Archives For what’s in bloom

Escape to a warmer climate and enjoy a mini-vacation from Chicago winters in the Greenhouses at the Chicago Botanic Garden. Boyce Tankersley, director of living plant documentation, showed us some of the more unusual plants we will find flowering—or fruiting—in the Greenhouses in January.

Click here to view the video on YouTube.

Discover amazing aloes and euphorbias in the Arid Greenhouse:

  • We have 43 different species of aloes, including: dwala aloe (Aloe chabaudii), hidden foot aloe (Aloe cryptopoda), and bitter aloe (Aloe ferox). The long tubular flowers of aloes are adapted for pollination by sunbirds, the African equivalent of our hummingbirds. The sap of aloe vera is used widely in cosmetics and to treat burns.
  • Our 35 different species of euphorbias are also spectacular during this time period. Look for geographic forms and cultivars of Euphorbia milii as well as the spectacular Masai spurge (Euphorbia neococcinea). Did you know that poinsettias are also in the genus Euphorbia?
  • About to flower for only the second time in 30 years is turquoise puya (Puya alpestris), a bromeliad native to the high, dry deserts of Chile whose turquoise flowers are irresistible to hummingbirds.

PHOTO: Bitter aloe (Aloe ferox).

Bitter aloe (Aloe ferox)

PHOTO: Crown-of-thorns (Euphorbia milii).

Crown-of-thorns (Euphorbia milii)

PHOTO: Turquoise puya (Puya alpestris).

Turquoise puya (Puya alpestris)

The Semitropical Greenhouse is where you will find the following:

  • Paper flower—What appears to be the “flowers” of Bougainvillea ‘Barbara Karst’ and ‘Singapore White’ are actually colorful bracts surrounding the small, white flowers.
  • Dwarf pomegranate (Punica granatum ‘Nana’)—Pomegranates are native to the Middle East and are part of the Biblical Plants collection in the Semitropical Greenhouse.
  • Calamondin orange (× Citrofortunella mitis)—This decorative, small orange is too bitter to be eaten.
  • Ponderosa lemon (Citrus × ponderosa)—Ponderosa lemons are the largest in the world.
PHOTO: Bougainvillea × buttiana 'Barbara Karst'.

Paper flower (Bougainvillea × buttiana ‘Barbara Karst’)

PHOTO: Dwarf pomegranate (Punica granatum 'Nana').

Dwarf pomegranate (Punica granatum ‘Nana’)

PHOTO: Calamondin orange (x Citrofortunella microcarpa).

Calamondin orange (× Citrofortunella microcarpa)

PHOTO: Ponderosa lemon (Citrus x ponderosa).

Ponderosa lemon (Citrus × ponderosa)

Don’t miss these highlights in the Tropical Greenhouse:

  • “Alice” the titan arum (Amorphophallus titanum) with her magnificent orange fruiting spike. (The fruiting stage does not produce an odor.) The fruits will mature over the next two months to a deep red. In the wilds of Sumatra, ripe fruits are eaten by the rhinocerous hornbill, which spread the seeds.
  • The vining Vanilla planifolia var. variegata is a variegated form of the Central American orchid that produces vanilla beans
  • Cacao (Theobroma cacao)—the pods from this plant are used to make chocolate.  
  • Nodding clerodendrum (Clerodendrum nutans) is among the first of this genus of winter-flowering shrubs and vines to be covered in showy flowers.
  • The elegant white Angraecum Memoria Mark Aldridge orchids with their long nectar tubes signal the start of orchid flowering season.
PHOTO: Vanilla orchid (Vanilla planifolia).

Vanilla orchid (Vanilla planifolia)

PHOTO: Cocoa pod (Theobroma cacao).

Cocoa pod (Theobroma cacao)

PHOTO: Nodding clerodendrum (Clerodendrum nutans).

Nodding clerodendrum (Clerodendrum nutans)

PHOTO: Angraecum Memoria Mark Aldridge.

