Archives For August 2017

Last month, torrential rains fell over much of our region, particularly in Lake and McHenry counties, as well as southeastern Wisconsin. Here at the Chicago Botanic Garden, high water levels in the Skokie River forced us to close on July 13 and 14—the first time in the Garden’s history that we’ve been closed to visitors for two consecutive days. 

So what exactly happened that required us to close? And how did the flooding affect our plants? 

Flooding at the visitor entrance’s main intersection

Flooding at the visitor entrance’s main intersection

Skokie River watershed map

The Skokie River watershed, highlighted in blue. (Click here for larger view.)

The Garden is situated in the “watershed” of the Skokie River that extends north to Waukegan. A portion of the rain that falls in this upstream, 20-square-mile watershed eventually finds its way to the Skokie River. During the early morning of July 12, between 3 and 5 inches of rain fell in that watershed area over a matter of hours, resulting in a rapid rise in the Skokie River as it flows around the west side of the Garden. In fact, the rainfall was so severe that portions of the village of Lake Bluff (located in our watershed) experienced rainfall intensity and quantity that is predicted to occur with a frequency of only about once every 140 years.

Prior to the Garden’s creation, the Skokie River meandered through the middle of our property. As the Garden began to take shape in the late 1960s, heavy construction equipment excavated our lakes (some exceed 16 feet deep), and those soils were then used to create the islands and display gardens that you enjoy today.

At the same time, the Skokie River was moved into a defined channel on the west side of our property near the highway, and two dams were installed at the north and south ends of our lake system to isolate it from the river except during high flows (see graphic). These dams were installed to help protect communities downstream of the Garden from flooding: if levels in the Skokie River rise high enough, river water flows over the north dam into the Garden lakes and we’ll temporarily store over 100 million gallons of floodwater. After the river’s flood peak has passed, we slowly release that water out of the Garden’s lakes and back into the Skokie River.

Map of the lakes and dams in the Chicago Botanic Garden.

Map of the lakes and dams in the Chicago Botanic Garden. (Click here for a larger view.)

Last month’s flooding at the Garden was dramatic. Our lake levels rose more than 5.5 feet above normal and were on par with the highest we’ve ever encountered. At one point early in the flood, an intersection along the Garden’s visitor entrance was submerged under more than 30 inches of water—thereby necessitating our closure.

The image below shows one of our service roads during normal water levels as it crosses a narrow point in our lake system. Compare that image to the video, taken at the peak of the floodwater inflow to the Garden, showing swift and powerful water flowing through this area. 

About three days after the heavy rains fell, the flood peak had passed, and the Garden was able to begin releasing lake water back into the Skokie River via a 10,000 gallon-per-minute pump near the south dam. Nine days later, all 100 million gallons of floodwater had been removed and our lake levels were back to normal.

The Rose Garden causeway August 16, 2017

One of the Garden’s service roads on August 16, 2017; and below, on July 13, 2017

The images below illustrate the extent of the high water levels at the Garden. Remember, at their peak, the lake levels were more than 5.5 feet above normal.

The Serpentine Bridge on July 13, 2017

The Serpentine Bridge on July 13, 2017

The Serpentine Bridge on August 22, 2017

The Serpentine Bridge on August 22, 2017

The lower walkway pergola in the Bulb Garden on July 13, 2017

The lower walkway pergola in the Graham Bulb Garden on July 13, 2017

The lower walkway pergola in the Bulb Garden on August 16, 2017

The lower walkway pergola in the Bulb Garden on August 16, 2017

Because the Garden was intentionally designed from the very beginning to accept and temporarily store floodwater from the Skokie River, we’ve experienced few long-term impacts from the recent flood. None of our buildings took on any water. Most of the vegetation near the lakeshore that went underwater survived. There was some damage to plants in the Garden—a few inundation-sensitive shrubs and herbaceous plants, as well as some turf were affected (particularly along the water’s edge of the Malott Japanese Garden). Some were pruned and others may need to be replaced with more water-tolerant taxa. Importantly, more than 500,000 native shoreline plants that we’ve installed along the Garden’s lakeshore withstood being underwater for up to nine days without impact. These plants will continue their important “engineering function” to stabilize our fragile shoreline soils and keep the slopes from eroding into the lake.

The recent heavy rainfall and flooding were of historic proportions and caused devastation to many communities in our region. Looking forward, residents can take steps to help lessen flooding: for example, installing a rain garden on your property can help reduce flooding, particularly for small- and modest-sized storm events; click here for more information. Regional solutions for stormwater management can be particularly beneficial for larger rainfall events. Countywide stormwater management agencies in our region work to implement flood control programs and help homeowners who have been affected by flooding. For more information about these agencies and the programs they offer, in Cook County, contact the Metropolitan Water Reclamation District; in Lake County, contact the Lake County Stormwater Management Commission.

And so while the recent flooding may have left a bit of soil residue on some leaves of plants located nearest the lakeshore, rest assured that all is quite well here at the Garden. In fact, the frequent rains this summer have contributed to luxuriant growth and some amazing blooms, and we look forward to a continued explosion of color as summer progresses into fall.


©2017 Chicago Botanic Garden and my.chicagobotanic.org

Sunshine is the latest corpse flower at the Chicago Botanic Garden to bloom.

A member of the Aroid plant family (Araceae) from Sumatra, it has a number of titan arum relatives at the Garden from around the world.

Sunshine the titan arum (Amorphophallus titanum) in the Sensory Garden

Sunshine the titan arum (Amorphophallus titanum) in the Sensory Garden

Jack-in-the-Pulpit (Arisaema triphyllum) and Skunk Cabbage (Symplocarpus foetidus) are the two most common Chicago natives in this family. Other relatives hail from continents, regions, countries, and islands. Taxa growing at the Garden have the following native ranges: North America, Northeastern United States and Canada, Japan, Korea, China, Thailand, Russian Far East, Kamchatka Island, Sakalin Island, the Philippines, Indonesia, Sumatra, Sri Lanka, Turkey, Greece, Republic of Georgia, Spain, Italy, India, Nepal, Afghanistan, Tibet, Burma, Himalayan Mountains, Yemen, Mexico, Central America, Panama, Guatemala, Caribbean Islands, South America, Colombia, Peru, South Africa, and Lesotho.

Jack-in-the-pulpit (Arisaema triphyllum)

Jack-in-the-pulpit (Arisaema triphyllum)

Skunk cabbage (Symplocarpus foetidus)

Skunk cabbage (Symplocarpus foetidus)
Photo by Jacob Burns

Not only is it widespread, the members are also adapted to a number of environments from hot, humid Sumatra rain forests where Sunshine calls home to cold, temperate deciduous forests, temperate and tropical wetlands, Mediterranean climates, and deserts.

Find caladiums and others as you stroll Brazil in the Garden this summer; visit #CBGSunshine the titan arum outside in the Sensory Garden and stay tuned for a potential bloom!

The Araceae is one of the larger plant families, containing 117 different genera. The Garden features 27 of those genera containing 152 species and cultivars. Our GardenGuide smartphone app features the locations where Sunshine’s family can be seen throughout the Garden. Many are grown ornamentally for their attractive leaf shape (philodendrons, anthuriums) and colorations (elephant ears, caladiums, dieffenbachia, pothos, taro) while others, anthuriums and Calla lilies chief among them, are grown for their attractive flowers. While not all members of the family smell bad—the Calla lily, for instance, has a light citrus fragrance and anthuriums don’t have any fragrance at all—many are real stinkers with common names like Dead Horse Arum, Dead Mouse Arum, and Corpse Flower.

Caladium bicolor 'White Dynasty'

White Dynasty caladium (Caladium bicolor) ‘White Dynasty’

Calla lily (Zantedeschia aetiopica)

Calla lily (Zantedeschia aetiopica)

Caladium 'Red Flash'

Red Flash elephant ear (Caladium ‘Red Flash’)

Most members of the family contain a number of compounds (often including calcium oxylate crystals) in their sap to deter herbivores that illicit a mechanical gag reflex in people. Calcium oxylate crystals look like glass shards on steroids under a microscope and play havoc with the soft tissues of the inside of the mouth, tongue, and throat. The most notable food crop in this family? Taro, or poi. Preparation of the starchy tubers have adapted techniques over the centuries that remove the toxic compounds.

Ready for an Aroid treasure hunt?

Find these titan arum relatives as you stroll the Tropical Greenhouse, where a titan arum leaf is also housed. Can you spot the family resemblance? 

