Archives For What’s in Bloom

Find out what’s in bloom now so you have plan your visit!

“The wonder of the world, the beauty and the power, the shapes of things, their colours, lights and shades—these I saw. Look ye also while life lasts.” —Anonymous lines found on an old tombstone in Cumberland, England

“While life lasts.” This can be a very brief moment in time for a spring ephemeral. In that narrow window that exists between thawing ground and the leafing out of the tree canopy, spring ephemerals—those woodland wildflowers that emerge, then quickly go dormant—live their life.

White trout lilies (Erythronium albidum)

White trout lilies (Erythronium albidum)

If you want to see some of the spring woodland flowers in bloom, you often have to be there on the day. In the McDonald Woods at the Chicago Botanic Garden, sometimes all you find are petals scattered on the ground, and you realize you have to wait another year. This is particularly true of species like bloodroot (Sanguinaria canadensis), whose blossoms only last for a day before they drop. Additionally frustrating is that cloud cover can hamper catching the full glory of the blooming of some species. You may show up on a sunny morning only to have the blossoms close up before your eyes. Species like spring beauties (Claytonia virginica) will only open in the full sun and will close again if clouds appear. This response to sunlight may be the result of temperature or light. Some ephemerals might provide longer viewing opportunities, since they hold their flowers for a longer period of time, or have many more plants that flower on different days.

Bloodroot (Sanguinaria canadensis)

Bloodroot (Sanguinaria canadensis)

Spring beauty (Claytonia virginica)

Spring beauty (Claytonia virginica) by Kaldari, via Wikimedia Commons

Most of the spring ephemerals are perennial. They have underground organs—bulbs, corymbs, etc.—that store nutrients to be used for producing leaves and flowers in succeeding year. White trout lilies (Erythronium albidum) are a good example. The trout lilies, both white and yellow species, derive one of their common names from the mottled leaves that some think resemble the markings on a trout. (Other common names include adder’s tongue and dog-toothed violet—the second name is curious because these are plants in the lily family, having no relationship to violets.)

Trout lilies also spread by underground rhizomes that form clumps, often covering large patches in the woodland, the mottled leaves camouflaging their abundance, only to become dazzling drifts of white when the sun appears. If you have  time, you can come out to the woodland early in the morning and watch the white petals of the trout lilies curl back and expose their yellow anthers to the sun—and pollinators.

There are also a few annual spring ephemerals. False mermaid (Floerkea proserpinacoides) is a spring ephemeral annual. Unlike many of the other ephemerals, false mermaid is inconspicuous in that it is a small, ferny green plant with tiny greenish flowers. Portions of the nature trail in the McDonald Woods are surrounded with acres of this species in spring. Even in these large numbers, without close inspection, it is difficult to tell when they are in flower. This species is dependent on its flowers producing one to three large seeds to be able to reproduce itself after the plant turns yellow and dies.

Many of the spring ephemerals depend on native bees for their pollination. 

The trout lilies are visited by an oligolectic bee (Andrena erythronii). “Oligolectic” means this is a bee that has a narrow, specialized pollen preference, typically for the pollen of a single genus of plants. The species name of this bee, erythronii, refers to the genus of the trout lily, Erythronium. Another ephemeral with an oligolectic bee pollinator is the spring beauty. The bee that is a specialist of this ephemeral, with its attractive pink-striped flowers, is Andreana erigeniae

Squirrel corn (Dicentra canadensis)

Squirrel corn (Dicentra canadensis) by Fritzflohrreynolds (Own work) [CC BY-SA 3.0], via Wikimedia Commons

While these plants often have specialist pollinators associated with them, they usually have several different pollinators that can visit, including other native bees and many species of flies.

For ephemerals in the genus Dicentra, such as Dutchman’s breeches and squirrel corn (Dicentra canadensis), queen bumblebees are an important pollinator. These ephemerals have tightly closed flowers, requiring significant strength to enter the flower and access the pollen and nectar. The large queen bumblebees are among the few pollinators equipped to gain access. This is not only important for the plants, it is also important for the bumblebees. Many native bees colonies die off in fall, leaving the queens to overwinter and start the new colonies in spring. These large, fuzzy bees are able to manufacture enough physiological heat, by vibrating their wing muscles and restricting their blood flow in the thorax, to get themselves flying early in spring before it’s warm enough for many other pollinators to go foraging for resources to start the new colonies. The spring ephemerals provide this important resource.

