Archives For Education

The Chicago Botanic Garden offers classes for every age, interest, and skill level with instruction by experts in their fields.

On any given day, the Chicago Botanic Garden’s science laboratories are bustling with activity. Some of the researchers are extracting DNA from leaves, analyzing soil samples, discussing how to restore degraded dunes—and talking about where they’re going to college. The young researchers are interns in the Garden’s College First program, studying field ecology and conservation science, and working side by side with scientists, horticulturists, and educators.

PHOTO: Orange-shirted middle schoolers examine palm trees and take data in the greenhouse.

Science First participants gather data in the Greenhouse.

PHOTO: Two high school girls wearing blue "College First" tshirts and latex gloves examine samples in the lab.

Two College First participants work on analyzing samples in the Garden’s plant science labs.

The Science Career Continuum consists of five programs:

  • Science First, a four-week enrichment program for students in grades 8 through 10.
  • College First, an eight-week summer internship for high school juniors and seniors with monthly meetings during the school year.
  • Research Experiences for Undergraduates (REU), a ten-week summer research-based science internship supervised by a Garden scientist and funded through a National Science Foundation grant. In 2014, three College First graduates will participate.
  • Conservation and Land Management (CLM) internship, offered through the Department of the Interior’s Bureau of Land Management and held in 13 western states.
  • Graduate programs in plant biology and conservation, offered jointly with Northwestern University for master’s degree and doctoral students.

The program is part of the Science Career Continuum, which is aimed at training the next generation of dedicated land stewards and conservation scientists. The Continuum engages Chicago Public Schools students from diverse backgrounds in meaningful scientific research and mentoring programs from middle school through college and beyond. “Each level of the Continuum challenges students to improve their science skills, building on what was learned at the previous level and preparing them for the next,” said Kathy Johnson, director of teacher and student programs.

College First is a paid eight-week summer internship for up to 20 qualified students. Isobel Araujo, a senior at Whitney Young High School in Chicago, attended the College First program in 2011 and 2012. As part of the program, she did research on orchids and learned how to estimate budgets to fix hypothetical ecological problems. “It was definitely challenging, but it was awesome,” said Araujo, who plans to major in environmental studies.

During the school year, College First students also attend monthly meetings that help them select colleges, complete applications, and find financial aid to continue their education. More than 94 percent of College First graduates attend two- or four-year colleges, and many are the first in their family to attend college. Three students, including Robert Harris III, received full scholarships to universities beginning in fall 2013.

Harris is a freshman at Carleton College in Northfield, Minnesota. As a junior and senior at Lane Tech High School in Chicago, he made a three-hour daily round-trip commute to the Garden for the College First program. During his internship, he learned to extract plant DNA and study genetic markers in the Artocarpus genus, which includes breadfruit and jackfruit. Harris said the program was a great experience. “You get out of the city and experience nature close up,” he said. “The Garden itself is one big laboratory, and it was a lot more hands-on than in high school.”

PHOTO: An intern carries a quiver full of marking flags, and takes notes on her clipboard.

Science First and College First programs lead into other graduate and postgraduate programs. Visit chicagobotanic.org/research/training to find information on these programs.

PHOTO: A group of about 50 people pose at the end of the Serpentine Bridge.

Conservation and Land Management (CLM) postgraduate interns for 2013 pose for a group photo at the Garden. Visit clminternship.org to find out more about this program.

Because of funding restrictions, enrollment for the Continuum programs are limited to students from Chicago Public Schools. For more information, visit chicagobotanic.org/ctl/teacher_students or call (847) 835-6871.


This post was adapted from an article by Nina Koziol that appeared in the spring 2014 edition of Keep Growing, the member magazine of the Chicago Botanic Garden.

©2014 Chicago Botanic Garden and my.chicagobotanic.org

A well-designed outdoor space can do wonders for seniors and those with Alzheimer’s disease. But how do these gardens differ from other outdoor spaces and why are they so important?

