Learning About Germination (TOPS Radishes Unit)


I’ve been doing a serious rethink of science around here. Despite having an undergrad degree in science, I have found this to be one of the most frustrating subjects to do consistently and well. (Or even to just do at all.) But I think I may have turned that around in the past few months.

And one of the tools in my fix-science kit has been TOPS science investigation units.

One of the challenges of doing science with children is finding hands-on activities that actually demonstrate some aspect of science. Having used both science kits and curriculum-based science experiments, I can attest that at least 50% of the time pre-packaged or pre-planned demonstrations fail. And this is normal. But most kits or programs don’t prepare us for the failure, so we’re left scrambling to rescue some scientific principle from the shambles.

But TOPS units seem to handle the failures differently, making allowances for them and offering suggestions of how to work with them. I like this.

The Radishes Unit

We just completed the TOPS Radishes Unit, finding it was designed carefully enough to accommodate the inevitable failures. This is a unit aimed at Gr. 3-8; I did it successfully with my 6- and 7- year old daughters, but had to be available to help with a lot of the graphing. The experiment materials were very simple, mainly consisting of some baby food jars, milk cartons, paper towel, tin foil, soil, and of course, radish seeds.

The gist of this unit is to observe, over 4 weeks, germination in radish plants and the effects of different growing conditions on young radish plants. The daily activities guide students in making observations and finding patterns within those observations.

We started by germinating 20 radish seeds, observing all stages of their germination.

Tasha making some observations

Our Process

Right away we hit a problem: our house in late winter was cold enough that the radish seeds wouldn’t germinate as quickly as we were expecting. My daughters and I discussed how we could handle this as scientists, and they decided that one of their germination containers could go on a plant heating mat, while the other would be left at our home’s room temperature. We would compare the difference.

One day into our warmer vs. colder germination environments, we realized that we had created a new problem: the heat mat made it too warm in the growing container, causing the water to evaporate and drying out all of the germinating seeds. We decided to flood the very dry seeds, remove them from the mat, and see what would happen.

Over the course of the next four weeks, we continued with the unit activities, problem solving as we went along. I was worried that our early difficulties would be compounded throughout the four weeks of investigation, but that just wasn’t the case. The unit had been designed to allow general patterns to emerge even with those errors, and the observations led us to find patterns rather than one-off observations.

Daily activities included making grid drawings of radish plants, graphing the germination pattern of seeds, graphing the growth rate of a plant, observing phototropism, and monitoring the effects of a saline and acidic environment on germination. In the process, my daughters became very familiar with the vocabulary of germination. (“Mom, another radicle has popped out!” “Hey, the cotyledons have turned to the window!”) We all oohed and aahed over a seed at work, a process that is usually hidden beneath the soil.


We were all happy using this unit. My girls liked the instructions written to them with cute cartoon characters. They enjoyed observing and thinking like scientists, and did some of their most careful work. I was happy that, despite our hiccups (or maybe because of them), we learned a lot. The effort I put into making this happen was minimal, and it was worth it.

TOPS Radishes 1

Using TOPS

The good news is that many TOPS units are available as an economically-priced download from the TOPS site. For us Canadians, this is a wonderful way to get around the usual shipping hassles. Their customer service is personal and excellent: when I had some trouble with my store cart, they quickly gave me alternative payment and download options.

That said, there are some units where you will definitely want to purchase a TOPS kit containing some of the harder-to-find materials. (Lentil Science would be an example.) You can purchase the kits directly from TOPS, or else through Rainbow Resource Center, where you may be able to reduce shipping costs by buying other materials at the same time.


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