Angraecum Memoria Mark Aldridge (A. sesquipedale × A. eburneum ssp. Superbum)

Please note: The Greenhouses and adjacent galleries will have limited access January 25 – February 7; from February 8 – 12, they will be closed in preparation for the Orchid Show, opening February 13, 2016. From February 13 – March 13, the Greenhouses will be open to Orchid Show ticketed visitors only. 


©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

“Titan Tim” Pollak here, with today’s update on Spike, our first-ever corpse flower.

PHOTO: The corm of an Amorphophallus titanum: after a dozen or so years, it's large enough to produce a bloom!

The corm of an Amorphophallus titanum: after a dozen or so years, it’s large enough to produce a bloom!

Spike just keeps on growing at the Semitropical Greenhouse, and visitors are loving it. As they learn more about the coming bloom from the docents posted there, one of the most frequently ask questions is, “How could you tell this time that Spike was a flower?”

How could we tell that Spike was going to be a flower? It’s tricky. Even the most experienced botanists have a hard time determining whether a titan arum shoot is a flower or a leaf at first. But soon enough, the clues start to add up.

PHOTO: An Amorphophallus titanum shoot to the right of a leaf stalk provides comparison for determining the slight bulge which could mean a flower bud.

An Amorphophallus titanum shoot to the right of a leaf stalk provides comparison for determining the slight bulge, which could mean a flower bud.

PHOTO: The emerging Amorphophallus titanum plant looks leafy, unlike the smooth spadix which emerges from a flower bud.

The emerging Amorphophallus titanum plant looks leafy, unlike the smooth spadix that emerges from a flower bud.

  1. Spike is 12 years old. We know from other botanic gardens and conservatories that titan arums take a decade or more to send up their first flower shoot. We’ve been tending to this corm for about 12 years, so the timing was right.
  2. Is the corm big enough? The smaller the corm, the less power it has stored to send up the titan’s huge flower. This corm is about the size of a beach ball—definitely an appropriate size for flowering.
  3. A bulge at the base. It’s subtle, but a slight swelling at the base of the newly emerged shoot signaled something different than a leaf.
  4. A little off center. At 18 to 20 inches tall, we noticed a telltale sign: the tip of the shoot was off-center. While leaf shoots are true to center, we knew that a flower shoot powers up in a slightly different way. Again: it’s subtle but telling!
  5. Horticultural intuition. Both Deb Moore—our indoor floriculturist who tends to our nine titan arums—and I felt that the overall look of the shoot was different than what we’d experienced before with shoots that become a leaf. (While the titan’s non-bloom form may look like a stalk with multiple leaves, it is actually a single, giant leaf!) Like every gardener, you develop a sense for what’s “normal” and what’s not when it comes to your plants. We both thought that this shoot was somehow different, and it was!

PHOTO: While these may look like branches and leaves, each of these Amorphophallus titanum are actually single-leaf plants.

While these may look like branches and leaves, each of these Amorphophallus titanum are actually single-leaf plants.

Our final “sign” was to ask the experienced titan growers from other institutions. We called upon the folks at the Huntington Library, Art Collections, and Botanical Gardens in San Marino, California; Smithsonian Gardens in Washington, D.C.; Phipps Conservatory and Botanical Gardens in Pittsburgh, Pennsylvania; and Missouri Botanical Garden in St. Louis, Missouri, for their opinions and expertise. Their final confirmations gave us the thumbs up to go public with the big news that Spike would soon blast into bloom!

Like first-time parents, we are learning as we go. I can’t tell you how excited we all are in the production greenhouses—it’s a thrill to watch a plant that you’ve tended for so long finally get ready to flower! Visitors’ anticipation is rubbing off on us, too—we’ll be standing right next to you as the titan arum heads into its big night of bloom!

I’ll keep you posted…


©2015 Chicago Botanic Garden and my.chicagobotanic.org

Is Spike Blooming Yet?

