While we all know plants need light to survive, some plants need more and some less, direct and indirect, and it can get a little confusing when you’re trying to take care of everyone. So what actually happens for plants when they get the right light?

Photosynthesis

Up first are the basics: plants create their own food source by turning light into energy by combining it with water and carbon dioxide (CO₂) to create glucose. Without enough light, indoor plants can’t produce enough food, making it impossible for them to thrive, reproduce, and even sustain life. Yet, with enough light, plants are able to absorb carbon dioxide through tiny holes called stomata mostly found in the epidermis of leaves. At the same time, exposure to light produces a chemical response in the plant that breaks down the gas and water inside the plant. This combination is what produces sugar and oxygen, disposing of oxygen for us and allowing the plant to use the sugar as energy for growth and repair.

Highly adaptable, most plants are able to survive even without adequate light because they slow down photosynthesis – almost like putting themselves on rations. It’s important to take note of what optimal light conditions are for you plant so you can offer it the intensity and exposure it needs to thrive.

Phototropism

Have you ever noticed your plants leaning in one direction over another? This is called phototropism and it’s when your plant moves in response to a light source. In order to make tilting possible the plant's cells elongate, allowing the stem to move closer toward the light. It’s sort of like your plant trying to be independent and take care of itself.

Phytochrome

Phytochromes are a type of photoreceptor in plants (usually they express as a blue-green pigment) that they use to detect light. These photoreceptors are sensitive to temperature and also help the plant to germinate. How efficient these photoreceptors are affects things like chlorophyll, shape, number and movement of leaves, and when the plant may flower.