Your student will test how increasing fertilizer concentration affects both plant height and root length in radishes, using five labeled pots ranging from a 0% control to a 200% solution of balanced liquid fertilizer. The sheet walks through experiment setup, a fertilizer concentration table with exact milliliter measurements for each solution, a data table for recording plant height every two to three days from Day 0 through Day 15, and a final root length row measured at harvest. Designed for grades 5 to 7, this radishes fertilizer concentration experiment introduces controlled variable design at a scale a homeschool student can manage independently over two weeks.

This lab fits naturally into a plant biology unit study covering nutrients, growth factors, or experimental design. It works as a standalone investigation or as a paired comparison alongside a soil amendment or hydroponics experiment you may already have in your curriculum. By completing the analysis section, your student demonstrates the ability to interpret multi-variable data, propose a follow-up hypothesis, and draw a conclusion from real-world observations rather than a textbook diagram.