Karl Foerster: the Plant, the Myth, the Legend

You’ve undoubtedly noticed a tall, vertical grass, planted en masse, swaying in the wind at the entrance to the mall, in your neighbor’s yard, or most likely, at the Chicago Botanic Garden.

Feather reed grass (Calamagrostis × acutiflora ‘Karl Foerster’) has, for good reason, become a staple in perennial gardens.

Calamagrostis x acutiflora 'Karl Foerster'
Calamagrostis × acutiflora ‘Karl Foerster’ by Daryl Mitchell from Saskatoon, Saskatchewan, Canada [CC BY-SA 2.0], via Wikimedia Commons

This hybrid of two species native to Europe and Asia can thank German nurseryman Karl Foerster (1874–1970), for discovering the species in the 1930s along a railway in Germany. It is reported that he pulled the emergency brake on the train he was riding in order to collect the plant. The cultivar ‘Karl Foerster’ was named to honor him.

Karl Foerster, son of a painter and an astronomer, was well known for his unique and innovative plant selections at his nursery in Potsdam-Bornim, Germany. The nursery focused on breeding hardy perennials from all over the world. Foerster successfully bred approximately 370 crosses, with a particular interest in clumping grasses, Delphiniums, and Phlox. Originally propagated at Foerster’s nursery, Rudbeckia fulgida var. sullivantii ‘Goldstrum’ is another perennial that remains popular today. Foerster’s nursery endured difficult times over the years yet managed to survive the Great Depression and World War II, during which he is said to have employed Jewish friends despite the risk. As a plant breeder and garden designer, Foerster helped to popularize the use of grasses in garden design and heavily influenced the “New German Garden Style” which focuses on low-maintenance gardening and four-season interest. Those concepts continue to be popular in garden design today. 

Two more modern-day revolutionaries in the field of landscape architecture are Wolfgang Oehme and James van Sweden. Both were inspired and influenced by Karl Foerster. In his book Gardening with Nature, van Sweden remarks “Foerster’s great contribution was to make plants the most important element of the garden, especially perennials and grasses. He was highly sensitive to seasonal variations and promoted the garden as a place of learning.” With inspiration from the arts, travel, and the influence of other garden styles, Oehme and van Sweden pioneered the “New American Garden Style.”

Mimicking the American prairie, this dynamic gardening style blends both native and cultivated plants with a goal of low maintenance. One can easily see similarities to the “New German Style.” At the Chicago Botanic Garden, Evening Island was designed by Oehme, van Sweden & Associates landscape architecture firm and is representative of the “New American Garden Style.” Sweeps of perennials and grasses weave harmoniously through the landscape of Evening Island, softening the transition between the formal gardens of the main island and the native Dixon Prairie. With perhaps a nod to the past, Calamagrostis × acutiflora ‘Karl Foerster’ is a favorite of Oehme and van Sweden and in my opinion one of the stars of the Evening Island plant palette.

View of the landscape design of Evening Island, designed by Oehme, van Sweden & Associates.
Sweeps of perennials and grasses weave harmoniously through the landscape of Evening Island.
View of the landscape design of Evening Island, designed by Oehme, van Sweden & Associates.
Sandy-colored Calamagrostis × acutiflora ‘Karl Foerster’ is a cornerstone of the landscape design by Oehme, van Sweden & Associates.

The most notable characteristic of Calamagrostis × acutiflora ‘Karl Foerster’ are the 5-foot flower stems that tower over a shorter but dense clump of narrow leaves. Purple-tinged plumes of flowers emerge in late spring and as the seeds (which are sterile) mature, the flower stalk turns a sandy color by fall. The seed stems continue to act as a vertical accent through the winter months making it truly a four-season plant. While full sun and well-drained soil with adequate moisture are ideal, this plant can tolerate some shade and heavier clay soils. However, you will see fewer flowers and floppier foliage with more shade. Drifts of this clumping grass are reminiscent of a field of wheat dancing back and forth in the wind. Interrupting the sweeps of grass with a pop of color from another perennial such as Leichtlins’ lily (Lilium leichtlinii), Russian sage (Perovskia atriplicifolia), or purple coneflower (Echinacea purpurea) will add an element of surprise to the garden. While planning your garden for this year, take a leaf out of Foerster’s book and give Calamagrostis × acutiflora ‘Karl Foerster’ a try! 

