Plant Competition
Plant Competition is what happens when too many plants grow close and must share light, water, and food.
Six glasses stand in a row on a counter, each with the same small amount of water. Crowd them together, and the ones in the middle get less light from the window. The outer glasses stay bright, but the middle ones sit in shadow. Tall plants do the same — they block light and pull water, leaving short plants with less of both.
Explaining plant competition by grade level
Think of seeds packed tight in one small pot. Each plant needs sun and water to grow. When too many plants share one spot, none of them grow as tall. The crowded plants end up short and thin.
Projects that explore plant competition
When too many plants share a small space, each one competes for the same light, water, and nutrients in the soil. Packing 20 radish seeds just half a centimeter apart forces them to split those limited resources. As a result, the crowded plants end up shorter and less full than those with more room to grow.
Crowding changes how plants grow over time, as spreading roots and overlapping leaves force each plant to compete harder for water, light, and food in the soil. Garlic chives planted at high density sprout quickly at first, and by day 6 all the pots reach about the same height. After that, the less crowded pots pull ahead — each plant there gets a bigger share of resources, so they grow taller.