Anthurium andraeanum 'White Heart'

Flamingo flower (Anthurium andraeanum ‘White Heart’) is a classic anthurium flower of the florist trade in white with a red spadix; find it near the east entrance.

Anthurium x garfieldii

Find Garfield anthurium (Anthurium × garfieldii) in classical birds’ nest form with a long, thin flowering spathe and a spadix in dark maroon. Photo by horticulturist Wade Wheatley.

Monstera deliciosa

Split leaf philodendron or Swiss cheese plant (Monstera deliciosa) has a vining habit; it is clambering up the side of the greenhouse sporting large, deeply divided leaves.

Dieffenbachia 'Camouflage'

Its name says it all: Camouflage dumb cane (Dieffenbachia ‘Camouflage’) is hidden west of the palm alleé.

Amorphophallus titanum leaves in the Production Greenhouses

Amorphophallus titanum leaves in the production greenhouses. Find one in the Tropical Greenhouse, too.


©2017 Chicago Botanic Garden and my.chicagobotanic.org

A gall, tumor, or burl is an abnormal growth on the leaves, stems, roots, buds, twigs, or crown of a plant. In most cases, the gall is unsightly but not damaging. In small plants, the vascular flow of water and food can be restricted, causing poor growth and making the plant more susceptible to other stresses. A large tree can be weakened by an infection over many years. Nematodes, mites, and insects cause 95 percent of galls. Bacteria and fungi cause the remaining five percent. In most cases, the gall-making organism can be identified by observing the structure of the gall and the species of the host plant.

Galls on a Flower

Galls on Rudbeckia laciniata ‘Herbstsonne’

Fungal galls are spread by ascospores in wind and water and can be found on many common trees including oak, maple, and common privet. Black knot affects many species of the genus Prunus—particularly cherries and plums.

Crown gall is a common problem caused by bacteria. The disease is spread by infested soil, transplants, or contaminated tools. The bacteria enters the plant through wounds caused by cultivation, pruning, or insects. Easy prevention methods are to plant only healthy stock (no suspicious bumps), to clean pruners between use on each plant with alcohol or a 10 percent bleach/water solution, and to take care not to injure plant stems. The bacteria stays active in the soil even after removal of infected plants, so place new, healthy stock elsewhere. Remove and destroy all infected plants. Galls caused by bacterial and fungus are more prevalent during wet years.

A gall can form in response to toxins injected during insect feeding or egg laying, or around a feeding larva. The hackberry leaf gall is caused by psyllids, which are tiny winged insects. Galls formed by insects usually do not affect the overall health of the tree unless they experience early defoliation over the course of many years. Parasites are an important control of this pest. Many oak galls are caused by gall flies and generally are not detrimental. A severe twig infection can, however, cause severe injury and even death. Spruce galls are often caused by several species of an aphid-like insect. If only a few galls are present, they can be cut off and destroyed before the insects emerge in midsummer.

Galls on a Flower
Galls on a Flower

 

Leaf galls on maple trees form because of feeding mites. Eriophyid mites produce a gall that resembles a felt patch and may occur on the upper or lower side of the leaf. The overall health of the tree should not be seriously affected.

Nematode feeding activity can injure roots and allow gall-forming bacteria into the plant. Nematodes can also form galls on carrots, camellia, fig, gardenia, okra, potato, roses, sweet potato, and tomato. Plants can be stunted, yellow, and wilted due to restrictions on the uptake of water and nutrients. Individual nematodes are invisible to the naked eye, but egg masses can be seen as pearly objects.  Roots can appear scabby, pimpled, rough, and have knots. Two important prevention methods are to rotate with nematode-resistant crops and to maintain rich organic soil.

Please contact Plant Information Service at (847) 835-0972 or at plantinfo@chicagobotanic.org for additional information.


©2017 Chicago Botanic Garden and my.chicagobotanic.org

We love nature here at the Chicago Botanic Garden, so we looked to the natural world for inspiration on how to enjoy the eclipse—here at the Garden, or in your own backyard.

Practice safe viewing at the Garden with eclipse glasses from the Adler Planetarium.

Practice safe viewing at the Garden with eclipse glasses from the Adler Planetarium. Distribution of glasses begins at 10 a.m. Monday, August 21 on the Esplanade.