Sources:

Reimann, Dorothy. “Herr der blühenden Gärten.” Monumente, June 2005, https://www.monumente-online.de/de/ausgaben/2005/3/herr-der-bluehenden-gaerten.php?seite=1#.WldsJK6nGUl (accessed January 23, 2018).

Rettig, Larry. “Karl Foerster’s Lasting Imprint on the World of Horticulture,” Cubits.org (blog), April 26, 2010, http://cubits.org/articlesongardening/articles/view/325/.

Van Sweden, James. Gardening With Nature: How James van Sweden and Wolfgang Oehme Plant Slopes, Meadows, Outdoor Rooms & Garden Screens. Random House Gardening Series, 1997.


©2018 Chicago Botanic Garden and my.chicagobotanic.org

Gardening in Winter: Dos and Don’ts

Welcome to winter, one of the best seasons for gardeners. You have time to plan, prune, and enjoy those houseplants that don’t get much love during the outdoor growing season. Make the most of your winter gardening with these dos and don’ts from Chicago Botanic Garden experts.

DO prune your deciduous trees. From mid-November to mid-March, it’s much easier to prune because you’ll be able to better see a tree’s branching structure and there is less chance of transmitting diseases from one plant to another.

Winter is the perfect time to prune deciduous trees or remove nuisance buckthorn.
Winter is the perfect time to prune deciduous trees or remove nuisance buckthorn.

DON’T prune conifers. Needled evergreens can be pruned in late winter or early spring, before growth begins. Arborvitae should be pruned during spring and early summer.

DO water newly planted trees and shrubs that might be in the path of salt spray from salted roads during periods of winter thaw. Consider wrapping vulnerable trees to prevent damage from salt and extreme temperatures.

DON’T overwater houseplants. Because of shorter days and reduced humidity, most houseplants aren’t in an active growth phase, so they’ll require less water and fertilizer.

DO keep houseplants away from cold drafts, radiators, hot air vents, and cold windows. Plants growing in sunny east- or north-facing windows may benefit from being moved to a southern or western exposure for winter.

DON’T try to remove ice or snow that has frozen onto your outdoor plants. You might inadvertently damage them. Let it melt off on its own.

DO start to plan your garden for the new year. Order seeds and bulbs during the winter so you’ll be ready to plant in the spring.

Ornithogalum 'Chesapeake Snowflake'
Ornithogalum ‘Chesapeake Snowflake’

Get more indoor and outdoor plant care tips with our monthly plant care checklists.

 


©2018 Chicago Botanic Garden and my.chicagobotanic.org

Following a tantalizing trail of wildflowers

Why did five Midwestern horticulturists hike through the oak-hickory forests of the Missouri Ozarks? And why did we need a desiderata? The first question is easy—we were on the trail of specific wildflowers and woody plants to preserve and add to our collections.

Collections trip horticulturists Mike Jesiolowski, Tom Weaver, Josh Schultes, Kelly Norris, and Steve McNamara
Collections trip horticulturists Michael Jesiolowski, Tom Weaver, Josh Schultes, Kelly Norris, and Steve McNamara (left to right)

In a trip funded by the Plant Collecting Collaborative (PCC), a consortium of public gardens, Tom Weaver (horticulturist, Dwarf Conifer Garden) and I (senior horticulturist, Entrance Gardens) joined Kelly Norris (the trip leader) and Josh Schultes of the Greater Des Moines Botanical Garden, along with Steve McNamara of the Minnesota Landscape Arboretum. Before we left, our desiderata—or essential list of desirable plants we would target—was developed, based on what plants our gardens deemed important for conservation, to fill a gap in our collections, or add beauty to our display gardens. And of course, we had the proper state and federal permits in hand for seed collecting. The six areas that we explored were typically oak-hickory forests, which opened up to rocky-soiled glades and provided for plentiful opportunity for collecting wildflowers. With an eye for distinct plant material and genetic diversity, we roamed through the uneven Ozarks terrain, but we weren’t tied to our wish list—we also found a couple of surprises.

