Monthly Archives: January 2017

Asclepias tuberosa: Essential Monarch Food & a Whole Lot More

January 26, 2017Perennials, plants for pollinatorsDebWFF

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.)

This year, it was named the 2017 Perennial of the Year by the Perennial Plant Association.

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.

ASCLEPIAS TUBEROSA (YELLOW FORM) — Asclepias tuberosa ‘Hello Yellow’

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.

milkweeds-022-620x416_deborah-silver — Milkweed pods. Photo courtesy of Deborah Silver of Deborah Silver and Co.

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.

Asclepias tuberosa, zinnia zowie — Create a tone-on-tone palette by planting Asclepias tuberosa with other orange-flowering plants including Zinnia ‘Zowie! Yellow Flame.’

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.

Liatris spicata Kobold, Stokesia, Asclepias tuberosa — Asclepias tuberosa with the purple flower spikes of Liatris spicata ‘Kobold,’ and the deep lavender blossoms of Stokesia (more commonly called Stokes’ Aster).

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.

Cheating Winter – The Bulbs Take Root

January 18, 2017Bulb ForcingDebWFF

Last autumn, did you take our advice and pot up some bulbs for indoor forcing? We hope so! Here’s an update on how some of our potted bulbs are doing, and it provides plenty of how-to tips for anyone who might like to try this:

After we potted bulbs in late October, we put them in an outdoor shed. The shed is unheated (in Zone 5), but it’s attached to the house. We covered the bulbs with a couple of old flannel sheets. This helps modulate the temperature while keeping the bulbs in the kind of darkness they’d be experiencing if they’d been planted in the ground.

Every 2 to 3 weeks, we’ve been checking the soil for moisture. If the surface feels dry to the touch, we water sparingly.

To ensure the bulbs are kept at the proper temperatures, we placed a thermometer in the storage crate alongside the bulbs. We monitor it regularly to make sure the shed temperatures remain in a range similar to what’s going on outdoors as temperatures drop from fall to winter, but that, ideally, they never go below freezing for an extended period of time.

After about 10 weeks, we begin checking the pots to see if the bulbs have rooted. It’s simple to do. Being careful to hold the soil and bulbs in place, gently turn the pot over and look for roots emerging from the pot’s drainage holes. If roots are visible, the bulbs are ready for forcing. (If there are no roots, leave the bulbs in dark, cool storage.)

To keep a steady supply of forced bulbs blossoming indoors, we bring in only a few pots at a time over 3 to 4 weeks. The rest are kept in the shed until it’s their turn. By staggering the forcing, we enjoy spring flowers inside the house from January through March.

Once the pots are brought indoors, we encourage bloom by watering the bulbs and placing the pots under fluorescent lights in a cool room (below 65 degrees F). (If you don’t have a fluorescent light, put your pot in a sunny, south-facing window.) Depending on what type of bulbs you’ve potted, the blossom show will begin soon. Watch for our results in the next Bulb Forcing post!

(To read the first chapter in Bulb Forcing, click here.)

Staff Favorites for Spring

January 12, 2017New for SpringWhite Flower Farm

Each spring, about a dozen of our staff members participate in plant trials. Each of us takes home flats of annuals, perennials and shrubs that are being considered for addition to our lineup. We grow these plants in our home gardens, and we take copious notes and photos as the season progresses. When autumn arrives, we all have a pretty good idea of which plants live up to their breeder or grower’s claims and which don’t. We also know which have won a permanent place in our gardens.

As you peruse our offerings for spring and examine the new items in our Spring 2017 Garden Book and on our website, you might like to give special consideration to plants chosen as favorites by our staff members. While we asked staff members to name a single favorite, several had trouble narrowing down the choices. The result? We let them cheat a little. After all, what’s the harm? We apply the same logic in our gardens where there’s always room for one more.

Hellebore Gold Collection® Madame Lemonnier

When our Director of Horticulture Rob Storm and our Nursery Manager Barb Pierson both agree on which plant is the most exciting choice for spring, it’s worth taking note!

‘The foliage is dark green, large and vigorous, but the real show is happening right now in our greenhouses. The flowers are very large for a hellebore, over 3” across, and the color is a burgundy pink that is stunning. Looking across the crop, there are flowers everywhere. Madame is a beautiful strong lady!’

– Barb

‘I took a shot of a Madame Lemonnier bloom next to a blossom from Hellebore Gold Collection® Pink Frost, and it is easily double the size, maybe even bigger.’ [That’s Rob’s hand you see in the photo above.]

– Rob

Monarda fistulosa

‘A favorite of mine is Monarda fistulosa. Subtle and more modest in its appearance than newer hybrids, this native Bee Balm is anything but subtle when it comes to attracting pollinators to the garden. The blossoms’ generous supply of nectar draws a steady stream of butterflies, moths, and hummingbirds all summer. (Love watching the dueling acrobatics of hummingbirds as they dive, hover, and defend their favorite nectar source.) In fall, birds visit to feed on the flowers’ dried seed heads. I’m planning to add a few plants to our sunny back hillside and look forward to sitting on the porch enjoying the show.’

