. Growing two plants without plant food at all doesn't count; in order to see if the new food is better, he must also grow plants with the original food in order to compare it.
have an independent variable. This is the type of plant food. It's independent because he has direct control over it.give plants the same conditions besides food: same water (amount), same light exposure, same temperature, etc.
choose a quantitative way to measure how much the plants grew, like mass or length.i need brainlest anwser to rank up help