Glade opening at Roaring River State Park
Glade opening at Roaring River State Park

Since seed-grown plants are reproduced sexually through pollination, via wind or insects/animals, they are genetically variable. A variety of genes can give each plant the best chance to exhibit a specific phenotype, or physical appearance, and better adaptability to survive pests and diseases. Where seeds are collected could have significant implications on whether a plant can survive in a given environment or not. For instance, we collected seeds of Echinacea paradoxa (yellow coneflower) from its northern most growing region, in Ha Ha Tonka State Park in Missouri. Selecting seeds of Missouri provenance gives this wildflower a better chance of survival in our region, rather than if the seeds had been collected in Texas. Plants that have a different phenotype from what we commonly observe in northern Illinois were of special interest to us. Fruit from Diospyros virginiana (common persimmon) was collected on a 4-foot-tall tree in Mark Twain National Forest because it is unusual to see fruit on a tree of such short stature. In a similar fashion, Symphoricarpos orbiculatus (coralberry), was collected from the Big Buffalo Creek Conservation Area, after we all remarked at the stunning ornamental quality of the fruit display.  

Yellow coneflower (Echinacea paradoxa)
Yellow coneflower (Echinacea paradoxa)
Persimmon (Diospyros virginiana)
Persimmon (Diospyros virginiana)
Josh Schultes examines some holly (Ilex decidua) for collection.
Josh Schultes examines possumhaw holly for collection.

In some cases, we came across desirable plants, but they had already dropped their seed for the year, or simply didn’t produce any due to drought-induced stress. With the aid of GPS, we marked these areas so future explorers to the Ozarks are aware of these plants for their potential collections. For example, Boyce Tankersley, the Chicago Botanic Garden’s director of living plant documentation, was a part of a team that collected in many of these same areas in 2005; their field data was helpful in our search.

Dotted blazingstar (Liatris punctata)
Dotted blazingstar (Liatris punctata)

Although the Ozarks region experienced a late-summer drought that negatively impacted seed production in some instances, we were still able to make 71 collections from October 12 to 16. Our seeds will be grown in our plant production greenhouses. Once they achieve a certain size, they will be distributed to PCC members and planted in the Garden. I am ecstatic to cross Liatris punctata (dotted blazingstar) off the desiderata for use in my gravel garden project in parking lot 1. The seeds we collected should be ready to plant in these beds in two years.


©2017 Chicago Botanic Garden and my.chicagobotanic.org

The Gift That Keeps on Giving: Holiday Plants

Looking for a feel-good, beautiful, reasonably priced gift? Plants are all that and even on trend—see #plantsmakepeoplehappy; it’s an Instagram thing. Here’s a quick guide on which plants to buy—as a gift or for yourself. Make sure to get them to their destination safely by wrapping them head to toe at the store and getting them back indoors as soon as you can.

Holiday plants come in all shapes, sizes, and colors. Take the beautiful but dreaded poinsettia. It’s beautiful because the red, cream, or sparkle-laden plants are dazzling. But it is also dreaded because the plant will drop its leaves in warm and dry air, cold drafts, or direct sunlight. There’s hope—and you need not be a horticulturist to nurture a holiday plant.

Christmas Cactus

Christmas Cactus
So much for common names—these colorful plants (Schlumbergera spp.) hail from Brazil’s rainforest. Place them in bright, indirect light. Water thoroughly, letting the soil dry a little between waterings.

Rosemary

Rosemary
Who doesn’t love a fragrant pot of rosemary, trimmed to look like a miniature spruce tree? Keep it moist but not sopping wet, and give it bright light or a sunny window. And snip some stems for your culinary adventures.