Housing for the elderly has been provided in many western cities since the Middle Ages. Facilities such as independent living centers, skilled nursing homes, dementia or memory care units, and hospice facilities have traditionally included some form of outdoor space.

PHOTO: Book cover.

The Role of the Outdoors in Residential Environments for Aging, published in 2006.

The majority of the elderly (over 65) reside in their own home or with relatives. Whether in a facility or at a personal home, particular symptoms of decreased quality of life begin to show during these stages. These symptoms are often displayed in the form of boredom, helplessness, and loneliness. Fortunately, many, if not all of these symptoms can be improved with gardening and exposure to outdoor spaces.

The keys (and often the greatest challenges) to successful aging are to remain physically active and socially engaged, and to retain a sense of self. There are many measureable health outcomes for seniors and the outdoors. Even a short visit in a garden can lower blood pressure, improve vitamin D absorption, improve stability, and help with better sleep patterns.

Boredom can be remedied with sensory stimulation and interaction with nature. Nature can aid the feeling of helplessness with providing a space for temporary escape (actual or visual), and the feeling of loneliness can be decreased in a garden that provides multiple places for socialization.

The benefits are endless. So how do we make sure these wonderful gardens are implemented properly so that they will be used by seniors?

PHOTO: An elderly woman smelling a yellow rose and smiling.

A senior engages with colorful and inviting roses at Elm Tree Gardens in Lansdale, Pennsylvania.

For today, we’ll concentrate on four factors of design: The entrance and exit to the outdoor space, plant material, pathways and ease of accessibility (circuit and materials), and seating.

The entrance/exit to an outdoor space—the threshold—is perhaps the most important factor to consider when designing an outdoor space for the elderly, and this largely comes down to one single detail: the door. Doorways are high on the list of residential complaints. Often they’re hard to open, or locked. They don’t have windows and therefore inhibit visitors from viewing the garden (…what’s the weather like?). Perhaps the door has a lip that makes it difficult for seniors in wheelchairs to cross the threshold on their own.

Another factor involving the threshold is the comfort (or perceived comfort) when entering or exiting the garden. Creating a transition or “comfort zone” between the indoor and outdoor space is key. Aging eyes have difficulty adjusting from indoor light to outdoor sunlight. Providing shade at the entrance/exit in the form of an awning or patio will increase the transitional comfort.

This brings us to the next factor: plant material.  I didn’t mention a pergola with draping vines as a possibility for the transition space. That’s because it’s a detail that is strongly discouraged in outdoor design for seniors.  A pergola or draped plant material creates patterned shadows on the ground. This is referred to as “visual cliffing” in design. Seniors react to changes in paving color, or deep shadows on a path as if they were a change in depth. This may lead to stumbles, fear, and discomfort. Simply avoiding structures such as arbors or trellises will alleviate this issue.

Plant selection for the garden is fairly straightforward. Use a variety of trees, shrubs, flowers, and vines and place them where they can be touched and smelled. Aging eyes can see highly saturated colors—such as oranges, reds, and yellows—more easily than blues, purples, and greens. Also, certain plant material such as herbs and traditional shrubs (hydrangeas, roses, etc.) help to stimulate memory as they often bring deep-rooted and cherished memories to mind for those with Alzheimer’s disease.

Color choices are not just important when it comes to plant material, they’re also important for paving, our third factor. Since aging eyes have trouble with glare, use non-glare paving surfaces such as tinted concrete. Other satisfactory surfaces include rubberized asphalt and stabilized decomposed granite.

PHOTO: A brick garden path leads to a white gazebo in a circular garden.

A gazebo provides an easily accessible destination to garden visitors.

The pathway circuit is also pivotal. Creating interesting places to walk with shorter and longer loops, destinations points (such as a water fountain or gazebo), and changing vistas will encourage engagement and exercise. With these pathways, be sure to pay attention to safety. Pathways with edges or railings will ensure safety for wheelchair users or individuals with impaired sight.

