When a seed takes in water, swells, and sprouts into a new plant, soil temperature plays a big role in how fast that happens. Warmer soil speeds up germination noticeably — seeds in heated pots at 32 degrees Celsius sprouted a full day before those kept at cooler temperatures. This experiment tests three temperature groups to measure exactly how much that difference matters.

To test whether soil temperature affects sprouting speed, you must keep every other condition the same. All six pots hold the same type of soil and seeds. You water all pots on the same schedule. Temperature is the only thing that differs across the three groups. Because everything else stays constant, you can trust that the heated pots sprouted first because of the warmth.