Orchid

Orchid
Forget to water? No problem. Overwatering orchids kills them faster than underwatering. Place them in a southern or eastern exposure and enjoy several months of bloom.

Poinsettia

Poinsettia
Give it a cool spot out of direct sunlight and keep the soil moist but not soggy. It’s tricky to keep poinsettias going until spring, but if you’re game, here’s how.

Amaryllis

Amaryllis
Breathtaking, beefy amaryllis blooms—trumpets of white, cream, red, pink, or multi-colors—put on a show for several weeks. Put the plant in a bright, sunny spot and water thoroughly, letting the soil dry a bit between waterings. As each flower fades, remove the flowering stalk. A bonus: you can get it to rebloom next year.

Cyclamen

Cyclamen
Often called “the poor man’s orchid,” cyclamen (SIKE-la-men) plants like it cool, preferring daytime temperatures around 68 degrees Fahrenheit and down to 50 degrees at night—not always easy to do. However, an unheated sunroom, enclosed porch, a bright, cool window or an east or north-facing windowsill will do. Set the plant pot in a bowl of water and let it “drink” up the water and then return it to the saucer. Soil should dry out a bit between waterings, but not so much that the leaves begin to wilt.

Greenhouses

Need a little holiday pick-me-up? Stop by the Garden’s Greenhouses in the Regenstein Center for a peek at the stunning holiday plants. Save time to drop by the Garden Shop for a selection of plants and other holiday gift ideas.


Guest blogger Nina Koziol is a garden writer and horticulturist who lives and gardens in Palos Park, Illinois.


©2018 Chicago Botanic Garden and my.chicagobotanic.org

Three easy, harvest-inspired Thanksgiving centerpieces

With just a bit of effort, you can make your holiday table warm and inviting—and a worthy backdrop for your meal.

Nancy Clifton, former program specialist at the Chicago Botanic Garden, shared some easy, crafty ideas harvest-inspired centerpieces.

A Festive Look

Here’s how you can make Thanksgiving-themed floral centerpieces like a pro:

Thanksgiving Flower Arrangements

Thanksgiving Flower Arrangements

Pick flowers in autumn colors. Buy a few bunches of flowers in different fall colors and textures. Nancy chose red roses, yellow mums, red-yellow mums, and hypericum berries to give the arrangements some variety.

Paint Thanksgiving mason jars. If you want to up your Thanksgiving game, paint your vases in holiday colors such as brown, orange, and ivory. Nancy used craft paint on mason jars, and sanded the lettering on the jars to give them a vintage look.

Save time by measuring flowers. Nancy’s time-saving hack is to trim one flower with pruners and remove foliage at the bottom of the stem. Place that flower in the mason jar vase. If you’re happy with the height, remove the flower and use it as a measuring tool to trim the rest of your flowers.

Fancy Pumpkin Planters

Add a natural look to your table with pumpkin succulent centerpieces. The best part? You can repurpose and eat parts of them when you’re done.

See the demo video on YouTube here.

Thanksgiving Centerpiece
The finished succulent and squash centerpiece

Gather the basic tools and ingredients. Grab a hot-glue gun, reindeer moss, and floral picks. Gather small- and medium-sized pumpkins (you will want several), a succulent container, bunches of kale, and cabbages.

Assemble the planters. Cut the ends off of your succulents so they have a flat base, and set them aside. Adhere moss to the top of your medium-sized pumpkins with your hot-glue gun. Once the glue is dried, add the succulents on top of the moss, and adhere with hot glue or floral picks.

Arrange your centerpiece. When the pumpkins are dried, place them in the center of a large decorative tray. Add smaller pumpkins, bunches of kale, and cabbages to tray, arranging them in a bountiful display. You can even paint the stems of your small pumpkins with glitter-paint to give them extra-fancy glitz.

Add an intimate glow

Improvise! Try adding pumpkin planters, candles, and string lights to the centerpiece to bring a warm, enchanting feel.

Find more of Nancy’s ideas, check out her 101 on creating Thanksgiving cornucopias.


©2017 Chicago Botanic Garden and my.chicagobotanic.org