On Monday, August 21, people across the United States will be able to witness a rare event: the first total solar eclipse to cross over the country from coast to coast in nearly a century.

The path of totality—meaning the area of the United States that will see the sun completely blocked by the moon—passes across southern Illinois. In the Chicago area, we will experience roughly 86 percent coverage around 1:19 p.m. This is the closest the Chicago area has been to a total solar eclipse in 92 years.

 

1. Make a pinhole projector—using leaves.

Rule number one with eclipses—and with the sun every day, actually—is don’t look directly at it with the naked eye. A fun way to indirectly “see” the eclipse is with a pinhole projector, and one of the best natural projectors is a leaf. Leaves often have holes that can act as natural projectors.

During the eclipse, turn your back to the sun and hold the leaf above a neutral colored background, ideally several feet or more away. A white sheet of paper will do. You’ll see a crescent-shaped shadow that changes as the eclipse progresses.

Via Rice Space Institute, a fun way to commemorate an eclipse: make a pinhole sign and photograph its shadow.

Via Rice Space Institute, a fun way to commemorate an eclipse: make a pinhole sign and photograph its shadow.

The easiest pinhole projector you can make is with your hands. Stretch out and overlap your fingers to create a grid. Look down and you’ll see mini eclipses projected through the spaces between your fingers.

Eclipse shadows seen through crossed fingers of kids.

Viewing with children? Use what you’ve got to make your own shadow art: tiny hands are perfect. Photo via blogger Linda Shore

Other ideas: Use everyday objects that already have holes—like colanders or crackers, for example—or by punching a hole in a piece of cardboard or other sturdy material. If you want a more patriotic experience, NASA has 2D/3D printable pinhole projectors in the shape of the United States and each state.


2. Follow the shadows of the trees.

Find a shady spot and watch as the eclipse shadows change over the course of the event. Instead of the one shadow that a standard pinhole projector creates, you can view hundreds by standing under a decently sized oak or maple.

Instead of the shadows of leaves, thousands of sun crescents: the light cast through the gaps in moving leaves is only a sliver of the sun, and it shows.

Instead of the shadows of leaves, thousands of sun crescents: the light cast through the gaps in moving leaves is only a sliver of the sun, and it shows. Photo by David Prasad from Fresno, CA., United States [CC BY-SA 2.0], via Wikimedia Commons, taken during the 2012 annular solar eclipse seen on the west coast of the United States.

Shadows of leaves on the ground during a partial solar eclipse look like a host of small, overlapping crescent moons.

Shadows of leaves on the ground during a partial solar eclipse look like a host of small, overlapping crescent moons. Photo by பரிதிமதி (Own work) [CC BY-SA 3.0], via Wikimedia Commons

Another cool effect created by the eclipse is shadows that look sharper and appear to move (albeit very slowly) as the eclipse goes on. Boyce Tankersley, the Garden’s director of living plant documentation, was in St. Louis during the annular solar eclipse that passed over the United States in 1994, and witnessed this phenomenon while working at the botanical garden there. Unlike the annular 1994 eclipse, where a ring of the sun appears around the edge of the moon, the total eclipse this year will completely block the sun’s light in the path of totality (near Carbondale, Illinois, in our region). That’s because during a total eclipse, the distances between the moon, sun, and earth allows the moon to completely cover the sun; during an annular eclipse, it does not.

Rangers in Grand Canyon National Park use eclipse filters on a pair of binoculars during an annular eclipse viewing in 2012.

Rangers in Grand Canyon National Park use pair of filtered binoculars during an annular eclipse viewing in 2012. Note the crisp shadows at near-peak eclipse, as well as the crisp outline of the crescent sun.
[CC BY 2.0], via Wikimedia Commons

At peak viewing time, from roughly 12:45 to 2 p.m., we’ll see a skinny crescent of light peeking out from behind the moon, almost like it’s taking a bite out of the sun. Though it’s only a sliver, it’s still strong enough to mess with the way shadows appear to the naked eye. This will make for some amazing patterns and changing shapes under the Garden’s trees. If you want to experience the eclipse this way, Tankersley recommends heading to the Waterfall Garden, English Oak Meadow, or English Walled Garden. Even the Garden’s parking lots have big, leafy trees that would work. If you prefer seclusion, the west service road, stretching from the Regenstein Learning Campus to the Graham Bulb Garden, has ginkgo, redbud, and buckeye, to name a few trees in that area with interesting leaves. Use the Garden’s plant finder or download our GardenGuide app to seek out a spot to see the eclipse by your favorite kind of tree.