Besides being important sources of nectar and pollen for native insects, the spring ephemerals also serve the purpose of saving soil and reducing water runoff during a time of year when few other plants are growing.

Trout lilies, for example, have very efficient photosynthetic abilities and take advantage of the high light levels available in the spring woodland. This strong photosynthetic response requires large quantities of water to maintain the process. Therefore, abundant populations of this species and other ephemerals absorb large quantities of water that would otherwise move off site, often carrying valuable nutrients and soil with it. This high demand for moisture also causes the ephemerals to have shorter flowering periods in times of drought. In your yard, you can encourage ephemerals to flower longer during dry conditions by providing a little extra water. There is also some thought that the rapidly decomposing foliage of these “short-lived” plants provides readily available nutrients for other plants that begin growing later in the season.

One other fascinating thing about spring ephemerals is that essentially all of them rely on ants to disperse their seeds. This relationship is referred to as myrmecochory—”myrmex” being the Greek word for ant.

Each seed of the spring ephemerals has a structure called an elaiosome attached to its surface that attracts ants. The elaiosome is rich in lipids and proteins. The ants take the seeds back to their nests and consume the elaiosome as food, after which they bring the seed to the surface and deposit it on their trash piles, where the seeds tend to germinate in a rich, organic seedbed.

I include another plant with elaiosomes in the list of spring ephemerals. This is parasol sedge (Carex umbellata). This grass-like, early-flowering sedge produces most of its seeds very close to the soil surface, where ants are more likely to find them. It is not uncommon to find ants nesting at the base of these plants. I often get questions from people who have planted ephemerals in their yard, but say they don’t see seedlings, while their neighbors are finding them on their property. It is more than likely that the neighbors have the ant colony that is harvesting the seed and sowing them at the neighbors’.

Parasol sedge (Carex umbellata)

Parasol sedge (Carex umbellata)

Given that the spring ephemerals are adapted to growing in a cool, moist environment and highly dependent on early spring pollinators, climate change is likely to cause stress in the system. Early warming and possibly drought conditions in spring may disrupt pollinator interactions or shorten flowering periods, making seed production more difficult, or reducing the amount of time ephemerals have for storing nutrients for future flowering. 

False rue anemone (Isopyrum biternatum)

False rue anemone (Isopyrum biternatum)

With spring on the horizon, you should make plans to visit the McDonald Woods to view the diversity of colorful spring wildflowers. For those of you taking pictures, pay attention to weather forecasts, and be mindful of the potential to damage other vegetation while attempting to get the perfect shot.


©2018 Chicago Botanic Garden and my.chicagobotanic.org

Autumn Asters

Jacob Burns —  September 26, 2017 — 1 Comment

The harbinger of fall, for many folks, is when asters finally bloom. Their flowers look like miniature daisies and come in shades of purple, blue, white, and occasionally pink. These cool tones allow autumnal hues of yellow, orange, and red to truly pop throughout the landscape. Aster blossoms twinkle across roadsides, meadows, woodland edges, and even home gardens. Interestingly, astéri is the Greek word for star.

White wood aster (Eurybia divaricata)

White wood aster among birch trunks near the Bernice E. Lavin Plant Evaluation Garden sets the perfect fall scene.

Hosts of pollinators favor asters. The late-season blooms provide vital sustenance for adult monarch butterflies during their annual migration to Mexico. Each flower contains plentiful sources of pollen and nectar, because the central disc is comprised of up to 300 tiny florets. After pollination, a disc will turn darker and reddish, informing other insects to keep moving. In the end, birds come to consume the seeds.

Asters belong to a huge family called Asteraceae, which also includes daisies, black-eyed Susans, and sunflowers. They are mainly native to North America and Eurasia. More than 600 species once made up the genus known as Aster. However, in the 1990s, taxonomists decided to divide New World species into ten other genera. The most common ones are Eurybia and Symphyotrichum. Few nurseries adopt these names and continue to list their plants under the genus Aster

Asters are easy to please with well-drained soil and adequate sunlight. Some even prefer shade. An assortment of heights (1 – 6 feet tall) allows them to shine in the front, middle, or back of the border. Powdery mildew is problematic for some, but you can always hide the unsightly lower stems among grasses or ferns. While pretty in nature, some asters just look scruffy in the garden. Selecting the right type is the key to a tidy look. The following asters perform best:

Jindai Tatarian aster (Aster tataricus 'Jindai')

Jindai Tatarian aster (Aster tataricus ‘Jindai’) can be found in the Lakeside Garden and on Evening Island at the Trellis Bridge.

