January 2018 – My Chicago Botanic Garden

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.

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.

Does This Houseplant Make Me Look Like an Adult?

Hi, my name is Erica. I’m a bad plant parent.

The irony that I work at the Chicago Botanic Garden is not lost on me. (Please don’t fire me, plant bosses.) The problem is, I have no idea how to take care of plants. Not really.

Erica Masini, blog author and plant parent — I have no idea what I’m doing.

Walk into my apartment and tell me what you see: A wasteland of unsuspecting money trees and innocent spiderworts. A drooping pothos in the corner, desperate for water. Squeezing the life out of my little green pals does not bring me joy. And yet, here I am, a lone wolf among my jungalow-dwelling, millennial peers: A plant-killer.

Raise your hand if you’ve ever asked these questions: Does my monstera prefer direct sun? Will an aloe vera kill my cat? What if I get too caught up in my very important plans (read: binging Mindhunter on Netflix) that I forget to water my fern every day? Why would I even want a plant? (More on that later).

One of my goals is to have more life in my home; to lay down some roots, so to speak (plant-pun intended). And so I invite you to follow along with me as I chronicle my gardening adventures in Plant Parenthood—a blog series about growing a relationship with plants.

With the Garden’s horticulture staff as my guide, I’ll learn the ins and outs of soil, pests, and shade. I’ll make mistakes. I’ll definitely kill more plants.

But along the way, I’ll learn something. And I hope you will, too.

TL;DR? Click here for the “Three Things Every New #PlantParent Should Know”

One thing I’ve learned so far is I’m not the only young person new to gardening. The 2016 National Gardening Report found of the six million Americans new to gardening, five million of them were 18- to 34-year-olds. Millennials, according to a widely shared Washington Post article last year, are gardening indoors because they’ve moved to small, urban apartments and crave nature. Look no further than Instagram to see the evidence: hashtags like #urbanjungle and #jungalow call up all sorts of gauzy photos of apartments brimming with foliage.

What’s more: These plant parents seem genuinely proud to show off their blossoming, plant-baby families. How do they do it, I wonder? Where is a recovering plant-ignoramus to start?

I went to Fred Spicer for advice. As executive vice president and director of the Garden, he understands plants. Plus, he wears a gardening hat 80 percent of the time, so I figure he must know something.

Fred Spicer, executive vice president and director of the Chicago Botanic Garden — Fred Spicer, plant guru

Turns out “plant blindness”—or the inability to notice, appreciate, and understand plants—is a common problem among humans. The term was coined in 1998 by botanist-educators James Wandersee and Elizabeth Schussler, who argued humans generally connect more with animals, despite the fact that plants fuel all life on earth. Think back to grade school science class, when you first learned about photosynthesis and plant biology. Have you thought much about it since? I began to worry about the imbalance of affection toward my cat versus my definitely dead lemon cypress.

“Humans generally don’t think too much about plants, unless we’re eating them,” said Spicer. “We’re animals, our pets are animals, we generally know what animals want. Plants are different. They don’t have the same biology we do. So they’re mysterious to us.”

For instance, plants aren’t active, at least not in the way animals are active. Their activity happens on a different timeline than ours. Humans pay attention to big and rapid changes, like when the leaves change during the fall, or when trees are bare in winter. But the small things, like a budding leaf, we don’t always stop to notice.

OK, so plants aren’t animals. How, then, do I begin to understand them?

Here’s what Spicer recommends:

Three things every new #PlantParent should ask:

Light — No houseplant lives in the dark. Spicer asks whether your living space is plant hospitable: Do you have natural light? Are there places in your home that get more direct/indirect light? If not, are you open to artificial lighting, like grow lamps?
Maintenance — How much do you want to interact with your plants? “Do you want to fuss with them every day? Do you want to be able to leave them for a week? Some plants need more attention than others,” said Spicer. Be realistic about how much time and energy you can spend.
Purpose — What do you want to get out of your plants? Spicer asks: “Do you want to eat them? Do you want to see flowers? Do you want to create a particular design aesthetic?” Knowing your goals can help you pick the right plants.

As I sit with these questions, I think about a plant I picked up from the Garden last week. It was an azalea, a small shrub with white flowers that look like snowflakes. Left over from a recent exhibition, it most likely would die within a week, but nevertheless, as I placed it in the backseat of my car to take it home, I caught myself reaching for the seat belt. I almost buckled it in. Maybe plant parenthood won’t be so unnatural after all.

Green roofs grow up: Creating native prairies in city skylines

Pop quiz: What kind of natural habitat is increasing in urban areas? This is not a trick question. Rather, the answer offers a slice of good news on a planet that has been increasingly turning from green to gray.

Green roofs are on the rise in cities, according to Kelly Ksiazek-Mikenas, Ph.D., who has a newly minted doctorate degree from the Chicago Botanic Garden and Northwestern University’s graduate program in plant biology and conservation. In Illinois, where more than 99 percent of native prairie has been lost since the 1800s, this is especially good news.

