How-to
Garden Stories
How to Train Your Plant II
Blog followers will remember that in the first 鈥淗ow to Train Your Plant鈥 post, we demonstrated how plants respond to the gravitational pull of the earth. Geotropism is difficult to overcome, but that didn鈥檛 stop me from trying to make a plant grow sideways through a maze. You can try this activity at home.
Needed items
- a shoebox (or any kind of box)
- cardboard to make dividers
- duct tape (or any opaque tape)
- soaked bean seeds鈥擨 used different beans from a soup mix
- a container with soil
You鈥檒l 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鈥檒l want these to fit as snugly as possible inside the box, but they don鈥檛 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.
Pardon the crude appearance of this maze. I wasn鈥檛 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 鈥渞ace.鈥 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鈥檛 vary the height too much. Remember, we are fighting the plant鈥檚 tendency to grow up鈥攊f it鈥檚 too challenging, it won鈥檛 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鈥檚 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
It took my beans about five weeks to grow through the second window.
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鈥檓 not sure it has enough 鈥渦mph鈥 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 鈥渓ight,鈥 and you will remember that a tropism refers to an organism鈥檚 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鈥檒l have to wait and see.