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These posts offer previews or behind-the-scenes information on some of the Garden’s special events. Learn what it takes to put together these exquisite events and then come see them in person!

How to Grow More Amazing Dahlias Than Your Neighbors

A Dahlia Primer: From Planting to Blooming

Guest Blogger —  August 4, 2017 — 1 Comment

Get ready for an explosive burst of color September 9-10 at the annual American Dahlia Society National Show at the Chicago Botanic Garden. More than 2,000 flowers in the dahlia family will be on display in a wide variety of colors, sizes, and forms. 

Dahlias are indigenous to Mexico, where they were grown by the Aztecs, who used the tubers as one of their staple foods. The plants were brought to Spain and eventually spread throughout Europe, as people appreciated the beauty of the flowers themselves. Through hybridization, there now are more than 70,000 varieties of dahlia, about 1,500 of which are popularly grown.

Here are some tips for growing these beautiful plants in the garden. 

Dahlia bouquet from the American Dahlia Society National Show

ILLUSTRATION: dahlia artOn September 9 and 10, the Central States Dahlia Society and the Chicago Botanic Garden present the 51st annual American Dahlia Society National Show. For detailed information on the show and the Central States Dahlia Society, please visit centralstatesdahliasociety.com


Selecting a site

Pick a sunny spot where, optimally, the plants will receive at least six hours of sunlight. Since dahlias do not like to get their “feet” wet, the area should not accumulate water and should drain well. If the soil is clay-like, it should be amended with leaf mulch, compost, or peat moss. Since dahlias should be planted about 18 inches apart, it is easy to determine the number of plants the area will accommodate.

Planting

You can plant your dahlias as soon as the danger of frost has past, and the soil temperature remains above 55 degrees Fahrenheit. In Chicago, this typically means about the middle of May. However, some growers wait until Memorial Day just to be sure. The delay does not seem to appreciably affect when the first blooms appear. You can start with either potted plants or tubers that have been over-wintered from last year’s crop.

If using potted plants that have already developed a root system, place the plants in the ground so that the top of the potting medium is level with the ground. Many growers will add a slow-release fertilizer (e.g., Osmocote) and/or composted manure to the bottom of the hole. Water the plants once they have been put in the ground, and water as needed to keep the soil moist (about one inch per week).

Planted dahlia tuber

Planted dahlia tuber

A new dahlia plant

A new dahlia plant

When starting with tubers, dig a shallow hole (about 6 inches deep), add material as described above, and place the tuber on its side. Loosely cover the tuber—but do not bury it—with soil. Once the tuber has sprouted and the sprout has reached the level of the soil, the hole should be back-filled. The tubers should not be watered until they have sent out a sprout that reaches above ground level. A word of caution: Tuber sprouts can be quite delicate. It is a good idea to use a short, temporary support until the plant becomes established. You can start with tubers planted directly in the soil or start the tubers indoors in pots to get an early start. If starting inside, the tender plants should be “hardened” off prior to planting in the garden.

Since dahlias will often grow to five feet or more in height, they need to be staked. The stake should be placed in the ground as soon as the plant, or tuber, is in place. Put the supporting stake within a couple of inches of the plant and avoid damaging the tuber. Plastic stakes tend to bend and break. Many growers use ¼- to ½-inch rebar that can be bought from big-box stores or building supply centers. Tomato cages also provide good support.

New dahlia plant staked, tied, and identified

New dahlia plant staked, tied, and identified

Depending on the height of the plant, you should loosely tie it to the supporting stake. The final step in the planting process is to write the name of the variety on a plastic tag. The tag should be stuck in the ground or attached to the support system.

Dahlia bed ready for the growing season

Dahlia bed ready for the growing season

The first several weeks

As the plant continues to grow, additional ties will have to be placed at about 12-inch intervals. After the plant produces three or four sets of leaves and is about 18 inches tall, the plant should be “topped.”  This means that the terminal bud, at the top of the main stem, must be removed. This will be done only once. This process forces that plant to develop lateral stems, which results in more flowers. 

A "topped" dahlia with terminal bud removed, and laterals forming

A “topped” dahlia with terminal bud removed, and laterals forming

Water as needed to keep the soil moist. During this early phase, many growers will use a nitrogen fertilizer to promote leaf growth and stimulate the plant’s development.

Once buds appear

Depending on the weather and maturity of the starting stock, after about six to eight weeks the first buds should appear. These will develop in groups of three. Two of these should be removed. This process, called “disbudding,” will result in larger blooms. The first blooms tend to be the largest ones that the plant will produce. Growers who plan to compete in shows will try to time these first blooms so they appear just before the show.