It should be noted, however, that in a facility for those with Alzheimer’s disease, a destination point or wandering path should be adjusted so that its pathway circuit never takes an individual to a point where the entrance/exit is no longer visible. This may lead to the feeling of being “stuck” or agitated if confusion sets in. Not knowing which route to take or how to get back can be very stressful for someone with Alzheimer’s. Instead, create a series of large and small destinations and landmarks that will help users orient themselves in a space (flagpole, gazebo, group of chairs, etc.).

Lastly, think about seating. It is important to design different areas for seating to create options. Some may like an area to sit alone. Living with other people in a facility is a new experience for many residents and it can be stressful. A garden can provide a place for quiet contemplation. On the other side of the spectrum, there should also be places to sit with others. These spaces create socialization, either with visitors or among the residents.  

PHOTO: A lush urban garden has raised beds which provide seating, and a riot of colorful plantings.

Lush planting, smooth pathways, and seating areas enhance the quality of the experience in—and use of—any garden.

Consider also the kind of seating to be provided. Wood, fabric, or hard plastic materials are preferred, as they are more comfortable than steel, aluminum, or concrete surfaces. When possible, provide seating with cushions to increase comfort. Using moveable seating is also very popular. Use of the overall space skyrockets when people of any age are able to move or manipulate their seat for optimal comfort and satisfaction. This enables garden users to feel in control, which may be lacking inside the building.

These factors as well as countless others help to create spaces that are inviting and engaging to the elderly. There are additional factors to consider in an outdoor space that relate to programmatic intentions on top of the physical design but we’ll visit those topics another day.

Outdoor spaces in facilities for the elderly and aging are immensely important. The next time you visit one, take a moment for a quick assessment. With these basic tips, everyone can be an expert and wonderful advocate for successful outdoor spaces and gardens for the elderly. 


©2014 Chicago Botanic Garden and my.chicagobotanic.org

Mushrooms reproduce by making billions of spores that spread and grow into new organisms. You can take advantage of this phenomenon to make a beautiful print on paper.  

How to Make Spore Prints

All you need are some fresh, open mushrooms, paper, and a bowl. You can use mushrooms found growing outside or buy them from the market. When selecting mushrooms for spore prints, look for these things:

  • The cap should be fully open with the gills exposed
  • The gills should look good, not wet and mushy
  • The mushroom should feel slightly moist but not wet; dry mushrooms will not work
  • There shoud not be mold spots on the mushroom
  • They should look like mushrooms you want to eat
PHOTO: Underside of a portabella mushroom.

This portabello mushroom is good for making spore prints.

PHOTO: Shiitake mushroom.

This shiitake mushroom may be a little old—notice the brown spots on the cap’s edges—but should work.

First, you should remove the stems. I use scissors so I don’t pull up or damage any of the gills.

Place the mushrooms with the gill side down on a piece of paper. Mushrooms with dark gills, like portabellos, have dark spores that show up well on white paper. Shiitake mushrooms have white gills and spores that will show up better on black paper. Some mushrooms make both dark and light spore prints.

PHOTO: Mushrooms, gills down, sitting on black construction paper.

These four shiitake mushrooms were placed on black paper. They will be covered with a bowl and then left overnight.

Place the paper on a tray or other surface that can handle something wet sitting on it because moisture from the mushrooms will soak into the paper and anything underneath it. Cover the mushrooms with a bowl to prevent them from drying out. Really ripe mushrooms will make a print in an hour, but I suggest that you leave them overnight to be sure you get results.

In the morning, carefully lift your bowl and the individual mushrooms and see what you get. If the paper absorbed a lot of moisture from the mushrooms, it may need to dry before you see the print very well—especially prints made on black paper. Portabello prints often show well-defined gills. Shiitake gills are not as straight and rigid as portabello gills, so you’ll get less gill definition in the print and a more wavy, swirling print. If your mushrooms are too wet, or are starting to rot, you’ll get more of a watercolor effect instead of a sharp print.

PHOTO: Mushroom spore print.

If all goes well, billions of spores will fall from the mushroom and produce a pattern that resembles the gills on the underside of the cap, like this portabello mushroom print.

