I found this on a random google search where I was actually looking for something else and I know that I have found a few plant growth topics, but this one is a bit different.
The standard practice in schools to test plant growth is to use nutrient deficient solutions on already grown plants, or on cress, and we often find that we don’t get amazing results. Through mainly pinterest, I have found “at home” versions where you use water, salt water, sugar water, vinegar, etc – common household liquids. Obviously, if you’re trying to teach the science behind the nutrients themselves that are needed, the “at home” versions won’t help.
If, however, you just want to introduce how plants grow rather than what they need nutrient-wise to grow, then this newly found solution can easily be added on: aspirin!
Apparently there is loads of research into how aspirin can help tomato plants, but this “science fair” topic is about testing aspirin to see if helps plants grow. This would be a lovely add on to the other household liquids that cress seeds could be grown with.
You just have to be careful with the aspirin when it comes to children. Definitely one to add on to the to-do list!