A dahlia plant ready for "disbudding"

A dahlia plant ready for “disbudding”

During this phase, water the plant as needed. Watering should be done at the base of the plant. Water on the leaves may cause disease, and water on the blooms may cause them to become top-heavy and droop, or even break. Fertilizing during this phase should consist of potassium and phosphorus to encourage root and bloom development. Do not “over-feed’ the dahlias. Fertilizing about every three to four weeks is the generally recommended practice.   

If the plant becomes too full, you should remove a lateral stem or two. This process, called “disbranching,” should be done as close to the main stem as is possible. All plant grooming should be done in the early morning.  Ideally, you should sterilize the cutting tool as you move between plants to avoid the possible transfer of any disease for one plant to the next.

During the growing season, be aware of the impact of pests and plant disease. Snails and slugs may attack the newly planted dahlias. Spider mites are the most common pest. If they attack, the leaves will shrivel and yellow spots will appear. Many growers will preventatively spray once the hot weather arrives to avoid these pests, as remediation is difficult.

A garden full of dahlias

The fruits of your labor

Cutting the blooms

It is best to cut the blooms in the morning using a sharp instrument to make a clean cut. The stem can then be slit along its length to increase water absorption. Freshly cut dahlias will last in the house for one week or longer. 

 

By George Koons, Central States Dahlia Society


©2017 Chicago Botanic Garden and my.chicagobotanic.org

Don’t trust your eyes—that leaf is actually a butterfly

The orange dead leaf (Kallima inachus)

Patrick Sbordone —  July 20, 2017 — 2 Comments

As the season has been progressing at Butterflies & Blooms at the Chicago Botanic Garden, we have been lucky enough to receive a very special butterfly species and a definite crowd-pleaser: the orange dead leaf (Kallima inachus)

If we didn’t point out this character to guests, no one would ever suspect that they were looking at a butterfly.

I like to describe the orange dead leaf butterfly as being able to mimic a dead leaf better than an actual dead leaf can. When it closes its wings, the butterfly has a perfectly ovate silhouette, complete with both a pointed leaf apex at the front tip and a petiole, or the stalk that attaches leaf to stem, on the hindside. The wing is a drab brown, with leaf vein arrangement very similar to that of a flowering dogwood. The orange dead leaf butterfly is at home in broadleaf forests of India, where it blends in with dead foliage during the dry season, going unnoticed by all but the sharpest predators. Here at Butterflies & Blooms, this butterfly seems to seek out dead, brown leaves in the tree canopies and uses them as a place to blend in. I always get a kick out of showing people that one of those dead leaves is not what it seems.

Kallima inachus at rest on a branch

Kallima inachus at rest on a branch

Kallima inachus with its wings open

Kallima inachus with its wings open

The butterfly has another surprise for visitors: It has incredibly vivid coloration on the dorsal side of its wings. When the orange dead leaf opens its wings to sun itself or take flight, it shows off its navy blue iridescent wings, with a bright orange stripe on each of the forewings.

We have several other butterfly species that also use one side of their wings to resemble dead foliage, including the autumn leaf (Doleschallia bisaltide) and the great orange tip (Hebomoia glaucippe). However, these species have not mastered the art of camouflage quite like Kallima inachus. Come over to Butterflies & Blooms to check out this fascinating butterfly.


Atlas moth (Attacus atlas)

Atlas moth (Attacus atlas)

While you are here, take a look at the serviceberry tree just to the left of the pupae chamber. We have an unprecedented seven giant atlas moths perched on the tree branches like Christmas tree ornaments. Also, don’t miss all of the blooms: The recent rainy weather has undoubtedly helped the Butterflies & Blooms garden become more floriferous.


©2017 Chicago Botanic Garden and my.chicagobotanic.org

USO families and veterans were welcomed on June 25 to a special day at the Chicago Botanic Garden. A gift from the Annie and Gregory K. Jones family provided the families and veterans with a day of fun experiences: tram tours, admission to the Model Railroad Garden: Landmarks of America and Butterflies & Blooms exhibits, lunch, exploration at the Kleinman Family Cove, nature play at the Regenstein Learning Campus, and creating a mini terrarium in the Buehler Enabling Garden. 

The Garden’s horticultural therapy department drew on their experiences working with veterans and their families as they planned a plant-based activity that would celebrate the strengths of these folks. Succulent plants were a natural choice. Add colored aquarium gravel and a portable container, and you’ve got a beautiful tribute to the pride of being a member of a military family. So, here is a fun way to consider this event:

How is a plant like a member of a military family?

Succulent plants

Succulent plant: By deftly storing water, succulent plants live just fine under extremely hot and dry conditions.

Military family holding small terrariums made at the Garden.

Military spouse: By using resources wisely, a military spouse stretches money, time, and love to make sure the whole family is taken care of, wherever they may be.