– Ann

Tomato ‘Chocolate Sprinkles’

‘Being one who loves chocolate, I was intrigued by the name and color. I was pleasantly surprised by the taste. This is a delicious, small and mighty tomato.’

– Lisa

Heliopsis ‘Burning Hearts’

‘This grabbed my attention from afar in acres of growing fields. Its rich foliage is outstanding and the flowers are so unexpected as they are very large with reflexed petals. Heliopsis are overlooked because they aren’t in bloom during the rush of spring but they can play an important role in the garden as false sunflowers bloom when many home gardens are looking tired. Being a bit taller than the average perennial gives it a commanding stature in a mixed bed of ornamental grasses, Joe Pye Weed, Hydrangea, Liatris and Rudbeckia.’

– Tom

Coreopsis ‘Leading Lady Sophia’

‘A real workhorse in the summer garden, it blooms earlier, which is a big bonus, as well as being sterile so the showy floral display goes on for months. Clean foliage, large, bright flowers, no dead-heading required, compact size and heat tolerance all add up to a great selection for the novice or expert alike.’

– Tom

Hemerocallis ‘Marque Moon’

‘Being a daylily enthusiast, an amateur collector and a garden retailer, I see a lot of daylilies, and I found myself continually impressed with this selection. The ruffles, the diamond-dusted petals, the clean white coloration and the slightest contrast of butter yellow throat and edges really earns this a place in any garden. It has replaced H. ‘Joan Senior’ as my favorite white daylily.’

– Tom

Petunia Tidal Wave® Silver

‘I’m blown away by Petunia Tidal Wave® Silver. Unlike your grandmother’s petunias, which tend to collapse after a rainstorm, this one just keeps coming. In the farm’s display garden, it grew up the base of a tuteur, forming a remarkable wave. At home, it stood up really well for me in containers, blooming its head off all summer.’

– Eliot

Coleus Flame Thrower™ Chipotle

‘My favorite new plant introduction is Coleus Flame Thrower™ Chipotle. In addition to growing it in my garden, I saw it at the trial gardens in containers at Ball Horticulture in West Chicago, as well as at DS Cole’s Open House in New Hampshire. It gives structure and color to mixed annual containers. I like how it plays well with others in color, shape and habit. Apparently I am not the only one who likes it – two of our new annual containers have it as a supporting element, Nectar Depot and Chipotle Spice.’

– Cheryl D

Hummingbird Kit

‘I’m most excited about our Hummingbird Kit. I have several Hummingbirds who visit our backyard each year, and I’m looking forward to identifying them with my new field guide as they take a little rest and perch on my new feeder!’

– Mary

Dahlia ‘AC Dark Horse’

‘I love all Dahlias, and I think it’s absolutely necessary to try new varieties so I can make sure that I am growing the very best ones available. I choose new varieties by going on a garden walk at WFF and taking in the entire Dahlia border (it must be 50’ long). I let my eyes jump to the most stunning of them all, and this year it was ‘AC Dark Horse.’ The color combination is electric, and I am sure it would be a stand-out in any garden, even one that is filled with Dahlias. I am ordering 6 of them.’

– Margret

Cardoon: Cynara cardunculus ‘Porto Spineless’

[Editor’s note: Cardoons are not new to White Flower Farm, but when we reintroduced them last year for trials, they were new to some of our staff members. They might be new to you, too!]

‘I couldn’t resist planting 3 Cardoons in a small and rather pathetic garden bed near the front of my house. I think I have seen them in every English garden I have ever visited or read about, but I could never find them for sale anywhere near me. At the beginning of the summer, they looked like pretty ferns. By the end of the summer, they were about 4’ tall and absolutely amazing looking. At least three neighbors told me that my garden looked “fancy.” Apparently, all it took was 3 Cardoons.’

– Margret

Digitalis purpurea Dalmatian Peach

‘What an attractive plant to brighten the back of a flowerbed.’

– Alyson

Summer Magic Roselily Mix

‘Our mix combines four varieties of fragrant Oriental lilies, each the product of years of selective breeding. The beauty of these blossoms is reason enough to plant them in your garden, but in addition to what you see in the photo, you’ll enjoy a long season of bloom and a rich perfume. Also impressive is the amount of bloom you can expect in the first season.’

– Lorraine

Miltonia Orchids

‘Lots of us grow orchids in our homes. We’re delighted to be able to offer a colorful array of richly patterned, fragrant Pansy Orchids. The name is derived from the patterning on the flowers, which mimics the masklike faces of pansies. Descended from wild orchids found in the cloud forests of the Andes Mountains, Miltonias are a lovely, easy-care addition to any interior, and they’re bound to attract lots of attention.’

– Lorraine

Months of Mini Moth Orchids

‘These delicate mini moth Orchids are so cute! These kinds of Orchids are hard to find, and the colors and patterns on the leaves are so intricate and interesting. You get to try a new one each month. Plus they are low maintenance and tiny, so it’s easy to make room for them.’

