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.
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

Parsnips: Patience Pays Off

Some vegetables are more satisfying than others when it comes to harvest. Parsnips are in that category, as we discovered the other day (just three days before it snowed!), when we harvested a crop that’s been quietly growing in the Regenstein Fruit & Vegetable Garden since April.

PHOTO: A freshly dug parsnip with a long, thin, tap root.
Parsnips have long tap roots that need to be dug gently from the soil.

The sun was out, the air was crisp, and the nights were frosty: parsnip weather. Cold weather is actually a good thing for parsnips—in fact, they need it to convert the starch in their roots to sugar, transforming them from lowly, nose-turned-up roots to gourmet, thumbs-up side dishes. We used a pitchfork to loosen the dirt deeply around each parsnip top—a gentle harvest is required, as parsnips are brittle and can snap if eager hands try to pull the roots by their leaves.

Aren’t they gorgeous? We planted ‘Albion’ this year, a variety that’s creamy white and elegantly long and tapered. Inspired, we’re adding two other varieties to our seed list for next year: ‘Lancer’ and ‘Half-long Guernsey’.

Speaking of seeds, parsnips can be a bit fussy about germination. Knowing that, here’s the strategy we employed for sowing this year:

  • Plant fresh seed. Parsnip seed viability is short, so plant only newly-purchased seed every year.
  • Sow heavily. We’ve found that germination can be spotty in our heavier clay soil. Of course that means we had to…
  • Thin ruthlessly. We thinned four times to guarantee them the wide spacing they need.
  • Mark the rows. A few radish seeds (which germinate in a few days) marked the ends of each parsnip row—which took their sweet time to germinate, in about three weeks.
PHOTO: Freshly dug parsnips.
So satisfying: Some of last week’s parsnip harvest.
Photo by horticulturist Lisa Hilgenberg

Once germinated, parsnips are low-maintenance veggies in the garden—as befits a vegetable that takes 120 days, plus a cold spell, to reach maturity.

A gardener’s patience with parsnips really pays off in the kitchen. How can you serve parsnips?

  • A bowl of parsnip soup.
  • In a roasted root vegetable side dish.
  • As a snack of parsnip “fries,” brushed with coconut oil, sprinkled with salt, and baked in the oven.
  • As a secret ingredient in mashed potatoes.

Or as my chef-friend Brad does, make parsnip cakes for a light main meal or delightful side dish. Here’s his recipe as he knows it by heart:

Boil parsnips in salted water for 3 minutes. Grate with a medium fine blade, then add one egg, white onion, flour, salt, pepper, and lots of Italian parsley. Form pancakes about ½-inch thick and 3 inches wide, and fry in oil on medium heat until parsnips are cooked through and cakes are golden brown and caramelized. Yummy with a roast chicken!

©2013 Chicago Botanic Garden and

The Guerrilla Gardener Comes to the Garden

Richard Reynolds, a self-proclaimed guerilla gardener and blogger, comes to the Garden on Tuesday, February 8 to give us an inside scoop on his involvement with this movement. Check out this video on planting sunflowers in public spaces and then come join the discussion during his presentation. View the video on YouTube here.

For more information and to register, visit