Kelly Ksiazek-Mikenas in the Plant Science Lab — Kelly Ksiazek-Mikenas, Ph.D., in the Plant Science Lab

Dr. Ksiazek-Mikenas, a former biology teacher, spent six years studying these engineered habitats and their potential to support biodiversity.

The plant scientist is now eager to share her findings: When started carefully and with a long-term plan in mind, these sites do grow up to support species, natural communities, and genetic diversity.

“When you have these three pieces working, you have a good foundation that should sustain plant life over long periods of time and live through environmental changes, and that look and function like a diverse prairie,” she said.

Dr. Ksiazek-Mikenas examined shallow (up to six inches of soil depth), low-moisture roofs from Glencoe, Illinois, to Neubrandenburg, Germany, before reaching that conclusion. While the roofs within the United States are generally younger, some in her German sites were up to 93 years old, providing a mix of data about green roofs at all ages. She also studied data sets and conducted shorter-term experiments to clarify the qualities green roofs need to succeed.

Setting up insect traps in 2013 on a green roof on top of the Berliner Wasserbetriebe building in downtown Berlin — Dr. Ksiazek-Mikenas sets up insect traps in 2013 on a green roof in downtown Berlin.

Her work had its ups and downs. She arrived in Germany looking for similarities, expecting the insect and plant species on one roof to mirror that on the others. Rather, she found differences between roof gardens. After a deep dive into data, she found the secret. Although the plant species differed between gardens, those that grew well shared the traits of being stress-tolerant and adept at establishing themselves in new areas.

She was concerned by the lack of diversity on individual roof gardens both in Germany and in her study sites in Chicago.

Back at the Chicago Botanic Garden, she set up an experiment to test how different soil types would affect which plants were successful, and whether she could create a more diverse community on one rooftop by planting both rock and sand prairies.

She planted her experimental plots on the Josephine P. & John J. Louis Foundation Green Roof Garden North on the Daniel F. and Ada L. Rice Plant Conservation Science Center and monitored activity over three years. She found success in growing a more diverse habitat. In related work at the same site, she confirmed that native plantings, rather than the common sedum plant mix used on roof tops, offered benefits similar to a native prairie when it comes to storing rainwater, for example.

The Plant Science Center’s Green Roof Garden is an important resource. Planted in 2009, it serves as a living laboratory, classroom, research site, and a source of inspiration to visitors.

A blooming population of Penstemon hirsutus was part of Dr. Ksiazek-Mikenas’ experiments.

She then expanded to include plots on the Ellis Goodman Family Foundation Green Roof Garden South to study genetic diversity. She compared the genetic diversity of populations established from nursery stock to natural populations, finding more diversity in the natural populations grown from wild collected seed.

On the heels of that finding, she studied populations on green roofs in Chicago near Lake Michigan to find out if the plants were able to share their genetic material with plants on neighboring roofs through pollination. She was thrilled to confirm that they did, as the exchange of diverse genetic material is essential for the long-term health of a species.

Although there are limitations to green roof gardens, mainly due to the lack of soil depth and disconnected setting, Dr. Ksiazek-Mikenas is optimistic about their ability to sustain native species. She has presented her work at numerous conferences across the globe to academics and those in the landscaping industry.

Two prairie species in Dr. Ksiazek-Mikenas' experimental plots blooming on a green roof on the Peggy Notebaert Nature Museum in Chicago — Two prairie species in Dr. Ksiazek-Mikenas’ experimental plots—*Ratibida pinnata* (foreground, right) and *Lespedeza capitata* (background, left)—bloom on a green roof on the Peggy Notebaert Nature Museum in Chicago.

“In the future, I hope that green roofs can continue to provide ecosystem services to people but also increasingly support a wide variety of urban biodiversity,” she said.

The motivated researcher is ready to move ahead with her career and intends to continue to bring her unique perspective to future students and to the development of more green infrastructure in this growing world.

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’

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

Food for Thought—and for Birds

To feed, or not to feed, that is the question:
Whether ’tis nobler in the mind to suffer
The slings and arrows of empty bird feeders,
Or to take arms against a sea of winter cold
And by opposing it, feed them.

I hope William Shakespeare doesn’t mind me modifying his famous lines a little, but you get the idea. When winter arrives, we see the birds all fluffed-up out in the cold and wind and snow and feel the need to “save them,” or at least make their lives easier. For the most part, birds are perfectly capable of dealing with the weather and finding food. Most of the birds that are not able to cope have long since migrated south for the winter. Therefore, we mainly feed birds for our own benefit. It provides an opportunity to view birds up close, watch their behavior, and have a sense of doing our part for nature.

Common redpoll (Acanthis flammea) — Common redpoll *(Acanthis flammea)*

There are positive and negative things about feeding birds.