3 Ways to Tell

Tim Pollak —  August 11, 2015 — 15 Comments

Spike is about halfway up the expected height chart (we’re thinking 6 to 7 feet, ultimately), so the big question now is, “How do you know when it’s going to bloom?”

PHOTO: Taken yesterday (August 11, 2015), our titan arum reaches the "halfway" point in its growth chart.

Taken yesterday (August 11, 2015), our titan arum reaches the “halfway” point in its growth chart.

Titan arums don’t give up their secrets easily. Just as it’s difficult to distinguish a leaf bud from a flower bud (we talked about that in our last blog post), it’s hard to know when the bloom cycle has actually begun.

Once again, our titan-experienced friends at other botanic gardens and conservatories have offered up a few helpful hints.

PHOTO: Closeup of spathe loosening from spadix of Amorphophallus titanum at the Sydney Royal Botanic Gardens 2 days before opening (in 2008).

A close-up shows the spathe loosening from spadix of Amorphophallus titanum at the Sydney Royal Botanic Garden two days before opening (in 2008).

  1. Growth slows. Spike is powering up 4 to 6 inches per day. As a titan gets ready to open, that growth rate slows noticeably. It’s a rather obvious clue, but by the time the plant is 6 or 7 feet tall, you start to marvel at the overall size and forget about incremental daily growth. We’re posting our measurements daily here, so heads up when you notice the numbers getting smaller.
  2. Bracts fall. What? Look down at the base of the spathe. Two modified leaves called bracts encircle the spathe. As Spike gets taller, these protective bracts shrivel and dry up. About a day before full bloom, they fall off—first one, then the other. That’s a sure sign that bloom is about to happen.
  3. The spathe loosens. Tightly wound around the towering spadix as it shoots up, the frilly leaf called a spathe starts to loosen its grip as bloom time nears, revealing the crazy-beautiful maroon color inside.

So those are the clues we’re watching for—now you can watch for them, too! How long will it be before the big night? I’ll keep you posted…


©2015 Chicago Botanic Garden and my.chicagobotanic.org

What’s that smell?

Tim Pollak —  August 6, 2015 — 6 Comments

In gardening, as in life, patience is a virtue. Twelve years ago, the Garden embarked on a mission to bring a rock star of the plant world to the Chicago Botanic Garden. The titan arum (Amorphophallus titanum), also known as the corpse flower, is the largest flowering structure in the world. When it blooms, it puts on a show like no other. 

Huge. Rotten. Rare. Watch our video on YouTube of Spike moving to his display location.

Why the big stink? During the peak of its bloom, which could happen in the next two weeks, the titan arum will emit a foul odor that pollinators can detect from about an acre away. Who would want to miss that?

PHOTO: Checking in on the progress of the titan arum, or corpse flower (Amorphophallus titanum).

Checking in on the progress of the titan arum, or corpse flower (Amorphophallus titanum)

Native to the rainforests of western Sumatra, Indonesia, the titan arum is distinguished by its large size, odd shape, and terrible stench (hence its common name, corpse flower). Plants bloom for a single day every seven to ten years, and it is nearly impossible to predict the day it will be at the peak of bloom. When those magical hours finally occur, the bloom unfurls into a dramatic, blood red “flower” with a nauseating stench that can be detected up to an acre away. It’s a once-in-a-lifetime experience. 

We have been cultivating eight of these mysterious plants behind the scenes in the production greenhouses, watching them grow foliage each year, and guessing what a flower might look like as it emerges.

Today we are so excited to be moving Spike to the Semitropical Greenhouse in the Regenstein Center. (We have named our titan arum Spike because when you grow a plant for 12 years, you start to think of it as a child.) Spike is growing several inches every day. We are so proud of Spike and are also thrilled he is the first titan arum to bloom in the Chicago area.

Come welcome Spike, and join the countdown to the big bloom! If you do, let us know what you think in comments here, via Twitter, Instagram, Facebook or Tumblr. Use the hashtag #CBGSpike and our handle @chicagobotanic


©2015 Chicago Botanic Garden and my.chicagobotanic.org