PHOTO: Mushroom spore print.

Four shiitake mushrooms leave ghostly impressions on black paper. The swirled edges were made by the uneven surfaces of the mushroom caps.

PHOTO: Mushroom spore print.

The fine lines on this print look like they might have been drawn by an extremely sharp pencil, but the spores that compose the image are much smaller than the tip of a pencil.

A Little More about Mushroom Spores

Garden scientist Louise Egerton-Warburton recently told me, “Plants are cool, but fungus rules.” As a mycologist, fungus is her passion. Now, we aren’t really interested in competition or ranking organisms by levels of interest or importance because every living thing needs the others to survive. But the fact remains that we tend to forget about smaller things, especially those that tend to be hidden from view, so let’s take some time to meditate on mushrooms.

PHOTO: Stinkhorn fungus.

This stinkhorn fungus, Mutinus elegans, is growing out of the ground, but that is where its resemblance to green plants ends. It’s named for its obnoxious odor, which attracts flies that help distribute its spores.

Scientists used to think of mushrooms and other fungi as special kinds of plants. The problem is that, unlike plants, fungi do not get energy from photosynthesis. They are composed of different kinds of cells, they complete a different life cycle, and let’s face it: they don’t really even look like plants. So fungi are now grouped in their own kingdom of organisms, and nobody expects them to be anything like plants.

There are many different kinds of fungus, so for simplicity, let’s just think about the familiar mushroom with its stem and cap. This structure is actually the reproductive part of the organism, in the same way fruit is a reproductive structure in plants. (But we are not comparing plants and fungus!) Beneath the soil where you find mushrooms growing, there is a network of branching thread-like structures, called “hyphae,” which grow through the dead plant and animal matter in the soil and absorb nutrients. This is the main “body” of the fungus. As the fungus digests organic matter, it decomposes, making it useful for plants.

PHOTO: Laetiporus sulphureus fungus, or "Chicken of the Woods".

This “chicken of the woods” fungus, Laetiporus sulphureus, doesn’t look like a mushroom, but it also produces spores.

PHOTO: Mushrooms decomposing bark on the forest floor.

The fungus that produces these mushrooms is decomposing leaves and sticks that have fallen to the forest floor.

Back above ground, when conditions are favorable, a mushroom grows up from the hyphae. It matures and releases spores, which are like seeds. (It’s really hard to get away from comparing fungus with plants!) Spores are structurally different from seeds, even though they function to spread the organism in a similar way. Spores are microscopic and are so small that mycologists measure them in microns. A micron is one millionth of a meter.

PHOTO: A ruler measures the tip of a pencil lead.

How many spores could fit on the tip of a sharp pencil? A lot! No wonder the spore print is so fine and delicate!

Look at a metric ruler. See the smallest lines that mark millimeters? Imagine dividing a millimeter into one thousand equal parts. Fungus spores measure 3 to 12 microns. It hurts my eyes trying to imagine a spore sitting on my ruler. We can only see them when there is a mass of them on a spore print. Mycologists use a micron ruler built into their microscopes to measure the individual spores.

Tiny but essential: Fungus rules.

©2014 Chicago Botanic Garden and my.chicagobotanic.org

“But wait! There’s more!”

Lenhardt Library Treasures Populate Exhibitions

Amy Spungen —  February 13, 2014 — 2 Comments

Stacy Stoldt is never not working on an exhibition.

Even when the Lenhardt Library’s public services manager is staffing the desk, answering reference questions, and locating articles for staff, the “million and one” details involved in putting together the library’s four annual rare book exhibitions are percolating in her brain.

PHOTO: Stacy Stoldt organizing bookshelves.

Stacy Stoldt awaits patrons in the Lenhardt Libary.

Stoldt has streamlined the process since she first began working at the Chicago Botanic Garden in 2007, but it remains a lot of work to curate an exhibition. “There’s the research, the writing, the editing, the design, the approvals,” she said last month. “Here we are in January, and we’re in the design phase of our next exhibition, which opens in February, but back in November I was already meeting with someone about books for an exhibition that opens this May. There’s always a deadline looming.”