White wood aster (Eurybia divaricata)

White wood aster (Eurybia divaricata) can be found in the Heritage Garden beds, throughout the Landscape and Bulb Gardens, in large groupings on Evening Island, and all around the Plant Science Center.

Jindai Tatarian aster (Aster tataricus ‘Jindai’) originates in Asia and has uniquely large and toothed foliage. From mid- to late fall, lavender-blue daisies appear in showy flat-topped clusters upon 3 – 4 foot tall stems. Best planted in the back of a bed with plenty of sun and space, its roots slowly spread into a weed smothering ground cover. Pair it with some equally tall and tough switchgrass (Panicum virgatum).

White wood aster (Eurybia divaricata) blooms for a long time, starting in late summer and lasting throughout fall. Clouds of starry white flowers are borne on 2-foot stems with heart-shaped leaves. It grows in woodlands of eastern North America where it spreads slowly by rhizomes and quickly from seed. Cut spent flower stems off if you do not want extra plants. Combines wonderfully with ferns, sedges, and shade-loving goldenrods like Solidago caesia or Solidago flexicaulis.

Avondale blue wood aster (Symphyotrichum cordifolium 'Avondale')

Avondale blue wood aster (Symphyotrichum cordifolium ‘Avondale’) can be found on Evening Island, just west of the carillon along the path.

October Skies aromatic aster (Symphyotrichum oblongifolium 'October Skies')

Find aromatic aster (Symphyotrichum oblongifolium ‘October Skies’) in the Landscape Garden, along the Lakeside Garden path, at McGinley Pavilion, on Evening Island near the Arch Bridge, and near the Plant Science Center.

Avondale blue wood aster (Symphyotrichum cordifolium ‘Avondale’) is an extra-floriferous selection of an eastern North American species found at forest edges. A plethora of attractive blue flowers begin in early fall on 2 – 3 foot stems. Grows well in either sun or shade, where it adds additional color to perennials like Japanese anemone (Anemone hupehensis), monkshood (Aconitum), and the yellow fall foliage of blue star (Amsonia hubrichtii).

October Skies aromatic aster (Symphyotrichum oblongifolium ‘October Skies’) is a great alternative to New England aster (S. novae-angliae), because it is less prone to powdery mildew. With full sun, it forms a compact 2- x 2-foot mound of nicely scented foliage. In autumn, hundreds of blue-purple flowers cover the plant. The species naturally occurs across the central and eastern United States. Try it with fountain grass (Pennisetum alopecuroides).

Frost aster (Symphyotrichum pilosum)

Frost aster (Symphyotrichum pilosum) overflows the center plantings of the Heritage Garden.

Frost aster, or hairy aster (Symphyotrichum pilosum) is a 3- x 3-foot, clump-forming plant with many branched and arching stems. In fall, it becomes loaded with little white daisies and creates a baby’s breath appearance among flowers like Japanese anemone (Anemone hupehensis). Frost aster is common in a variety of dry, sunny habitats in eastern North America. It spreads happily by seed, so if you have too many, cut off the spent flower stems before they develop any further.


©2017 Chicago Botanic Garden and my.chicagobotanic.org

The fourth of July is upon us, and while many beautiful flowers can be found in patriotic shades of red and white, the color blue is very difficult to find at the Garden.

In fact, blue is a rare sight in the entire natural world. Less than ten percent of the plant kingdom features blue flowers, which is extraordinary, since pollinators don’t seem to have a problem with them. Scientists have been investigating the origins of blue flowers for a long time, and it was not until recently that they came up with a result.

