Monday, March 14, 2005

Growing Things

We spent today planting.

Last week, the kids designed experiments to find out how different variables* affect the growth of Wisconsin Fast Plants. I have groups comparing different quantities of fertilizer, the pH of the water they are using to water the plants, the number of seeds per cell, the color of light, etc.

Wisconsin FastPlants are a growing system designed just for teachers. You get little styrofoam quads - four cells each - along with seeds, fertilizer, potting mix ("Ms. Frizzle, what's potting mix?" "The soil." "I TOLD you it was the soil!"), plastic shoeboxes, water mats, water wicks, wooden sticks & plastic rings for supporting the plants as they grow, and - get this - dried bees which you are supposed to glue to sticks and then use to pollinate the plants for genetics experiments.

Basically, the kids plant the seeds according to the instruction manual, then they set up the watering system. This is a plastic shoebox full of water & anti-algal chemicals, with a plastic lid that has a hole in one end. You saturate a felt water mat, then drape it over the lid of the shoebox so that one end of the mat hangs down through the hole into the water. Water gets drawn up the mat, then into the wicks which you have placed in each quad underneath the soil. The plants water themselves!

My students who are watering the plants with different solutions will use the watering system on weekends but will water the plants with an eyedropper during the week.

We also have special lighting systems which are like large crates that have lights hanging down from above. A team of eighth graders is helping me assemble these during lunchtime, for community service hours. Some kids are testing how different colored light affects plant growth, so they are going to have to wrap cellophane around a ringstand in such a way as to make a colored filter to go between the plants and the light. It won't be perfect, but it should work well enough.

In my experience, Wisconsin FastPlants grow right on schedule - they sprout within a few days and their whole lifecycle takes just a few weeks. The only problem is that the planting process takes my kids a FULL hour. It took them the full hour even though they had been given the planting instructions to preview last week. My room looked like an explosion of soil and water by the end of the day.

I'll try to bring my camera to school from time-to-time over the next few weeks so you can get an idea of how this is all going...

*See Number2Pencil for a good explanation of independent & dependent variables, by the way, two concepts which, no matter how many times & how many ways I explain them, remain confusing to my middle schoolers. Consensus among science teachers at the Exploratorium this summer was to just keep hitting them with the concept in experiment after experiment, question after question, until they all finally get it. Variables are necessary to every experiment, so its not like you're dumbing anything down for the kids who figure it out quickly.

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