On the negative side, there is the way feeders concentrate many birds in a small area, making it easier for diseases to spread among the population. The concentration also might make them more susceptible to predation. Drawing birds closer to your home can make them susceptible to window collisions. Feeding birds can also attract unwanted animals like rats, pigeons, English sparrows, European starlings, raccoons, and house cats allowed to run outdoors.

Yellow-rumped warbler (Setophaga coronata) — Yellow-rumped warbler *(Setophaga coronata)*

On the positive side, some studies have shown that access to feeding stations increases winter populations of some species. More chickadees may survive a severe winter if food is provided than if they are totally on their own. (There is the question of whether it is truly a benefit to the population to have more individuals survive if some of those individuals are weak, genetically compromised, or carrying disease, but that is another matter.)

I think the greatest benefit to feeding birds is the connection it provides between people and nature.

In a society when people have become much more distanced from nature, feeding birds is perhaps the simplest and easiest way to make that connection. This important link to nature far outweighs any negative impacts of bird feeding. For instance, one additional benefit is the opportunity to get involved in citizen science projects. The Cornell Lab of Ornithology in New York has a Feeder Watch Program that allows members of the public to collect important population data on birds visiting their yards. It is also possible to reduce negative impacts by following a few general rules.

Pine siskin (Spinus pinus) — Pine siskin *(Spinus pinus)*

Generally, feeding birds above ground in some type of feeder is better than placing food on the ground. This will limit the number of mammals that are attracted to the feeding station. The type of feeder can limit the size and types of birds you want to feed. Tubular feeders with small (or no) perches tend to prevent large birds from accessing the food. Tubular thistle feeders have very small holes designed to provide access to the small thistle seed, limiting use to species like goldfinches, siskins, and redpolls. Applying any of a number of guards to the pole or line that supports the feeder can prevent mammals like squirrels and raccoons from getting to the feeder. If you do want to place food on the ground for ground-feeding birds like juncos and tree sparrows, place only small quantities of seed on the ground so it gets used up before the end of the day.

Robins (Turdus americanus) warming themselves on sun-heated pavement. — Robins (Turdus americanus) warm themselves on sun-heated pavement.

It is also important to think about cover for the birds. It is better to place a feeder where birds have access to some type of cover, like shrubs or evergreens. This gives them an escape route if predators—like hawks—show up. Trees and shrubs can also moderate climatic conditions around the feeder.

Keeping feeders reasonably clean is also important when it comes to reducing any disease problems that might occurs as you draw more birds to your yard. This is particularly important for tubular feeders, where birds are in much closer contact with the feeder. Washing with a weak bleach solution periodically is recommended.

What kind of food should you provide to the birds? Almost every study I have ever seen has found that the small black-oil sunflower seed is the seed preferred by the greatest variety of birds. When a seed is preferred by more species, there is less seed that gets wasted or scattered on the ground to attract unwanted birds and mammals. Although woodpeckers will also use the small sunflower seeds, they much prefer suet feeders. When shopping for suet, try to find brands that are primarily animal fat with few other ingredients like corn, millet, or milo seed.

American goldfinches (Spinus tristis) in winter plumage — American goldfinches *(Spinus tristis)* in winter plumage

Slate-colored dark-eyed junco (Junco hyemalis) — Slate-colored dark-eyed junco *(Junco hyemalis)*

Some ingredients that are beneficial are peanut pieces, hulled sunflower seed, and pieces of fruit. Generally, suet feeders do not have perches, so this limits the birds that can access the food. (One exception is the European starling that can be a problem on suet feeders. I have found that placing suet on the underside of a board allows access to woodpeckers and nuthatches, but makes it much more difficult for starlings to hang on.) Another benefit of suet is that it provides food for migrating birds that may have remained behind for various reasons. We have a yellow-rumped warbler visiting our suet feeder on a daily basis. Thistle seed is especially attractive to a variety of winter finch species. Because of its small size, it generally requires using specially designed feeders that cater to small finch species. In most cases, the cheaper brands of mixed seed often contain unpreferred seeds that serve as fillers in the mixes. It is better to avoid these, as they can produce increased waste grain that can attract unwanted guests.

Water is another good thing to provide for birds in winter. Obviously, most water sources are frozen, so it is necessary to use a bird bath heater to keep water open and available in the cold. Another nice thing about water is that it will attract birds that might not normally visit a feeding station, especially as temperatures warm up. Some people who have kept a species list for birds visiting their yards have found that their list more than doubles once water is provided.

Northern cardinal (Cardinalis cardinalis) — Northern cardinal *(Cardinalis cardinalis)*

One last point to keep in mind is that the appearance of birds at your feeder can change due to fluctuating weather patterns. If we experience a period of mild weather, the birds may be off finding naturally available food and not find it necessary to come to you feeder. You may experience a week or more when almost no birds show up at your feeder. This is a normal occurrence and should not be considered an indication of some environmental problem affecting the health of the local bird population.

So if you have a desire to get more involved with the birds in your yard, follow these few simple guidelines and let the enjoyment begin.

Come #birdthepreserves with the FPDCC; view the list of upcoming events for free events near you.