What Are High Pressure Sodium Grow Lights and What Do They Do?

Gardeners can be very inventive when they put their minds to it. The concept of grow lights was developed when certain practical problems presented themselves: how does one grow plants indoors? Or how does one grow certain plants that are not suited to local weather that may be more cold and blustery than those plants can tolerate? Enter the concept of grow lights.

What are grow lights?

Simply put these are lights that help plants grow in the absence of natural light. For instance in the winter months, days are short in many regions of the world and this would mean insufficient light for plants to grow. Also some plants are required to be grown indoors because outdoor conditions are inhospitable, so such plants may have no access to natural sunlight. These lights are used for horticulture, aquatic plants, plant propagation and food production.


Grow lights are electric lights that emit electromagnetic spectrum to stimulate growth by enabling photosynthesis. The light emitted is designed to be similar to the rays of the sun. Different grow lights may be used depending upon the type of plant being cultivated and its needs, the stage of cultivation and other factors. They can be industrial strength lights or lights that can be used in the home. Fluorescent lights, incandescent lights, LEDs and high intensity discharge lamps are some of the types of grow lamps.

And what are high pressure sodium grow lights?

High pressure sodium grow lights are most typically used by those who grow flowers and vegetables indoors. This type of grow light emits the light spectrum – white light concentrated in orange/red light to help stimulate growth of flowers and fruit. These lights help improve the reproductive processes of a plant in the flowering and fruiting stages of the plant’s life.

There are benefits of this type of grow light over others such as incandescent bulbs since they are more energy efficient, consuming less power. They also last longer – up to 5 years – and they also have a larger light output.

These growth lamps are best used to supplement natural light in greenhouses and similar settings, rather than as the only source of light for a plant. If they are used continuously, plants tend to become leggy and their branches could become sparser.

You can buy single bulbs or lamps or a grow light system which is a more complicated apparatus. Many have a built in dimmer which makes the light easy to adjust.