What Light Brightness Makes Plants Grow the Best?

Quality

One of the most important considerations regarding lighting for plants is the quality of the light. The various light wave colors making up light are collectively referred to as the quality of the light. Plants require certain colors of light wavelengths, and if they don't get what they need, no amount of brightness will cause the plants to grow properly. Foliage plants must have blue light waves, and flowers and fruit plants require red light waves. These are present in sunlight but lacking in some types of artificial lighting.

This is a measure of how bright the light is. The wattage of a bulb indicates the level of light intensity for that bulb. The higher the wattage, the brighter the light. If a bulb has a lower wattage, the amount of light reaching the plant can be increased in a couple of different ways. Since the intensity of the light drops off rapidly as the light source moves away from the plant, if the light is closer to the plant, it will receive the same amount of light as from a brighter bulb placed further away. Another way to make up for a lower wattage light is to increase the duration of the light up to 18 hours per day.

Some plants prefer shady or low-light conditions and will not do well with bright light. The leaves on these plants may look burnt or scalded instead of a rich green color. This is an indicator that the plant is receiving too much light and needs a lower level of illumination. It is always best to research what type of light a plant requires before assuming all plants need very bright light.

Plants that need a lot of light should be in a very bright location, such as a south-facing window or directly under a very bright light. Those that need less intense lighting can be further from the same window or in a window that faces east or west. Artificial lighting does not need to be as strong for such plants. Plants that require very little light can be placed well away from direct lighting sources, and often normal room or office lighting will be enough for these.