As far as how many watts are needed per square foot for indoor LED grow lights there is no clear-cut answer. How many watts you need has a number of determining factors just like anything to do with indoor farming. There are a significant number of variables. You're going to need to know your plant type requirements, size of your grow area or tent, installation height and light's capabilities.

The Type of Plants

The type of plant you're trying to grow will determine the amount of light they need. All different plants have different lighting intensity and exposure levels. For a basic understanding and guide there are two categorizations for plants high and low level light plants.

High Level Light Plants: Tomatoes, Peppers, Croton, etc.

Low Level Light Plants: Leafy Greens herbs, basil, lettuce, ivy, etc.

As a general rule, leafy greens are lower light level; plants and brighter more colorful flowers and vegetables require higher light levels. So be sure to research and look up your plant's lighting requirements as this would be a good way to start in determining your Watts per square ft measurement.

Which Growth Phase

Seedlings, vegetative and flowering are the three growth stages for plants. Each phase has their own lighting requirements.

Seedlings: The lowest amount of light needed for this phase in terms of intensity and exposure.

Vegetative: Gradual increase from the seedling phase, to look at it simply a slight increase on the seedling's lighting phase and can be referred to as medium light exposure and intensity. It's important to remember to increase the light intensity and exposure gradually from seedling to vegetative. Just suddenly jumping up may create growth problems or light burn.

Flowering: Flowering phase requires the most light. The highest intensity from your indoor grow lights will be needed for this phase. Usually your LED grow light will be moved closer to the plants increasing the intensity.

Disclaimer

Before we outline the Watts per square ft we should acknowledge that Watts is an outdated way of measuring indoor and LED grow lights for your plants. The Wattage is just the energy consumed by the light to work and does not particularly translate directly into their effect on plant growth. However, the wattage of an indoor grow light can give you an idea of the size of the light.

Watts Per Square Ft

Using the estimations below are for the flowering phase of using indoor LED grow lights per square foot. If you're thinking about plants in their vegetative stage maybe reduce the wattage by 50%.

The number of plants, space used (square ft) Wattage from wall.

This table is based around plants needing around 32 watts per square foot for flowering.

However this table is a rough estimate for those of you wishing to switch over to LED grow lights.

Conclusion

In conclusion using Watts per square foot is an outdated measurement for indoor growing. Indoor plant growing has many variables including the plant type, size, number as well as many other environmental conditions. Are you using a tent or light reflectors? Each of these variables will also have an impact on the quality and size of your yield when you grow so if you are looking to grow most optimally you should look into each of the considerations listed in this blog too. Watts per square foot is not particularly useful when you realize how many other factors there are to consider. So if you really want to grow optimally you need to consider all of the factors contributing to your plant's growth cycle. Not just the watts of the light. Watts is just a measurement of energy consumed by the light it has very little reflection on determining your plant's ability to grow.

What is the Best Light For Helping Plants Grow?

SGLEDs indoor full spectrum bulbs can help your plants flourish during any stage of their growth cycle. SGLEDs 36W full spectrum can be used to cover all size grows and numbers of plants due to their even beam distribution and simple installation. If you're looking to complete small, medium or large scale grows these bulbs can be applied in every circumstance. Their dimensions compared to their PAR and PPFD output is incomparable to most LED brands on the market. They can distribute high powered natural beams that will encourage growth of your plants.

If you're looking to replicate natural sunlight indoors with simple cool running lights SGLEDs indoor full spectrum grow lights may be the solution to your plants this winter: