s High Line.
The vivid amethyst tufts of ironweed are welcome relief from the cheery but often dominant yellow palette of the late summer native garden. Smooth ironweed (Vernonia fasciculata) is hardy from zones 4 to 9 and flowers best in full sun. Giant ironweed (V. angustifolia) grows better in partial shade, and is hardy from zones 5 to 8. Both species require ample moisture.
This is part of a series with Perfect Earth Project, a nonprofit dedicated to toxic-free, nature-based gardening, on how you can be more sustainable in your landscapes at home.
“We have declared 2024 the year of milkweed,” says Andi Pettis, director of horticulture at Governors Island. For the past couple of years, Pettis and her team have been busy incorporating milkweed into the island’s plantings. They’re focusing on the three species native to the ecoregion: butterfly weed (Pettis’s favorite because of the “incredible variation in color from golden yellow to almost scarlet”), mauvy common milkweed, and hot pink swamp milkweed. Her goal is to finish planting 5,000 milkweed plants this year. “Showing the relationship between monarch butterflies and milkweed is an easy way for us to connect people to the benefits of native plants and show them why it’s important to support wildlife even in an urban environment.” The efforts have paid off. They’ve been noticing more and more monarchs on the island. You’ve heard it before: If you plant it, they really do come. (See Monarch Butterflies Are Nearing Extinction: 5 Ways to Help.)
Planting milkweed is just one of the many initiatives that Pettis and her team are doing to bolster biodiversity. “Climate resiliency and sustainability were sort of baked into the design of the park,” she says. Created by the design firm West 8, with Mathews Nielson Landscape Architects, the park features 120 acres of hills, meadows, and forests in the middle of New York Harbor. “It was a reuse project really—an old military base turned into a public space with new parks,” she said. “But there was no horticulture staff when I was hired [six years ago].” Pettis, who trained at Brooklyn Botanic Garden and had risen through the ranks at The High Line to become director of horticulture before moving to Governors Island, had to build a team from scratch and began to rehabilitate areas where maintenance had been deferred for years. Today, she and her team have introduced 52 native plant species to the island, planted habitat for butterflies and birds, and brought in sheep to tame the rampant spread of invasive species. “We’re working with nature here,” she says. “It’s not a short fix, but it’s working. We’re in this for the long haul.”
Pettis talks about this bustling and beautiful urban island park and shares how they’re bringing biodiversity back. [This interview has been condensed and edited for clarity.]
Photography by Sarma Ozols, unless otherwise noted.
Q: How are you gardening for biodiversity?
Above: Governors Island is doing what they can to help increase the dwindling monarch population by planting milkweed, the insect’s main food source. Here, in the milkweed demonstration garden in Liggett Terrace, several different pollinator-friendly native plants grow together including Asclepias tuberosa (Butterfly weed), Asclepias incarnata (Swamp milkweed), Agastache foeniculum (Anise hyssop), Phlox paniculata ‘Jeana’ (Garden phlox), and Echinacea purpurea ‘White Swan’ (Coneflower).
A: The park was designed for sustainability and climate resilience. West 8 built hills and these kinds of swales and berms to raise part of the park out of the 100-year floodplain. Working with Matthews Nielsen, they created a lot of naturalistic areas based on coastal maritime plant communities and filled the park with a lot of native trees. I think there are 53 different species of native trees planted on the South Island alone!
We have made it clear that we are choosing plants that mimic our coastal maritime shrublands and grasslands native plant communities. We’re also focusing on those that benefit biodiversity and wildlife. In areas where we have managed to retake the land with these native plant communities, we’ve seen huge upticks in the native insect populations.
Q: How are you adapting to our changing climate?
Above: When you walk along the pathways on the 70-foot high Outlook Hill, you’re immersed in plants like the fragrant native shrub Clethra alnifolia ‘Ruby Spice’ (right) and the red fruiting Viburnum opulus (Guelder-rose).
A: As temperatures warm, we are definitely experimenting with plants that would be considered more Southern. For example, we are considering planting live oaks on the island. We are also growing pawpaws, persimmons, and magnolias that are all doing really very well.
Common milkweed pods are a native vegetable that could be as familiar at summer greenmarkets as okra. As a food, milkweed still resides on the foraging fringes, or on rare restaurant menus, despite having been valued by Native Americans in regions throughout its range. Like okra, milkweed pods herald sweltering weather and are ready to harvest when crickets warm up and cicadas begin to zing. While succulent okra originates in Africa, and is grown as an annual crop in the United States, common milkweed (Asclepias syriaca) is a cold-hardy perennial indigenous to eastern North America. It has edible shoots, buds, flowers, and immature pods. And it is one of the most valuable milkweed hosts for monarch butterfly larvae.
Here’s why to plant common milkweed as a vegetable, and how to prepare milkweed pods once you have gathered a clutch.
Above: Warts and all, these tender common milkweed pods are at the right stage for harvest.
Dozens of milkweeds are native to North America. Monarchs, and hundreds of other insects, rely on them all for food. It bears repeating that the species we are discussing as human fare is Asclepias syriaca.
All parts of cooked common milkweed taste like a mild green vegetable, along with a distinctive sweetness. It is never bitter. If you have collected, or grow, a milkweed whose distinctive white sap does taste bitter (raw or cooked), it’s a different species. (Others may be edible, but we are not addressing them here.)
Above: Common milkweed flowers are heavily perfumed.
Common milkweed blooms in early to midsummer. Its plump umbels of blossoms are richly scented and they are edible in their own right, as are the immature green clusters of buds that precede them.
Above: Immature milkweed pods are tender and sweet.
Milkweed pods form about three weeks after a flower has been pollinated. More than the spring shoots or flower buds, they taste uniquely like the scent of the flowers, their flavor coming from the soft white seeds and their pre-silk nestled inside rough, green capsules. While the pods are immature, before the silk has strengthened and the seeds hardened, the entire milkweed pod is edible. (Later, as the capsule toughens, the seed-and-silk cluster inside can be popped out and cooked alone, before the silk becomes tough.)
Above: Tiny pods are good to eat, too. Large ones are fibrous. Above: Common milkweed pods in my previous vegetable garden.
Despite the fact that this striking native plant is beautiful in bloom, supports hundreds of insect species, and is edible from nose to tail (as it were), it remains unusual in cultivation. I have yet to hear of a farmer growing it for the table, but perceptions shift: Ten years ago no one was bringing invasive and edible Japanese knotweed to market, either, and that has begun to change.
Above: A monarch butterfly on milkweed in my previous garden. Their caterpillars feed on the leaves.