Blue sea holly (Eryngium planum)

Blue sea holly (Eryngium planum)

Flower colors are based on pigments that include anthoxanthins and anthocyanins. Anthoxanthin colors contribute to yellow flower petals and are quite common in the plant world. Anthocyanin colors impart red, purple, and blue in blooms, but are found much less often in flora. For anthocyanin to steer blue, complex scenarios must occur. Most often, metal atoms and ions interact with the pigment to modify the color. In addition, they alter the pH of cellular fluids to be alkaline, while most organisms have an acid or neutral chemistry.

What is thought-provoking is that a red rose and a blue cornflower (Centurea cyanus) contain the same anthocyanin pigments. Cardinal flower (Lobelia cardinalis) and big blue lobelia (Lobelia siphilitica) are of the same genus, but one flower is red and the other is blue. It is the rare and complex modification of that pigment that contributes to the blue flower being blue. More surprising is that hybridizers have yet to develop a truly blue rose or carnation (without resorting to pigmenting water, which a plant takes up, changing the color of its bloom). 

Royal Aspirations larkspur (Delphinium elatum 'Royal Aspirations')

Royal aspirations larkspur (Delphinium elatum ‘Royal Aspirations’)

Lobelia (Lobelia erinus)

Lobelia (Lobelia erinus)

Pacific Giant Cameliard larkspur (Delphinium 'Cameliard')

Pacific Giant™ cameliard larkspur (Delphinium ‘Cameliard’)

Since blue is uncommon, visitors at the Garden should take extra time to enjoy the flowers in the English Walled Garden, where they will find containers full of adorable Felicia daisy (Felicia heterophylla ‘Forever Blue’) right beside sky-colored plants called southern star (Tweedia caerulea ‘Heaven Born’)—a member of the milkweed family. In addition, there are cool-hued drifts of Magadi™ electric blue lobelia (Lobelia erinus ‘KLELE10670’) weaving throughout several garden beds, as well as spilling out of containers.

Another area with a good deal of blue flowers is the Heritage Garden. In the plant family area, you will find intricate love-in-a-mist (Nigella damascena ‘Miss Jekyll’) blossoms mingling with wispy yet showy Siberian larkspur (Delphinium grandiflorum ‘Blue Butterfly’). And nearby, nile lily flowers (Agapanthus ‘Queen Anne’) explode like bright blue fireworks. And finally, in the geographic area, sea holly (Eryngium planum) creates a shiny and spiky blue accent.

(Agapanthus africanus 'Queen Anne')

Nile or African lily (Agapanthus africanus ‘Queen Anne’)

Love-in-a-Mist (Nigella damascena 'Miss Jekyll')

Love-in-a-mist (Nigella damascena ‘Miss Jekyll’)

Blue Butterfly larkspur (Delphinium grandiflorum 'Blue Butterfly')

Blue Butterfly larkspur (Delphinium grandiflorum ‘Blue Butterfly’)

While it is difficult to achieve blue pigments in plants, the ones that did are certainly successful in this world. The word “perseverance” comes to mind, which just so happens to be what the blue within the American flag represents. Anyone who has marveled at a field of Texas bluebonnets (Lupinus texensis) and witnessed the huge number of bees and butterflies working to gather its pollen would agree.

Southern star (Tweedia caerulea 'Heaven Born')

Southern star (Tweedia caerulea ‘Heaven Born’)

Flying Saucers morning glory (Ipomoea tricolor 'Flying Saucers')

Flying saucers morning glory (Ipomoea tricolor ‘Flying Saucers’)

Happy Fourth of July everyone!


©2017 Chicago Botanic Garden and my.chicagobotanic.org

Wolfsbane is a beautiful—and poisonous—fall-blooming perennial. It also has a colorful history associated with werewolves, vampires, and witches.

PHOTO: Werewolf gargoyle at the Cathédrale Notre-Dame de Moulins

Werewolf gargoyle at the Cathédrale Notre-Dame de Moulins

The plant has been a familiar plot element in horror movies, television shows, and novels. In the Harry Potter series, Remus Lupin, a tormented werewolf, drinks a potion of wolfsbane carefully concocted to control his transformations. As early as Dracula in 1931, wolfsbane casually replaced garlic as a repellent for vampires in film. Nevertheless, the correlation of wolfsbane with the supernatural predates Hollywood and familiar authors. 

