Science Buddies: "Ask an Expert"

Hello, I pray all is well.
We have a question concerning the Kalanchoe plants. 2 plants outside, 2 plants in window sill & 2 plants in darkness of closet. We’re measuring growth and blooming. Do you think this is sufficient or should we also include fertilizer in 2 of the plants?
Your feedback is appreciated.
Thank you

Hello,
I would not recommend adding fertilizer to only two plants because that changes too many things about your experiment. Either put fertilizer in all or none. Let me know if the helps!

Hi, thank you for your reply.

Hello,
Adding a different variable to just one group will completely chance the results and accuracy of your experiment. The fertilized plant can't then be compared to the rest of the groups unless you put fertilizer in all of the plants in the different environments.