native plants – My Chicago Botanic Garden

Getting That Tropical Look

This season’s Brazil in the Garden exhibition features a bold tropical look at the Chicago Botanic Garden—you can get that same vibrant feel in your home garden, using perennial plants.

Surprisingly, there are a number of plants that thrive in the Chicago area in spite of their tropical looks. With attributes ranging from huge leaves, delicious fruits, or potent fragrances, these trees and shrubs will add a tropical splash to your backyard year after year.

Magnolia ashei is one of the most tropical-looking plants at the Chicago Botanic Garden. It features huge leaves, huge flowers, and huge fruits. The leaves can grow up to 36 inches long, the flowers can be more than a foot across, and the fruits are up to 5 inches long and turn bright red. Magnolia ashei has an irregular growth habit and makes a bold specimen. Look for this one in the Native Plant Garden (however, this plant is not an Illinois native).

PHOTO: Magnolia ashei — *Magnolia ashei* has beautiful leaves and intriguing fruit.

Another large leaf magolia, Magnolia tripetala x obovata, is similar in most respects; however, it features a broad, round form and is a bit more formal in the landscape. This magnolia can be found in the Waterfall Garden.

Campsis radicans is a native vine with large, orange-red, trumpet-shaped flowers all summer long. The flowers are a hummingbird magnet, which just adds to the tropical allure, and are available in numerous colors, including red, orange, and yellow. This is a large, growing vine so give it room to grow. It does tolerate pruning but blooms best when allowed to grow uninterrupted. Even the seed pods are ornamental, looking almost like green bananas hanging from the flower clusters. Look for it in the Waterfall Garden, and the fence surrounding the Graham Bulb Garden, where we have red and yellow varieties mixed together.

PHOTO: Campsis radicans — *Campsis radicans* grows in the Waterfall Garden.

PHOTO: Asimina triloba — Pawpaw (*Asimina triloba*) fruits hang high in the tree.

Another native plant that wouldn’t look out of place in the rain forest is the pawpaw tree (Asimina triloba). This native tree has green leaves that can reach a foot long. It’s a beautiful understory tree that will grow well in dappled shade with ample moisture (but never standing water). However, the real reward with pawpaws are the fruit. These large fruits have an incredibly tropical flavor, like a mix of mango, pineapple, and bananas. The fruit are among the last to ripen in the late summer and well worth the wait. To get a good crop of fruit, make sure to plant two varieties.

Pawpaws also get beautiful golden fall color, which only adds to their appeal. One note of caution however: the trees can sucker, so make sure to plant your pawpaw somewhere where this isn’t a problem, or make sure to remove the suckers as they sprout. Look for pawpaws in the Bulb Garden, Regenstein Fruit & Vegetable Garden, and Native Plant Garden.

And finally, what is a tropical garden without lush fragrances? Clethra alnifolia is a hardy shrub that thrives in partial shade and boasts intensely fragrant blooms in late summer.

PHOTO: Clethra alnifolia 'Rosea' — *Clethra alnifolia* ‘Rosea’ has cheerful pink flowers that hummingbirds love.

PHOTO: Clethra alnifolia 'September Beauty' — *Clethra alnifolia* ‘September Beauty’ is one of the latest-blooming summer-sweet cultivars.

Clethra flowers have a rich smell similar to gardenia, but with spicy undertones. The flowers are tall spikes of white or pink and are a magnet for pollinators such as honeybees and hummingbirds. With careful planning, you can mix varieties of clethra and have blooms that last from mid-July through late August. Several varieties of clethra can be found in the Sensory Garden.

See Brazil in the Garden through October 15, 2017.

Water Works

In a first-time summer internship research project, two college students set out to understand how plants were responding to the Garden’s shoreline restoration projects. They took a deep look into how variations in water levels may be affecting the health of the young plants. The results of their work will help others select the best plants for their own shorelines.