Succulent plant

Succulent plant: Develops a tough exterior to endure harsh conditions.

Military family eating lunch at the Garden's USO Military Appreciation Day.

Military parent: Develops coping skills and the ability to play both mom and dad roles to endure long deployments.

Succulent plants

Succulent plants: So many colors, leaf shapes, growth habits, and unique beauty—yet all have key traits in common.

Military family eating lunch at the Garden's USO Military Appreciation Day.

Military kid: Powerfully diverse in appearance, personality, and beauty—yet all have key traits in common.

Succulent plant

Succulent plants: Belong to many plant families, but all are classified as succulents because of the features they have in common.

Military family holding small terrariums made at the Garden.

Military families: Each family is unique, and many include extended family members for support, yet each family takes pride in—and draws strength from—the traditions, support, and high purpose that being part of the military offers.

One striking thing about the day was the eager participation of everyone who planned and worked on that day. Garden volunteers raced to sign up for shifts. Many cited their own family members in service and their strong desire to honor those who keep us safe and free. The USO of Illinois had an equally eager corps of volunteers who came to the Garden early on a Saturday morning to get the “goodie bags” filled and to register everyone. 

Kay Knight, horticultural therapy coordinator, was the Garden’s point person for planning the day. Kay worked with departments across the Garden and with USO of Illinois to make sure everything ran smoothly. According to the many, many compliments and thanks expressed, Kay succeeded! 

The USO families had fun doing activities together and enjoyed the red-carpet treatment. 

 


©2017 Chicago Botanic Garden and my.chicagobotanic.org

Flora Brasil

Lenhardt Library celebrates Brazil in the Garden with a “Flora Brasil” special collections exhibition

Leora Siegel —  July 7, 2017 — Leave a comment

Brazil’s native flora has amazing diversity with differing biomes, including tropical rainforest, subtropical forest, tropical savanna, mangrove forest, tropical dry forest, wetland, and savanna.

Of the approximate 400,000 known plant species in the world, 55,000 are endemic to Brazil, and most of these are from the Amazon forest.

Brazilian bromeliads in the Crescent Garden

Bromeliads abound this summer throughout the Garden. There are more than 3,000 known species of bromeliads; 650 of these are native to Brazil. Many bromeliads have leaves that are spiraled and called a rosette. At the base of the rosette, the leaves may grow in an overlapping and tight form to become a place for water to collect.

Many of the foods we eat (like acai), industrial products we use (rubber tree and mahogany), medicines—even our houseplants in the Chicago region (orchids), depend on plants from this region. The unique flora of this area continues to be threatened by deforestation and urbanization, and plant species are at risk.

Books on display through October 15, 2017, in the Lenhardt Library’s Flora Brasil exhibition depict a plant exploration map, Brazilian aroid, and Brazilian bromeliads. An untitled original artwork by Brazilian landscape designer Roberto Burle Marx on loan from Longwood Gardens complements our main Joutras Galley exhibition of Marx’s work.

Roberto Burle Marx, Untitled, 1991, Courtesy of Longwood Gardens

Roberto Burle Marx, Untitled, 1991, Courtesy of Longwood Gardens

The library exhibition opens with an eighteenth-century map of South America with “the coast of Brazil being corrected” bound into the third edition in English of Voyage to South America: Describing, at Large, the Spanish Cities, Towns, Provinces on That Extensive Continent by Don Antonio de Ulloa and Don George Juan, 1772. Ulloa and Juan explored the region, observing and describing the flora, fauna, geology, minerals, indigenous population, and politics they encountered.

Map of a voyage to South America by Ulloa and Juan, 1772

18th century map of South America with “the coast of Brazil being corrected” from Voyage to South America: Describing, at Large, the Spanish Cities, Towns, Provinces on That Extensive Continent by Ulloa and Juan, 1772; Click here to view larger image

ILLUSTRATION: Philodendron cannaefolium by Heinrich Schott

Philodendron cannaefolium ‘Burle Marx’, a 24” x 30” detailed chromolithograph that is both scientifically accurate and stunning from Aroideae Maximilianae by Heinrich Schott, 1879.

A Brazilian aroid Philodendron cannaefolium (today known as Philodendron ‘Burle Marx’) is the centerpiece with a 24-inch-by-30-inch detailed chromolithograph that is both scientifically accurate and stunning. This 1879 work, Aroideae Maximilianae by Heinrich Schott, features 42 plates with delicate colors and clean lines. Schott was an Austrian botanist who traveled in Brazil from 1817 to 1821. He specialized in Araceae and throughout his career, he named 587 new-to-science species of aroids; by comparison, Linnaeus named six aroid species. 

