PHOTO: Outdoor floriculturist Tim Pollak talks titan arum with Garden visitors.

Is Spike Blooming Yet?

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

Published by

Tim Pollak

"Titan" Tim Pollak is outdoor floriculturist for the Chicago Botanic Garden. He earned his BS degree from Colorado State University in Landscape Management and Nursery and Greenhouse Management.

15 thoughts on “Is Spike Blooming Yet?”

  1. How very cool to experience something so astounding after years of care. Can’t wait to experience it!!

    1. Thanks Don. We can’t wait either for the big bloom event. Come out to the Garden to see open 9pm-2am !!!!

  2. Thanks Don. Yes we all are very excited about Spike, and can’t wait for the big bloom and rotten smell. Very proud to give the our visitors this opportunity to see it up close and for the first time in Chicago area. It is one the many “wows” we have underway. Much more to come…. Tim Pollak

    1. Hi Tim, we live in Fort Wayne, Indiana. We went to the garden on Saturday and are planning to go there again we it blooms. I was wondering, will you post the news as soon as it starts to bloom? Do you have an estimated time frame of it? Because the latest the post I can see is on Aug.11. Thanks.

      1. Bin, yes will be using and blasting out on all the sources of social media available 2 days prior to determining Spike is going to bloom. As well on our website, you can sign up for free ENewsletter up keep in the loop on his status. And quite sure the print and television media will be all over it as well. Very exciting for all of us!

    1. Charles. We have a time lapse camera on Spike since we moved him on display. As the big bloom day approaches we will be posting details and expected date of bloom and video of the event.

  3. I wonder who the first person was that figured out this unusual plant bloomed at such a long interval. With the bloom only lasting about 36 hours, it may have been totally coincidental. I also wonder if the material from the plant is used for anything – medical, practical, etc. – or not. It’s fascinating. Thank you for bringing this to Chicago!

    1. Chicago Catt, one of the issues with this plant dying out in the wild is that it’s corm is huge (meant literally) food source.

  4. why is this thing so late!! Shouldn’t it have bloomed by now? Are you guys giving Spike enough pollinators?

    1. Hi, Marjorie!

      There’s a range of time it takes for a corpse flower to bloom. In recent history, we can find data from one botanic garden that their titan arum bloomed 24 days after the bud was visible, but another garden’s bloom took 34 days for the same-sized plant to flower. It’s a waiting game for horticulturists (and fans!) everywhere.

      One he opens up, Spike is going to be hand-pollinated by one of our scientists with pollen we’ve received from 2 other botanical gardens, not by his native pollinators. The timing of the pollination is key, so we already have the pollen on hand, waiting for the right moment.

      1. ah!! Got it! The anticipation is killing me in the meantime! I am going to be one of those people showing up at 2 am, I was watching the webcam online at 2 am to check on him!

  5. Tim,
    I’m so glad you decided to give Spike a night off tonight. I was worried that Spike has been ‘disturbed’ by the 24 hour light with no dark cycle as would be the norm in nature. What is Spike’s current temperature? You mentioned that it will rise to 90 – 98 degrees before it blooms.
    Thank you for allowing us to experience this incredible plant!

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