– Liz

Lindera benzoin

‘I am looking forward to planting out Lindera benzoin in the gardens here at the farm. As it is a larval host for the Spicebush Swallowtail, I’m hoping to lure in and meet one of those “big-eyed” green caterpillars in person. It’s on my bucket list!!’

– Cheryl K

Jasmine Polyanthum: A Wintertime Treasure

January 3, 2017Indoor Plants, JasmineWhite Flower Farm

In the depths of winter, when the air is cold and dry outside and hot and dry indoors, there is no indoor plant we cherish more than Jasmine polyanthum. This beloved subtropical vine forms a trailing mound of small leaves and curling tendrils. The dark green glossy foliage is beautiful to look at, but it’s the small white flowers and the heavenly fragrance they release that makes this plant such a treasure. The perfume can fill a room, and no matter what the weather outside, it lifts our spirits by conjuring warmer, balmier places.

Keeping Jasmine moist but not soggy is the key to maintaining healthy plants — Keeping jasmine moist but not soggy is the key to maintaining healthy plants.

Our Jasmine plants are grown here in our greenhouses, which are overseen by Nursery Manager Barb Pierson and her staff. They’re shipped to customers starting around mid November and can be shipped through late March, depending on the weather. We asked Barb to talk about Jasmine and to offer a few tips on how to keep these plants thriving through their season of bloom or beyond.

“There are lots of varieties of jasmine,” Barb says. “Confederate Jasmine is the one you see growing down south. It’s not for indoors. Ours is Jasmine polyanthum. You don’t often see it in the landscape. It’s more of a houseplant. Other indoor varieties don’t produce the same number of blossoms. Jasmine polyanthum gives one big flush, which may continue for weeks. The fragrance is in so many perfumes, soaps, candles and infusers. In addition to the fragrance, the vine itself is lovely, delicate yet strong, the dark green leaves spaced along tendrils. The small, star-shaped white flowers stand out against this lush, beautiful background.”

Jasmine production in greenhouse, Sam tending plants — Nursery staffer Sam is an experienced jasmine grower, and she takes superb care of our plants.

Last summer was “super hot,” as Barb puts it, and while Jasmine polyanthum doesn’t like that kind of heat, the plants did beautifully, largely thanks to Sam, the staff member who tends them. “She’s now a seasoned jasmine grower,” Barb says. “She’s been doing it for at least four years, and she doesn’t let them get too dry.”

WATERING

The key to keeping Jasmine polyanthum happy is to give it “steady, even moisture,” Barb says. “If jasmine gets very dry, it doesn’t bounce back. At any point in their life cycle, if you let the plants dry down to where they’re physically wilting, they really don’t bounce back without getting brown leaves and looking awful. These plants like humidity – you can spritz them or use a humiditray.”

FERTILIZER

While some customers keep their jasmine plants and summer them over to encourage rebloom the following winter, the majority (and most of our staff members) treat the plants as winter “annuals,” tossing them out when the bloom cycle is done. If you do choose to keep a Jasmine polyanthum plant going through the warmer months, take it outside in spring once temperatures have settled above freezing, and give it a shady spot. The plant will appreciate fertilizer. “They take a lot of feed,” Barb says. “We use Organic Gem® Liquid Fish Fertilizer, a foliar feed, and they really like that. (Be advised that the smell persists for two days so do the feeding in summer when the plants are outside.) Feed them once per month from April to the end of October. Use a water soluble fertilizer for houseplants, and use it at half the recommended rate.”

TEMPERATURES

In autumn, the plants are cooled naturally. In mid-September, “we begin cooling them to 42 degrees F at night,” Barb says. “This is part of what initiates flower formation. Starting in mid-September, we hope for cool nights, not below 40 degrees F, until mid-October. Then we turn up the heat gradually to 65 degrees F.” The days begin to shorten at that time of year. “That’s probably a trigger, too,” Barb says, “but we have no scientific material to back that up. Indoors, the plants don’t like hot air from radiators or fans blown on them. They prefer shade to bright, indirect sun. They do not like direct sun.

While the fragrant white blossoms of Jasmine tend to get all the attention, we also love the delicate vines, which send tendrils up and out in a cascade of lush green. — While the fragrant white blossoms of jasmine tend to get all the attention, we also love the delicate vines, which send tendrils up and out in a cascade of lush green.

PRUNING

If you summer over your plant, “Stop pruning by August 1 or you will lose blooms,” Barb says.

Jasmine plants in handcrafted Barnsley Bowls_ — Jasmine plants in handcrafted Barnsley Bowls

SHIPPING

“We start shipping jasmine around Thanksgiving when they’re fully budded and ready to begin flowering. We’re sometimes delayed if the fall is warmer than usual,” Barb says. “They can take the upper 20s in temperature so shipping continues, but we try not to ship after it’s below freezing.” If the box is left on someone’s front stoop for hours, the buds will fall off.

“They like 40 degree to 50 degree cool weather, and the flowers last longer in cooler temperatures. A cooler room of the house with bright indirect light is ideal.”