3. Come to the Garden’s Eclipse Event

The Garden has partnered with the Adler Planetarium to host a solar eclipse viewing event. Free special viewing glasses—while supplies last—will be available so visitors can safely view the eclipse directly. We’ll also have Family Drop-In activities related to the eclipse and a scale model of the moon, sun, and earth stretching across the Esplanade, not far from the Visitor Center.

Crescent-shaped shadows of an eclipse seen through a colander.

Colanders, strainers, slotted spoons, and crackers—use household objects for your own eclipse experiments. Photo via Lightscapes blog.

The Esplanade is going to be a hub of activity, but the Garden has a number of other open spaces for great viewing. Grab your eclipse glasses and head to Dixon Prairie, on the south end of the Garden. When you need a break from staring at the sky, you’ll also see blooming blazing star, wild bergamot, prairie dock, and ironweed. If you’re lucky, you may also spot a hummingbird or monarch butterfly. The prairie is right off the section of the North Branch Trail that winds through the eastern part of the Garden, so it’s easily accessible if you bike here from the south.

Not as off the beaten path, but usually a sure bet for some private space, is Evening Island. It’s home to the Theodore C. Butz Memorial Carillon and features different landscapes on five acres. Head to the lawn overlooking the Great Basin for a clear view of the sky, as well as sweeping, photo-ready vistas. If you’re with a small group, gather in the council ring, inspired by the work of famed garden designer Jens Jensen.


If you miss this year’s total solar eclipse you won’t have to wait too long for the next one. There will be another in seven years, with the Chicago area closer to the path of totality and expected to see roughly 93 percent coverage. Practice your skills this year and you’ll be proficient in eclipse observation by 2024.


©2017 Chicago Botanic Garden and my.chicagobotanic.org

Towering palms, bold swaths of color, and tropical plants have transformed the Chicago Botanic Garden into an exotic paradise this year for Brazil in the Garden.

To create the “Brazil effect,” floriculturist Tim Pollak and Andrew Bunting, the Garden’s assistant director and director of plant collections, drew from designs by renowned Brazilian landscape architect Roberto Burle Marx, who was known for his bold, modernist style.

We talked with Pollak and Bunting to learn how you can grow a Brazil-inspired tropical garden.

Aechmea 'Blue Tango'

Aechmea ‘Blue Tango’

1. Find color in foliage

Burle Marx used bold, bright colors such as purple, orange, and green in his gardens. When planting your garden, Pollak recommended choosing foliage plants with various shades of green. Foliage tones are endless: silvers, blues, bronze, and burgundy. Foliage plants can also bring out the colors of flowers, and vice versa. For instance, if your garden’s foliage is silver, blue, and purple, pops of white flowers will enhance the foliage colors. “Remember,” Pollak said, “there are no rules when it comes to color.” Complementary or monochromatic schemes are subject to taste. But gardens can still be attractive without flowers. Instead, think of flowers as icing on the cake.

Codiaeum variegatum var. pictum 'Pie Crust'

The bright, speckled foliage of Codiaeum variegatum var. pictum ‘Pie Crust’ provides a host of contrasting color all in one plant.

2. Use contrasting textures and shapes

Burle Marx was known for using large swaths of contrasting textures and forms in his landscape designs. Get the Burle Marx effect by choosing plants with various surfaces and shapes. For instance, Pollak said to think about the foliage of your plant—is it shiny or muted? Waxy or fuzzy? Is the venation (patterns of veins on the leaf) netted or in parallel lines? Are the shapes of the leaves long and thin, or short and wide? When shopping at your local garden center or nursery, follow Pollak’s trick: Lay your plants next to each other on your cart or on the floor. You’ll see which plants have different styles, which create a lush, biodiverse mood in your garden.