Stoldt loves her work, and one of her chief pleasures is deciding which literary treasures will be selected. It is a process involving research, more research, and finally, she says, just a bit more research. The excitement of finding the perfect volume has prompted Stoldt to burst into song (just ask cataloger Ann Anderson, a neighbor in the basement office who sometimes joins in).

The public services manager and her colleagues have many volumes from which to choose: in 2002, the Lenhardt Library acquired a magnificent collection of 2,000 rare books and 2,000 historic journals from the Massachusetts Horticultural Society of Boston.

An Exhibition Takes Shape

PHOTO: A meeting with a dozen people gatherered around rare books.

Stoldt shows rare books to a group in the rare book reading room.

Before Stoldt begins hunting down books, there are meetings to decide Lenhardt Library exhibition topics for the year. That process begins with a brainstorming session including Stoldt, Lenhardt Library Director Leora Siegel, and Rare Books Curator Ed Valauskas. Sometimes the trio bases their topics on themes within the collection, such as the upcoming succulent show that features the work of A.P. de Candolle and botanical-rock-star-illustrator Pierre-Joseph Redouté.

Alternatively, they might collaborate with another botanical library on a theme, as happened when the Lenhardt Library team worked with the New York Botanical Garden’s LuEsther T. Mertz Library on the recent exhibition Healing Plants: Illustrated Herbals. Other times, they select topics that complement events held at the Garden, such as Butterflies in Print: Lepidoptera Defined, which ran in conjunction with last summer’s Butterflies & Blooms.

Newest Exhibition Focuses on Orchids

PHOTO: An illustration of Masdevallia coccinea from an illustrated book panel.

The Lenhardt Library’s newest exhibition, Exotic Orchids: Orchestrated in Print, runs through Sunday, May 11. This image is from Xenia Orchidaceae: Beiträge zur Kenntniss der Orchideen, by Heinrich Gustave Reichenbach.

The newest Lenhardt Library exhibition complements the Orchid Show and is titled Exotic Orchids: Orchestrated in Print. Running through Sunday, May 11, it features such rare books as Charles Darwin’s seminal On the Various Contrivances by which British and Foreign Orchids are Fertilised by Insects, and on the Good Effects of Intercrossing, published in 1862. Another item is Curtis’s Botanical Magazine, with a beautiful color illustration of Angraecum sesquipedale, also known as Darwin’s orchid. “One doesn’t come alive without the other,” said Stoldt. “I’m always trying to put the connections together for people.”

For some exhibitions, Stoldt does it all—A to Z. For others, she receives the researched text, citations, and selected illustrations from Valauskas or Siegel and develops the material into an exhibition. Once the topics are established, research is completed, and explanatory text is written and edited, graphic designers enter the picture. Stoldt selects images from the featured books to use with the accompanying text, and then the designers work their magic. Along the way, Stoldt and Siegel review the progress. The result is an exhibition compelling not only for its content but for its elegant layout, which extends throughout the display cases that greet visitors as they enter the library.

Accompanying library talks are on Tuesday, February 18, and Sunday, March 9, at 2 p.m.

“For our new Exotic Orchids exhibition, we really wanted to show some bling!” said Stoldt. Within the Rare Book Collection, there was so much to choose from on orchids that she found the selection process daunting. Visitors to the exhibition will find the beauty and science of orchids well-represented, and discover items about orchid conservation and preservation as well.

Art Conservation Key to Documenting Plants

Stoldt noted that conserving the books and the artwork that document a plant’s existence is almost as important as preserving the actual plant. In cases two and three of Exotic Orchids, there are select illustrations from two orchid collections, Les Orchidées (1890) and Les Orchidées et les Plantes de Serre (1900–10), which the Lenhardt Library recently had conserved by the Northeast Document Conservation Center (NEDCC) through grant funding from the National Endowment for the Humanities (NEH).