A silent troop of more than one-half million native plants stand watch alongside 4½ miles of restored Chicago Botanic Garden lakeshore. The tightly knit group of 242 taxa inhibit erosion along the shoreline, provide habitat for aquatic plants and animals, and create a tranquil aesthetic for 60 acres of lakes.

PHOTO: The North Lake shoreline. — The North Lake shoreline restoration was completed in 2012. Photo by Bob Kirschner

Now ranging from 2 to 15 years old, the plants grow up from tiered shelves on the sloping shores. Species lowest on the slope are always standing in water. At the top of the slope, the opposite is true, with only floods or intense downpours bringing the lake level up to their elevation.

Wading In

Jannice Newson and Ben Girgenti moved through clusters of tightly knit foliage along the Garden shoreline from June through August, taking turns as map reader or measurement taker. On a tranquil summer day, one would step gingerly into the water, settling on a planting shelf, before lowering a 2-foot ruler into the water to take a depth measurement. The other, feet on dry land, would hold fast to an architectural map of the shoreline while calling out directions or making notes.

Newson, a Research Experiences for Undergraduates (REU) intern and sophomore at the University of Missouri, and Girgenti, a Garden intern and senior at Brown University, worked under the guidance of Bob Kirschner, the Garden’s director of restoration ecology and Woman’s Board curator of aquatics.

PHOTO: Interns Ben Girgenti and Jannice Newson. — Interns Ben Girgenti and Jannice Newson gather plant data on the shoreline.

When the summer began, Girgenti and Newson had hoped to locate and measure every single plant. But after the immense scope of the project became clear in their first weeks, they decided to focus on species that are most commonly used in shoreline rehabilitation, as that information would be most useful for others.

View the Garden’s current list of recommended plants for shoreline restoration.

“We’re interested in which plants do really badly and which do really well when they are experiencing different levels of flooding, with the overall idea of informing people who are designing detention basins,” explained Girgenti, who went on to say that data analysis of the Garden’s sophisticated shoreline development would be especially useful for others.

“The final utility of this research will be to inform other natural resource managers,” confirmed Kirschner, who added that successful Garden shoreline plants must be able to withstand water levels that can rise and fall by as many as 5 feet several times in one year.

Steering the Ship

Along the shoreline, the interns followed vertical iron posts that were installed as field markers during construction, in order to find specific plants shown on the maps. “The posts are pretty key to being able to map out the beds,” said Girgenti.

PHOTO: The Malott Japanese Garden shoreline 3 years after the 2011-12 restoration project. — The Malott Japanese Garden shoreline two years after the 2006 restoration project.

Once they found a target plant, they then counted clumps of it, and put it into one of six categories based on the amount of current coverage, ranging from nonexistent to area coverage of more than 95 percent.

They also measured the average depth of water for beds with plants below the water line, noting their elevation. For plants above the water line, the elevation was derived from the architectural drawings.

Data about the elevation and coverage level of each measured plant, together with daily lake water level readings dating back to the late 1990s, was then entered into a spreadsheet and prepared for analysis to identify correlations between planting bed elevation and plant survival.

Beneath the Surface

For her REU research project, Newson was careful to collect data for one species in particular, blue flag iris. “As a preliminary test of the project hypothesis, data relating to 101 planting beds of Iris virginica var. shrevei were analyzed to see if there was a significant correlation between the assessed plant condition and each planting bed’s elevation relative to normal water,” she explained in her final REU poster presentation in late August.

PHOTO: Southern blue flag iris. — Southern blue flag iris (*Iris virginica* var. *shrevei*), photo by Jannice Newson

An environmental science major, she initially experienced science at the Garden as a participant in the Science First Program, and then as a Science First assistant, before becoming an REU intern.

Girgenti began his Garden work in the soil lab, where his mentor inspired him to focus on local, native flora. “I was kind of pushed up a little bit by the Garden,” he said. The following year he did more field work in the Aquatics department. “I wanted to come back because I really enjoyed being here the last two years,” he said. “Every year I’ve come back to the Garden, I’ve been very excited about what I’m going to do.”