Calathea burlemarmii 'Burle Marx' and Heuchera 'Dark Mystery'

This Burle Marx peacock plant (Calathea burlemarmii ‘Burle Marx’) surrounded by the dark purple leaves of Dark Mystery coral bells (Heuchera ‘Dark Mystery’)

3. Think: thrillers, fillers, and spillers

Pollak and Bunting often advise gardeners to think “thrillers, fillers, and spillers” when planning their garden design. By using a combination of these kinds of plants, you can easily create a varied garden design. Here’s a breakdown of the three types:

  • Thrillers: Tall plants are your “wow factors.” They’re dramatic, and stand out in your garden. Think of these plants as conversation starters. Pollak and Bunting recommend palms (Arecaceae), elephant ears (Colocasia), and cannas (Canna generalis) for Brazil-themed “thrillers.”
  • Fillers: Medium-sized plants fill space in your garden. They can be interesting foliage plants or flowers, or flowers with interesting foliage. Pollak and Bunting recommend Persian shield (Strobilanthes dyerianus) and firecracker plants (Cuphea ignea) for Brazil-themed “fillers.”
  • Spillers: Low plants spill out of a container, or trail along the foot of your garden bed. Pollak and Bunting recommend sweet potato plants (Ipomoea batata) and purple spiderwort (Tradescantia pallida) for Brazil-themed “spillers.”
"Thrillers," "spillers," and "fillers" in the Crescent Garden.

In the Crescent Garden, Bismarck fan palms (Bismarckia nobilis) and canna (Canna × generalis ‘Orange Punch’) create “thrillers.” The spectacular foliage of Grecian urn plant (Quesnalia marmota) and bromeliad Neoregelia ‘Sunkiss’ fill in the planting (“fillers”). Mexican bluebell (Ruellia brittoniana ‘Purple Showers’) and Purple Heart spiderwort (Tradescantia pallida ‘Purple Heart’) create the “spillers” in the grouping.

4. Create repetition for effect

When arriving at the Garden’s Visitor Center, you might imagine you’ve landed in Miami. Rows of swaying coconut palms, towers of bromeliads, and beds of elephant ears greet visitors as they walk through the Garden. The tropical illusion is deliberate: We repeated similar plants in our beds to broaden the Garden’s designs, making small spaces look larger. In your own garden, you can use swaths of similar plants in rows or curving shapes. The result may transport you to the tropics.

Repetition for effect: planting areas with a single plant create an effect of making an area seem larger.

Repetition for effect: planting areas with a single plant create an effect of making an area seem larger. Golden yellow Duranta erecta ‘Aurea’ is planted around a Buccaneer palm (Pseudophoenix sargentii). Dark Neoregelia ‘Royal Burgundy’ is planted at the front of the bed alongside a grouping of fine-textured Stipa tenuissima feather grass. Behind the palm, a grouping of spiky-leafed Naranjilla contrasts with the fuzzy-leaves of Tibouchina grandifolia.

5. Add a touch of tropics

Planting a tropical-themed garden doesn’t require you to use 100 percent tropical plants, said Bunting, but a few plants can have an impact. To create a Brazil-themed garden, do as Burle Marx did: Find plants within your reach. That is, at your local garden center or nursery, find palms or other tropical plants that can be brought inside for the winter. To care for tropical plants, keep in mind they thrive in heat and humidity, and need plenty of moisture. Use supplementary fertilizer to keep them healthy and thriving. And remember, if you want the tropical effect without tropical plants, there are plenty of ways to think creatively by using bold houseplants, annuals, and perennials.

Aechmea 'Yellow Berries'

Vase plant (Aechmea ‘Yellow Berries’) adds a perfect touch of the tropics to your summer displays.

Learn more about the flora and fauna of Brazil in our upcoming conservation talks, held on the following Thursdays from 2 to 3 p.m. in the Linnaeus Room, Regenstein Center.

AUG
10
Birds of Brazil
Doug Stotz, senior conservation ecologist, The Field Museum
AUG
17
A Butterfly Adventure in the Amazon Basin
Doug Taron, chief curator of the Chicago Academy of Sciences, Peggy Notebaert Nature Museum
SEP
28
Plant Diversity and Conservation in Brazil
Pat Herendeen, senior director, Systematics and Evolutionary Biology, Chicago Botanic Garden
OCT
12
Mycological Adventures in Brazil
Greg Mueller, chief scientist and Negaunee Foundation Vice President of Science, Chicago Botanic Garden

Photos by Tia Mitchell Photography
©2017 Chicago Botanic Garden and my.chicagobotanic.org