In Greek myth, wolfsbane (Aconitum) originated from the toxic slobber of a three-headed dog named Cerberus, the scary canine guardian to the gates of Hell. In the Dark Ages, wolfsbane was said to be used by witches in spells and potions and was one of several ingredients for an ointment that, when applied to a broom, could facilitate flight. Stories also proclaimed that a sorceress who carried wolfsbane seeds wrapped in lizard skin could become invisible and witches who applied the poisonous sap to their flints and launched them at unsuspecting enemies.

One thing both Hollywood and horticulturists can agree on: wolfsbane is a potent plant. Ingesting wolfsbane is typically fatal. 

PHOTO: Arends azure monkshood/wolfsbane.

Arends azure monkshood (Aconitum carmichaelii ‘Arendsii’)

PHOTO: Lamarck monkshood/wolfsbane.

Lamarck monkshood (Aconitum lamarckii)

The plant belongs to a genus of highly poisonous perennials known as monkshood or aconite. They naturally grow in mountainous areas across the northern half of the globe and are also planted in gardens for their deep purple blooms, which continue flowering long after other perennials fade for the season. Ancient Greeks hunted wolves by poisoning their bait with this plant, which lead to the common name of wolfsbane.

PHOTO: Werewolf illustration circa 1512 by Lucas Cranach the Elder

Werewolf illustration circa 1512 by Lucas Cranach the Elder

While those hunting traditions were lost, the plant retained its common name into the Middle Ages, where wolves and werewolves were a genuine fear in Europe. Frightened folks turned to growing wolfsbane for their protection, as superstitions said that werewolves could be repelled by the plant, or even tamed by it. Others, however, believed that having contact with wolfsbane on a full moon could actually cause shape-shifting. Patients who suffered from lycanthropy (the delusion of being a wolf) were prescribed regular—and often lethal—doses of wolfsbane by their medieval doctors.

For gardeners, it is important to remember to always wear gloves while handling a deadly plant such as wolfsbane.

Find wolfsbane at the Garden with our Plantfinder or on the GardenGuide app. Remember to look—don’t touch!—its beautiful blooms. Happy Halloween!


©2016 Chicago Botanic Garden and my.chicagobotanic.org

Each fall, we sing the praises of fall allium and autumn crocus blooms. This year, however, a special mention must be made for the glorious gladiolus! Especially the delicate, 4-inch salmon pink flowers of the salmon gladiolus (Gladiolus oppositiflorus spp. salmoneus).

Hailing from the summer rainfall areas of the cold, higher elevations of the Drakensberg Mountains of South Africa, this beautiful wild species has proven amazingly hardy in the Chicago Botanic Garden’s Graham Bulb Garden over the last five years—including a couple of winters with record-setting cold temperatures!

PHOTO: Gladiolus oppositiflorus ssp. salmoneus.

Gladiolus oppositiflorus ssp. salmoneus produces elegant, upright flower stalks that do not require staking!

Two characteristics of its native habitat nominated the gladiolus for trial at the Garden: first, it is a winter-growing bulb in South Africa, which translates to summer growth in North America. Second, this plant thrives in moist soils in grassy areas—it was perfect for the site we chose in the Bulb Garden.

Based upon its initial success in our plant trial program, other gladiolus (also currently in full flower) were added to the trials. We’ve also discovered that these wild species thrive and multiply in well-drained soils (but do not tolerate flooded soils). The beautiful, red-flowered Gladiolus saundersii is also native to the Drakensbergs, but from a higher, colder, and snowier habitat. And a third selection is probably a close relative of Gladiolus dalenii var. primulinus. Discovered in an old, abandoned farmstead in North Carolina, and sold under the name ‘Carolina Primrose’, this gladiolus generally blooms in July and early August (although it is still blooming now). All have come through the record-breaking cold of the last couple of winters. 

Gladiolus is the largest genus in the Iridaceae (iris plant family) with 255 species worldwide; 166 of them in southern Africa. The genus was given its name by Pliny the Elder, in reference to the size and shape of the leaves, which are similar in shape and size to a short sword favored by Roman-era gladiators: the gladius.

It’s not easy to find commercial sources for these bulbs, but it’s well worth the effort to obtain an elegant, refined, fall-flowering, and hardy gladiolus.


©2015 Chicago Botanic Garden and my.chicagobotanic.org