Come also learn about Margaret Mee, who was an exceptional botanical artist, plant explorer, and environmentalist. Four reproductions of Mee’s “Brazilian Bromeliads” are on view. These are from a limited edition set published in Brazil in 1992.

Mee traveled to Brazil often, and went on fifteen botanical expeditions, mainly into the Amazon region. On these expeditions, she discovered several new plant species, painted more than 400 gouache pieces, and kept travel diaries detailing her adventures. Her passion for Brazilian flora coincided with the large-scale commercialization of the Amazon rainforest. She became an outspoken environmentalist, calling attention to the dangerous destruction of the biodiverse region. 

ILLUSTRATION: A Brazillian bromeliad by Margaret Mee

Margaret Mee’s Nidularium innocentii from Brazilian Bromeliads, reproduction, limited edition set published in Brazil, 1992.

Noted Brazilian landscape architect Roberto Burle Marx cultivated plants that Mee brought back from her expeditions and used them in his landscape designs. Known for his bright and bold color choices, Marx was inspired by Mee’s paintings. Like Mee, he was concerned about the environmental impacts of the commercialization of the Brazilian Amazonian region.

Learn more about Mee, Marx, and Brazilian flora at our free Library Talks on July 16, August 22, and September 12 at 2 p.m. in the Lenhardt Library.


©2017 Chicago Botanic Garden and my.chicagobotanic.org

Butterflies & Blooms has moved to the Regenstein Learning Campus and I have good feeling it’s going to be the best season yet, because we currently have a plethora of butterfly species native to Brazil. The Chicago Botanic Garden is celebrating Brazil in the Garden this summer, and Butterflies & Blooms is part of the celebration. 

Since we first opened Butterflies & Bloomswe have sought to display the most beautiful butterflies in the world, both exotic and domestic. Naturally, the Amazon rainforest is one of the most biodiverse regions on the planet. A whopping 60 percent of this precious treasure lies within Brazil. Brazil is home to thousands of butterfly and moth species (in comparison, all of Europe has about 300 species), and scientists have only recorded a fraction of the Lepidoptera species of Brazil and the greater Amazon rainforest.

You can find dozens of butterflies native to Brazil and neighboring countries in the exhibit on any given day. Currently, we have beauties such as the giant owl butterfly (Caligo memnon) and its close relative, the forest mort bleu (Caligo eurilochus). These two butterflies are often confused with moths because of their earth-toned camouflage and also because they are usually found resting on a shady tree branch during the heat of the day.

Large tiger butterfly (Lycorea cleobaea)

The large tiger butterfly (Lycorea cleobaea) thrives in the tropical rainforests of Brazil; find it here in Butterflies & Blooms. Photo ©Anne Belmont.

Blue morpho (Morpho peleides)

One of our most popular butterflies, the blue morpho (Morpho peleides) is another Brazilian native. Photo ©Anne Belmont.

Another pair of Brazilian butterflies that grace the exhibit are the grey cracker (Hamadryas feronia) and the starry cracker (Hamadryas laodamia), They are aptly named, since they can clap their wings while flying in order to make a percussive cracking sound as a means of communication. They use this talent when predators approach, to declare territory, and, of course, for mating. While the grey cracker blends into its environment with its intricate, drab coloration, the starry cracker is very showy, coated with brilliant blue specks on a dark blue field. Looking at it can feel like looking up into a starry night.

At Butterflies & Blooms, you can always find at least a few different species of longwing butterflies (Heliconius). Longwing butterflies have been extensively studied since Victorian times, because they display numerous forms of mimicry. In the late nineteenth century, the naturalist Henry Walter Bates traveled to Brazil and studied these butterflies. He noticed that Heliconius erato would mimic the coloration of other Heliconians, because they were poisonous. This particular form of mimicry was coined  “Batesian mimicry” after the naturalist. When Bates returned from Brazil, he used his findings to help support Charles Darwin’s theory of evolution.

Postman butterfly (Heliconius erato)

One of the longwing butterflies common to Brazil is the postman butterfly (Heliconius erato). Photo ©Anne Belmont

Another naturalist by the name of Fritz Müller observed what became known as “Müllerian mimicry”—also while studying longwings in Brazil. In this case, he noted that multiple species of poisonous butterflies will adopt the same coloration, making it easier for them to be recognized as poisonous would-be predators. Müller’s studies also led him to support Darwin’s theory of evolution.

The Amazon rainforest continues to be a scientific cornucopia to this day. The next time you visit Butterflies & Blooms, check out the owls, crackers, and longwings, and remember that they all represent the natural wonders of the Amazon rainforest and Brazil. Then take a walk through the Garden to discover more of the vibrant plants and colors of Brazil.


©2017 Chicago Botanic Garden and my.chicagobotanic.org