How did the conservation process work? Professionally trained book and paper conservators removed the illustrations from their original acidic bindings; then the inks were tested, the surfaces were cleaned, and the illustrations were digitally photographed. Then the illustrations were placed in chemically stable folders and housed in custom-made boxes made from lignin-free archival boards. Conservation completed!

ILLUSTRATION: An unidentified Cypripedium, or slipper orchid.

Cypripedium VIII. color plate

The Rare Book Collection

Stoldt recently brought out some rare volumes to demonstrate the variety within the Rare Book Collection. As noted on its web page, the collection reflects a relationship between people and the plant kingdom that has been documented since the earliest days of print, when botanists were not simply plant describers, but explorers.

Out came volume after volume, with Stoldt pointing out noteworthy details about each. Among them was the oldest book in the collection, Historia Plantarum, written by Theophrastus (d. 287 B.C.E.) and published in 1483 (it has some unusual marginalia). There was also an exquisite Japanese book on flower arranging, Nageire Kadensho: Saishokuzu Iri, published in 1684 and donated by longtime library volunteer Adele Klein. Stoldt continued her informal presentation with seemingly boundless enthusiasm, finishing with lush life-size images from The Orchid Album, published between 1882 and 1897.

More than once, Stoldt returned a book to the vault at the end of the show-and-tell only to call, “but wait! There’s more!” as she glimpsed another book she absolutely had to show. This librarian really, really loves her books. And she feels very protective of them.

Stoldt recalled the horror she felt once when she was installing an exhibition, with a rare book exposed nearby on a book “cradle”: “There was a sign that said ‘Exhibit installation in progress: please do not touch the rare books,’ but this person came in from the rain and loomed over it, dripping wet. I got her out of the way, but that was a close one.”

Cultivating Relationships

More often, visitors are sensitive to the delicate state of the Garden’s rare books. Some Garden members make a point of coming to each new exhibition and attending the free gallery talk. “One patron always calls from Wisconsin to find out about the next talk,” said Stoldt. “And once, a library regular who came to a talk told me how much she loved the book Brother Gardeners [about eighteenth-century gardeners who brought American plants to England]. I was able to show her some books by the book’s featured plantsmen, including Joseph Banks, John Bartram, and Phillip Miller, among others. It’s what I call an ‘on-demand rare-book viewing.’ She was thrilled. These are the kinds of things that lead to relationships with people.”

Devoted patrons feel that the library and its exhibitions enhance their lives; in turn, some are moved to enhance the Rare Book Collection. “We have our patrons, and then we have our patron saints,” said Stoldt. One patron who came to the 2009 exhibit on Kew Garden’s 250th anniversary enjoyed the accompanying talk by Ed Valauskas so much that she donated the 1777 edition of Cook’s Voyage, or A Voyage Towards the South Pole, by Captain James Cook, which had been in her family for family for decades. And longtime members John and Mary Helen Slater made it possible for the library to acquire 11 volumes of Warner’s Orchid Album.

Inspiring the Next Generation

Stoldt loves to see the excitement she feels about the Garden’s Rare Book Collection spreading to a new generation. She recalled a day when a grandfather brought his grandson to the library, and the child asked to see a rare book. “I asked him what he was interested in, and he said, ‘poisonous plants.’ First, I showed him Histoire des Plantes Vénéneuses et Suspectes de la France by Bulliard, a book on poisonous plants written in French from the eighteenth century, but what really spoke to him was a book with the ‘coolest illustrations!’ entitled Poisonous Plants, Deadly, Dangerous and Suspect, Engraved on Wood, 1927, by John Nash. This kid was just amazed. I love seeing young readers light up when they’ve found something intriguing for them in print. It’s heart-warming.”

ILLUSTRATION: Cattleya aclandiae.

Cattleya aclandiae from a rare book color plate

Although that particular drop-in visit and viewing request occurred on a busy weekend day, another library staff member was available to manage the circulation desk while Stoldt showed the books. “I can’t stress enough the importance of making an appointment for a viewing,” she said. “Besides kids, grandparents, and garden clubs, people from all over the world come to Lenhardt Library to see primary resources they can’t find elsewhere. We’ve had writers and scholars from England and the Netherlands, and even a Thai princess, come to see the Rare Book Collection. Everyone is welcome.”

