Why did mendel grow his pea plants in a greenhouse?

Mendel grew his pea plants in a greenhouse to control environmental factors such as temperature, humidity, and light exposure. By controlling these variables, Mendel could ensure that any observed differences in the pea plants were due to genetic factors rather than external influences. This controlled environment allowed Mendel to conduct his experiments with greater precision and accuracy, leading to the groundbreaking discoveries in genetics that he is known for today.