The Power of Plants: Botanical Weightlifters

There are things I look forward to seeing every season.

In spring, I watch for “mighty plants” that emerge from the ground with enough force to heave the soil above ground. These botanical weightlifters—the bulbs, grasses, and other emergent plants—pushing up soil that was compressed by a blanket of snow never fail to impress me. I am in awe of the strength of plants. 

PHOTO: Daffodil leaves have pushed through the mulch, lifting it off the ground.
Daffodil leaves erupted from the ground in March and lifted the mulch in the beds around the Regenstein Learning Campus.

Seeing bulbs coming up all around me inspires lots of questions. I want to understand how this is possible and I want to test their strength. So I spent a few weeks playing around with this phenomenon in the Learning Center’s Boeing Nature Laboratory. 

To begin, I wanted to demonstrate that seeds will lift soil in a pot. I soaked bunch of wheat seeds overnight and planted them in a pot. I covered them with a generous amount of potting soil (about a 1/2-inch layer) and I tamped the soil down gently so that it would be compressed—like the topsoil might be after a winter of snow cover. Three days later, I had results! I sprayed the soil disk to give it a little adhesion, so I could see how long it would hold together as the grass lifted it up.

PHOTO: A few days after planting the soaked wheat seeds, they are already sprouting and pushing up the soil.
Day 3 after planting the seeds: They are pushing up the compressed layer of soil.
PHOTO: The wheat leaves have grown to an inch over the pot and are holding up a disk of soil.
Day 4: The leaves have pushed the soil up a little more.
PHOTO: The wheat is 2-3 inches above the pot and still suspending the disk of soil.
Day 5: The soil is light and there are a lot of wheat plants, so they continue to lift the soil.
PHOTO: The grass is now 4-5 inches tall and the disk of soil is on top, but leaning to the side, about to fall off.
Day 6: “Get off me, Soil! – Umph!”
PHOTO: The disk of soil that was lifted by the grass has fallen to the side of the pot.
Day 7: Phew!

That was so much fun, I tried the same thing with a bunch of bean seeds.

PHOTO: the top of the soil is rising about a half inch out of the pot.
Bean sprouts pushing…
PHOTO: the sprouting beans can be seen pushing up the top of the soil, now 1-2 inches over the top of the pot.
…pushing…
PHOTO: a dozen bean plants are growing out of the pot and pushing the top soil disk to the side.
…and bursting from inside the pot.

This demonstration was pretty easy and impressive. It is a simple activity to illustrate how plants and other living things change their environment to suit their needs (which is a disciplinary core idea in Next Generation Science Standards for kindergarten). I recommend doing it in the classroom or at home, just for fun.

This is just the beginning. I will be sharing the results in a future blog post. But before I do, I would like to make a few points about the nature of science and how scientists work. 

  1. Science is a collection of established facts and ideas about the world, gathered over hundreds of years. It is also the process by which these facts are learned. Science is both “knowing” and “doing.”
  2. Discoveries start when you watch nature and ask questions, as I did in watching spring bulbs come up. Before beginning an experiment, scientists play. They mess around with materials and concoct crazy ideas. They are constantly asking, “I wonder what will happen if I do ___ ?” That is when discoveries actually happen.
  3. Scientists do formal experiments with purpose, hypothesis, procedures, results, and conclusions after they think they have made a discovery. They use the experiment to test their discovery and provide convincing evidence to support it. In some cases, the experiment disproves a fact or idea, which is a different kind of new understanding about the world. 

I have to agree with Boyce Tankersley, the Garden’s director of Living Plant Documentation, who recently wrote “The SciFi Rant.” Those of us who lean toward botany instead of horticulture are more interested in growing plants to yield ideas rather than meals. In my continuing investigation, I have two goals, and neither is to produce anything to eat.

First, I want to determine the strength of sprouting seeds and see how far I can push them. For example, how many bean sprouts will it take to lift a coconut? I want to find a standard way to measure seed strength.

Second, I want to establish a reliable method for experimenting with seed strength so teachers and students can replicate the procedure, modify it as needed, and use it for their own investigations without going through the awkward phase of figuring out the best way to do this.

PHOTO: a 6 inch square pot is topped with a round plastic lid and a coconut.
Will the mighty beans sprouting under this menacing coconut have the power to lift it off the top edge of a pot? Stay tuned…

I invite you on my journey.
(To be continued.)


©2018 Chicago Botanic Garden and my.chicagobotanic.org

Save the Earth, Watch Dandelions Grow

I am often asked, “What can kids do to help the Earth?”

There is a standard litany of “Reduce, Reuse, Recycle” suggestions that almost everyone can tell you: recycle your garbage, turn the lights off when you leave a room, turn the water off while brushing your teeth, and so forth. 

EarthWe’ve been saying these same things for decades. And while they’re great ideas, they’re things we should all be doing. It’s time to give kids a chance to do something bigger. During Climate Week this year, I am offering a different suggestion: Watch dandelions grow and participate in Project BudBurst.

PHOTO: Dandelions.
These happy dandelions could contribute valuable information to the science of climate change.

Project BudBurst is a citizen science program in which ordinary people (including kids 10 years old and up) contribute information about plant bloom times to a national database online. The extensive list of plants that kids can watch includes the common dandelion, which any 10-year-old can find and watch over time.

Why is this an important action project?

Scientists are monitoring plants as a way to detect and measure changes in the climate. Recording bloom times of dandelions and other plants over time across the country enables them to compare how plants are growing in different places at different times and in different years. These scientists can’t be everywhere watching every plant all the time, so your observations may be critical in helping them understand the effects of climate change on plants.

What to Do:

1. Open the Project Budburst website at budburst.org and register as a member. It’s free and easy. Click around the website and read the information that interests you.

2. Go to the “Observing Plants” tab and print a Wildflower Regular Report form. Use this form to gather and record information about your dandelion. 

3. Find a dandelion in your neighborhood, preferably one growing in a protected area, not likely to be mowed down or treated with weed killers, because you will want to watch this plant all year. It’s also best if you can learn to recognize it without any flowers, and that you start with a plant that has not bloomed yet.

4. Fill in the Wildflower Regular Report with information about the dandelion and its habitat.

Common Plant Name: Common dandelion

Scientific Name: Taraxacum officinale

Site Name: Give the area a name like “Green Family Backyard” or “Smart Elementary School Playground”

Latitude and Longitude: Use a GPS device to find the exact location of your dandelion. (Smartphones have free apps that can do this. Ask an adult for help if you need it.) Record the letters, numbers, and symbols exactly as shown on the GPS device. This is important because it will enable the website database to put your plant on a national map.

Answer the questions about the area around your plant. If you don’t understand a question, ask an adult to help you.

PHOTO: This is a printout from the Project BudBurst Website, that asks about the location of the plant and provides places to record bloom times, as well as other comments.
The BudBurst Wildflower Regular Report is easy to use and will guide you through the process.
girl with data sheet
After you find a dandelion you want to watch, record information about the location of the plant.

5. Now you’re ready to watch your dandelion. Visit it every day that you can. On the right side of the form, record information as you observe it.

budburst notebook

  • In the “First Flower” box, write the date you see the very first, fully open yellow flower on your dandelion.
  • As the plant grows more flowers, record the date when it has three or more fully open flowers.
  • Where it says “First Ripe Fruit,” it means the first time a fluffy, white ball of seeds is open. Resist the temptation to pick it and blow it. Remember, you are doing science for the planet now!
  • For “Full Fruiting” record the date when there are three seedheads on this plant. It’s all right if the seeds have blown away. It may have new flowers at the same time.
  • In the space at the bottom, you can write comments about things you notice. For example, you may see an insect on the flower, or notice how many days the puffball of seeds lasts. This is optional.
  • Keep watching, and record the date that the plant looks like it is all finished for the year—no more flowers or puffballs, and the leaves look dead.
  • When your plant has completed its life cycle, or it is covered in snow, log onto the BudBurst website and follow directions to add your information to the database.


Other Plants to Watch

You don’t have to watch dandelions. You can watch any of the other plants on the list, such as sunflower (Helianthus annuus) or Virginia bluebell (Mertensia virginica). You can also watch a tree or grass—but you will need to use a different form to record the information. Apple (Malus pumila), red maple (Acer rubrum), and eastern white pine (Pinus strobus) trees are easy to identify and interesting to watch. If you are an over-achiever, you can observe the butterfly milkweed (Asclepias tuberosa) bloom times and do citizen science research for monarchs at the same time! (The USDA Forest Service website provides information about that; click here for more information.) 