Don’t be surprised if you come to see one specific book in the collection and end up seeing many more. It will be a visit you won’t forget!

Rare book viewings are by appointment only during the hours of 10:30 a.m. until 3 p.m. Monday through Friday, subject to availability. For an appointment, call (847) 835-8201.

The Orchid Show is open through March 16, 2014. Click here to purchase tickets online.


©2014 Chicago Botanic Garden and my.chicagobotanic.org

While you are inside wondering if winter will bring another chilling polar vortex, or six feet of snow, or 40 degrees Fahrenheit and rain, join me in contemplating the sweetness of plants.

PHOTO: Burgundy leaves of the Bull's Blood sugar beet.

The common sugar beet, Beta vulgaris (this one is cultivar ‘Bull’s Blood’), is the source of our refined white sugar—not sugar cane!

All sugar comes from plants. All of it. Plants are the only thing on earth that can make sugar, and plants are made of sugars. Even plant cell walls are composed of a substance called cellulose, which is a compound sugar. Sugars from plants are the basis of our food chain.

Our favorite dietary sugar, sucrose, comes from the juices of sugar cane or sugar beets, which are boiled until the water evaporates, leaving the sugar crystals we all know and love as table sugar. Now that you know where your candy comes from, let’s use some sucrose to make a treat.

How to Make Rock (Sugar) Candy

Rock candy is pure, crystallized sucrose, and you can make it at home. This will take one to two weeks, so get started now if you want to give it to someone special for Valentine’s Day.

You will need

  • 1 cup water
  • 3 cups sugar, plus about a spoonful extra to coat the skewers
  • Food coloring (optional)
  • Flavoring (optional)
  • Bamboo skewers
  • Very clean, heat-resistant drinking glasses or glass jars (like Ball or Mason jars)
  • 2 clothespins
PHOTO: Tools and ingredients for making rock sugar candy laid out on the kitchen counter.

All the ingredients for the solution are assembled and ready to go. Note: the flavoring pictured here is not the best to use, because it contains alcohol. Use an essential oil for better results.

Directions

First, assemble the hardware. Cut the bamboo skewer to 6–8 inches, depending how long you want it. Attach two clothespins to one end. They will rest on the edges of your glass, suspending the skewer straight down in the glass without allowing it to touch the sides.

Cut a piece of paper towel with a hole in the center. This will go over the top of your glass to prevent dust from settling on the surface of the solution. Remove the paper towel and skewers; you’ll reassemble this after you’ve poured the solution in the glasses.

PHOTO: Glasses and skewers set up for making rock sugar candy.

Suspend the skewers using one or two clothespins as pictured here, and be ready to cover loosely with a piece of paper towel like the glass shown in the middle.

Important tip: The directions I followed (from a reputable source) instructed me to moisten the end of the skewer with water and roll it in some sugar to “seed” the formation of new crystals. When I tried this, the sugar crystals all fell off the skewer the minute I put them into the solution. Crystals will not grow on a bare skewer. What did work was dipping the skewer into the sugar solution (which you are about to make) and then rolling it in sugar. This kept the tiny sugar crystals stuck on the skewer and allowed larger crystals to grow.

Making the sugar solution. Pour 1 cup of water in a saucepan and heat to boiling. Then turn the heat to low. You do not want to boil the water after you have added sugar, or you will make a syrup that is stable and will not yield crystals. Add the 3 cups of sugar gradually, and stir to dissolve. Push down any crystals that form on the sides of the saucepan during heating to dissolve in the water. This takes some time! Your final solution should be clear—not cloudy at all—and you should not see any crystals.

PHOTO: Green-dyed rock sugar candy solution in a Mason jar.

You can choose to pour the liquid into two small glasses or one larger jar.

