Science Buddies: "Ask an Expert"

How does Vitamin C actually affect plant growth?
I hypothesised that varying Vitamin C concentrations in the solution medium fed to plants would affect their height.

I'm not quite sure what your question is? Is this the question you propose to answer? If it is, the very first question you need to address is "Why would you expect vitamin C to have any effect at all?" Then, "Do plants absorb Vitamin C through their roos, or do they make their own?" You've got some homework to do.