PHOTO: Two girls are looking closely at a milkweed plant that has about eight green seed pods.
These students are observing a milkweed that is in the “First Ripe Fruit” stage.

For the past two springs, educators at the Chicago Botanic Garden have taught the fifth graders at Highcrest Middle School in nearby Wilmette how to do Project BudBurst in their school’s Prairie Garden. The students are now watching spiderwort, red columbine, yellow coneflower, and other native plants grow at their school. Some of these prairie plants may be more difficult to identify, but they provide even more valuable information about climate.

So while you are spending less time in the shower and you’re riding your bike instead of asking mom for a ride to your friend’s house, go watch some plants and help save the planet even more!


©2015 Chicago Botanic Garden and my.chicagobotanic.org

Growing a Bean in a Bag

Garden blog followers may remember that in “How to Train Your Plant” I demonstrated a way to grow a bean seed in a plastic bag to test geotropism. I started working on that project around Thanksgiving week last year. At that time, I started a few bean bags just to see what would happen. I kept one seed growing in the bag all winter, adding water as needed.

PHOTO: A ziptop bag was used as a container to grow a bean plant. Roots, stem, leaves, and the remains of the original seed are visible.
The bean plant grew for five months, leaning toward the window in my office.

The plant produced a white flower about a month ago. I should have taken a picture. Now this week I discovered a seedpod growing where the flower had been! In the picture, you can see the wilted flower petals still hanging from the tip of the reddish colored pod. Botanically speaking, this is the fruit of the plant, even though you might not think of beans as fruit in your diet.

PHOTO: a red bean pod, about 2 and a half inches long is attached to the stem of the plant.
The red fruit was hidden under the leaves.

So if you try this activity, and you stick with it for six months, you, too, may be rewarded with a little treasure!


©2013 Chicago Botanic Garden and my.chicagobotanic.org

Is spring as late as we think?

This year, it sure felt like spring was a long time coming — especially compared to last year when it seemed that we went straight into summer! I wonder how the wildflower timing of spring compared to previous years in the Chicago area…

Mayapples, April 25, 2012
Mayapples, April 25, 2012
Mayapples, May 2, 2013
Mayapples, May 2, 2013

For several years now, I’ve been working on a web-based citizen scientist project, called Project BudBurst, with colleagues at the National Ecological Observatory Network (NEON). We study the phenology — the timing of natural events like blooming, fruiting, and leaf fall — of plants around the country. Our participants track when plants bloom in their area, and we compare the reports to records from other parts of the country.

You can help us collect data! Sign up to help at Project BudBurst.

For instance, I’ve been tracking when the first forsythia flower opens on the plants near the Garden’s front gate since 2007. The earliest bloom I have on record in that time was last year, on March 15, 2012. The latest first flower for this specimen was this year, on April 20, 2013. In 2007 and 2008, however, we also had first flowers in mid-April (April 16, 2007, and April 17, 2008, respectively). So, as we look back in time, this year’s bloom time doesn’t feel quite so late. In the graph below we show the variation in flowering dates (using Julian dates, which standardize for differences in dates between nonleap and leap years).

forsythia data

In the Chicago area, we have a wealth of phenology data collected by the authors of our local flora, Plants of the Chicago Region by Swink and Wilhelm (1994). While they were gathering data for their book, they recorded when they saw plants in bloom from the late 1950s to the early 1990s. They record the forsythia bloom period as April 25 to May 5. So, when we look still further back in time, our “late” spring is much earlier than it has been in the past.

I took a similar look at several other species, both native and nonnative, for which we have both Project BudBurst data and data from Swink and Wilhelm’s book. About 70 percent of the species have earlier flowering dates in the last six years compared to those recorded by Swink and Wilhelm. Some of the species that have advanced their flowering dates are in the table below.