Aside from the scientific discovery, the two also refined their professional interests. “I do enjoy being out in the field as opposed to maybe working in a lab; it’s a lot more interesting to me. And also just working in the water with native plants is very interesting,” said Newson.

“I was really interested in getting into more of the shoreline science and also learning which native species were planted there,” said Girgenti. “I really love working here. I’ve never really been involved this much in science, so this has been a really great experience—just all of the problem solving that we’ve had to do over the course of the summer.”

Newson also enjoyed the communication aspect of her work, as Garden visitors stopped to ask what work she and Girgenti were doing along the shoreline. She was especially excited to share with them and her fellow REU interns that “the purpose of why we are doing this is that it provides a beautiful site for visitors to see, it helps with erosion, and also improves aquatic habitat.”

PHOTO: View of the Kleinman Familly Cove. — A view of the Kleinman Family Cove highlights the small bay where our youngest science explorers can learn about the shoreline.

Although the interns have left the Garden for now, the data they collected will have a lasting impact here and potentially elsewhere. Kirschner is currently working with his colleagues on the data analysis to complete a comprehensive set of recommendations for future use.

Mud puddling…

Imagine this:

PHOTO: Monarch butterfly on scarlet bloodflower. — A monarch butterfly enjoys the nectar of plants in the milkweed family (*Asclepias* species).

You are a monarch butterfly. You weigh less than one gram. You are traveling 1,000…2,000…perhaps 3,000 miles on migration from Mexico to your northern breeding grounds. You are desperate for flower nectar; for the safety and shelter of shrubs and trees; for shallow, still water to “mud puddle” in; and for milkweed plants on which to lay your eggs. Suddenly you see a sea of color—a flower-filled yard in a yawn of lawns…

You are a hummingbird. You weigh less than a pencil. You have just flown 500 miles nonstop (not to mention crossing the Gulf of Mexico) in search of the perfect spot to build your walnut-sized nest. You need fuel: the nectar from tube-shaped flowers, and lots of it, as in sips from 1,000 flowers per day. Suddenly you see a mass of flowers below…

PHOTO: Hummingbird hovers for nectar from a pink turtlehead bloom. — Pink turtlehead (*Chelone glabra*) is a late-summer favorite of hummingbirds.

You are a homeowner with a yard. You are weighing a new approach to your landscape: you’d like to incorporate butterfly/hummingbird-friendly plants. You’ve heard about butterfly bushes, and you picture a yard filled with flitting and fluttering all summer long.

You need Tim Pollak. He’s the outdoor floriculturist at the Chicago Botanic Garden, and he’s our resident butterfly guy, who teaches frequent classes at the Joseph Regenstein, Jr. School of the Chicago Botanic Garden on the subject of attracting butterflies and hummers to your yard. Consider this a mini-class: in the video below, Tim brings you up close to flowering plants that are both butterfly-attractive and visually attractive to you and your neighbors.

Click here for Tim’s tip sheet of simple steps for attracting all sorts of winged creatures to your yard.

Imagine that!

Spring Woodland Wildflower Walk

What’s a spring ephemeral? Ecologist Jim Steffen tells us about a few of the spring blooming wildflowers you can see blooming in McDonald Woods right now. As Jim says, there is always something in bloom in the woods, but spring is one of the showiest in this area, so don’t miss it! Visit http://www.chicagobotanic.org/walk/mcdonald_woods.php for more information on the woods.

How To Make A Bee Condo

Native bees are critically important in pollinating our plants. This video provides easy-to-follow instructions on how to build a home for bees in your garden so they can continue to pollinate your plants all season long. This is just one of the many environmentally-friendly gardening practices that you can learn during World Environment Day at the Garden on Saturday, June 4, 2011. Visit www.chicagobotanic.org/wed2011 for more information.