Plants need several things to grow, including:

• Light: Plants use light energy to make a type of sugar called glucose, which they use as their energy source. They absorb light through a green pigment called chlorophyll in their leaf cells called chloroplasts.

• Water: Plants need water for photosynthesis, and it also helps move nutrients from the soil into the plant. Water is absorbed by the roots and travels through the plants stems to the chloroplasts in the leaves. Too little or too much water can be harmful to plants.

• Air: Plants need air to breathe, just like humans and animals. They take in carbon dioxide from the air for making food (photosynthesis) and release oxygen.

• Nutrients: Plants need nutrients, such as nitrogen, phosphorus, and potassium, to grow. These nutrients are normally taken up through the roots from the soil. In natural ecosystems, nutrients are naturally cycled, but agriculture disrupts this balance, and humans use plants to mine nutrients out of the soil.

• Temperature: Temperature is important for plant growth, and most plants prefer cooler nighttime temperatures and warmer daytime temperatures. Extreme temperatures can inhibit plant growth in many regions.

• Space: Plants need space for their roots to spread out and absorb water and nutrients, and for their leaves to access light. Overcrowded plants tend to be less healthy and more likely to suffer from disease.

All of these factors are essential for plant growth, and the lack of one essential component can determine the health of a plant. This factor is referred to as a limiting factor, and it applies to all aspects of a plants interaction with its habitat.