Species Earliest First Flower Observations
Common name
Genus species
Swink & Wilhelm
1950s – 1990s
Project BudBurst
2007 – 2012
Days
Advanced
Forsythia
Forsythia x intermedia
April 25 March 15 -40
Spiderwort
Tradescantia ohiensis
May 14 April 12 -32
Dogtooth violet
Erythronium americanum
April 6 March 20 -17
Red Maple
Acer rubrum
March 20 March 6 -14
Mayapple
Podophyllum peltatum
May 1 April 17 -13
Lilac
Syringa vulgaris
May 3 March 20 -44
Black locust
Robinia pseudoacacia
May 9 April 20 -19
Bradford pear
Pyrus calleryana
April 15 April 13 -2

Plant phenology, particularly when plants leaf out and bloom in the spring, is remarkably sensitive to the annual weather. Looking at phenological records over much longer periods of time can tell us a lot about how the climate is changing. Many scientists are comparing contemporary bloom times with historic bloom times recorded by naturalists like Aldo Leopold in the early 1900s, and Henry David Thoreau in the mid 1800s, as well as records kept by farmers, gardeners, and others interested in the natural world. Two of the longest phenological data sets are those maintained for cherry blossoms in Japan (dating back to 900 AD) and for grape harvest dates by winemakers in Switzerland (dating back to 1480 AD).

Plants have so much to tell us, if we take the time to listen!


©2013 Chicago Botanic Garden and my.chicagobotanic.org

How to Train Your Plant II

Blog followers will remember that in the first “How to Train Your Plant” post, we demonstrated how plants respond to the gravitational pull of the earth. Geotropism is difficult to overcome, but that didn’t stop me from trying to make a plant grow sideways through a maze. You can try this activity at home.

You will need these items:

  • a shoebox (or any kind of box)
  • cardboard to make dividers
  • duct tape (or any opaque tape)
  • soaked bean seeds—I used different beans from a soup mix
  • a container with soil
PHOTO: The materials for the maze are displayed.
You’ll need a shoe box, cardboard dividers, seeds, a pot with soil medium, and of course scissors and tape for constructing the maze.

Stand the box on its side. Then cut two pieces of cardboard to fit in the box and make divisions. You’ll want these to fit as snugly as possible inside the box, but they don’t have to be perfect. The tape will fix that. Cut a large window in each divider. Cut a window on one end of the box. Tape the dividers in place as shown in the picture.

PHOTO: The maze assembly is shown in the shoebox. There are two dividers with cut out windows and a whole in the side of the box for light to shine sideways on the sprouting bean seeds.
Pardon the crude appearance of this maze. I wasn’t going for style points.

Plant the seeds in the soil and put the container on the side opposite of the hole you cut. Just for fun, I used several different seeds from a bean soup mix to see if one kind would get through the maze better than the others. It was like a bean-seed “race.” You can try whatever you like.

Make sure the holes in the divisions are big enough to allow lots of light in from the side, and don’t vary the height too much. Remember, we are fighting the plant’s tendency to grow up—if it’s too challenging, it won’t work. Trust me, I learned this the hard way.

When the maze is complete, give your beans a last bit of water, and maybe a kiss, and then close the box. Apply tape along the top edge, to secure it and reduce light. Then put it next to a window and wait.

And wait.

It’s going to take a few weeks. Remember, horticulturists are very patient. Open the box every few days or so to be sure it has not dried out. Add a little water, but only enough to moisten the soil if it is very dry.

When you see the bean plant emerging through the open window in the box, open it and take a look. How long this will take will depend on the kind of beans you use, how far the plant has to grow, and how warm the room is.  

The beans have sprouted and are moving toward the light
The beans have sprouted and are moving toward the light

 It took my beans about five weeks to grow through the second window.

 

PHOTO: all of the bean sprouts are leaning toward the light.
The beans were definitely torn between growing up and growing in the direction of the light.

 

The winning sprouts, which I believe were lentils, did not actually make it through to the last window when I took this picture, and I’m not sure it has enough “umph” to do it. Still, notice how all of the plants leaned toward the light and most of them grew through the first window. That is a positive result!

What is going on here?

This activity demonstrates phototropism. Photo is the Latin word for “light,” and you will remember that a tropism refers to an organism’s response to stimulus, so that phototropism means plants grow toward the light.

It makes sense for plants to reach for the light because they need light to make sugars, their source of energy. Normally, growing up against the pull of gravity is also growing toward the light. In this activity, we changed that condition, forcing the beans to deviate from their normal course to get the light they needed.

The sprouts that grew the farthest and were closest to completing the maze had leggy stems that would not support growth upward to the last window. If I leave them a few more weeks, they could possibly grow along the bottom and then up the side of the box. I’ll have to wait and see.


©2013 Chicago Botanic Garden and my.chicagobotanic.org