If you want to color or flavor your candy, now is the time. Add 2 to 3 drops of food color and/or 1/2 tsp of food-grade essential oils (like peppermint), and stir in thoroughly. Avoid using alcohol-based extracts like the bottle you see pictured in the blog. I’m not sure if this caused a failure during one of my trials, but I can say with certainty that I had better results when I used a flavoring oil.

Dip the end of the skewer a few inches into the solution and remove. Let the excess sugar water drain into the pot, and then roll the sticky end in dry granulated sugar to coat evenly. Set aside.

Pour the warm solution into the glass container(s), and fill to the top. With this recipe, you will get about 3 and 1/2 cups of solution, which will fill one jar or two glasses. You can scale the recipe up if you want more.

PHOTO: Rock sugar candy skewers.

After about eight days, you can see the cube-shaped sugar crystals on these skewers. The longer you leave them in the solution, the larger the crystals will grow.

Carefully lower the sugar-coated skewer into the solution, holding it in place with the clothespins. Cover lightly with the paper towel and place it in a safe location where nothing will bump it or land in it for at least one week—two weeks if you want larger crystals. Do not totally seal your glass or jar. The water needs to evaporate for the sugar to come out of solution and crystalize on the skewer. If all goes well, then over the next week you will see large crystals forming only on the skewer.

Got candy? Remove the skewer and drain the syrup. Eat immediately, or allow to dry, wrap in plastic, and save for later. Now that is what I call cultivating the power the plants!

One more thing: You can use string instead of a stick. Tie a small weight on the bottom and tie the top to the a pencil balanced on top of the glass so that the string hangs in the liquid.

PHOTO: A weighted string coated in rock sugar crystals.

The string was weighted with a metal nut so it would sink into the solution.

While you are waiting for your sucrose to crystalize, let’s contemplate where it came from.

Sugar from Plants

You probably know that plants harness energy from the sun to convert water and carbon dioxide into sugar and oxygen in a process we call photosynthesis.

PHOTO: diagram of a plant showing carbon dioxide and light energy entering the plant leaf andwater entering through the roots, while glucose is formed in the leaf and oxygen is released into the air.

This basic diagram shows photosynthesis in action.

The product of the reaction is a sugar called glucose, which is chemical energy that a plant can use to build plant cells and grow. The formula looks like this:

6CO2 + 6H2O (+ light energy) C6H12O6 + 6O2.

Translated, it means that inside plant cells, six carbon dioxide molecules and six water molecules combined with energy from the sun are converted into one sugar molecule and six oxygen molecules.

Glucose molecules are combined to form more complex sugars. Sucrose, or table sugar, has a molecular formula C12H22O11.  It looks like two glucose molecules stuck together, but missing one oxygen and two hydrogen atoms (or one water molecule).  

ILLUSTRATION: Sucrose molecule.

This sucrose molecule looks good enough to eat!

PHOTO: Sugar cubes.

Just kidding. It looks better in normal scale.

As I mentioned earlier in this post, plants are the only thing on earth that can make sugar. Through modern chemistry, food scientists have figured out how to extract and modify plant sugars more efficiently. They have also developed different kinds of sweeteners, because the food industry is always striving to develop less expensive ways to satisfy our craving for sweets, as well as supply alternative sweeteners for different dietary needs. Some sugars you may see on food labels include dextrose (which is another name for glucose), sucrose, fructose, high fructose corn syrup, maltose, and sucralose. All of these “natural” sweeteners were processed from plants, even though they do not exist without help from a laboratory.

Have you noticed that all of these sugars, including the sugars in plant cell wall structures, have names that end in “ose”? That is no accident. The suffix “ose” is the conventional way chemists identify a substance is a sugar. Go ahead, share that information at your next party as you consume goodies made from plant sugars. Having some chemistry facts at your sticky fingertips makes you sound smart while you’re nibbling on sweet treats.

PHOTO: Fresh produce in a wicker basket.

Yum!

Please enjoy sucrose crystals responsibly, as part of a balanced diet that includes forms of sugars closer to their origins. (In other words, eat fruits and vegetables, too.) And remember to brush your teeth!


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