The first step in creating an indoor garden is getting a light source

Just as our ecosystem revolves around our sun, so too does your indoor garden. Whether you are using a bright window sill, a small fluorescent light or a powerful High Intensity Discharge grow light, this is the most important consideration for your home garden project. The amount of light you have will determine what size of garden you can grow and what type of plants you can put into it.

This page will help you understand how lighting works and how much is required. Read on  about what types of lights you can use and what you can use them for.

The easiest way to setup artificial lighting for an indoor garden is to remember these rules of thumb. 40 watts per square foot for high light plants like tomatoes and peppers and 25 watts per square foot for low light plants like lettuce and leafy plants.

This means for a typical 4′ x 4′ space, you would need 400 watts of lighting to grow low light loving plants, and 600 watts of lighting to grow high yield plants like large tomato and pepper plants.

That is really all there is to it! The larger scale you go to, the more costly and complicated it gets. Here is a rundown of the different lighting types and their best uses.


Fluorescents come in a number of different styles and shapes, however, they all produce light through the same mechanism. Fluorescents are available in many different light output colours. Typically 6400 Kelvin color temperature is used for vegetative growth, seedlings and cuttings while 2700Kelvin is used for flowering.

T5 Fluorescent


Here is an example of a T5 fluorescent garden. It is growing leafy green vegetables as well as some tomato seedlings to be put outside in our garden. This type of lighting is great because it produces little heat and plants absolutely love this type of light. The drawbacks would be the expense of changing bulbs which should be changed yearly for optimum performance.


Compact Fluorescent

Compact fluorescent is very similar to other fluorescent lighting but packs more power into a small space. These bulbs can get as large as 200watts.

Sun Blaster CFL

Induction Fluorescent

Although not a new type of light bulb, induction fluorescents are gaining popularity in the horticulture world. Induction lamps produce a similar type of light to modern fluorescent lights, with the major improvements being lamp life (over 10 years), PAR light efficiency, and low heat production. Induction fluorescents are part of a new wave of more efficient lighting sources that have been introduced to the horticulture market. Traditional light sources like HPS create a great amount of heat, which is wasted energy, as well as requiring frequent expensive lamp changes.

With a long life, perfect spectral out put for plants and low heat, the only draw backs on the Induction Fluorescent lights are their lack of intensity compared with large wattage HID’s. Although induction lights get more light per watt than HID’s, the induction light has less intensity therefore limiting the height of plants by a small margin.

High Intensity Discharge Lights (MH or HPS)


This type of lighting is easily the most popular for seasoned indoor gardeners. Metal Halide (MH) and High Pressure Sodium (HPS) lights have been used by commercial growers and hobby indoor gardeners for the last three decades for a reason. The high intensity of light produced by these lights makes them the closest artificial light to natural sunlight. High intensity is important to indoor gardening because the higher the intensity, the taller the plant you can successfully grow. The drawback of this type of lighting is that it produces a higher level of heat and therefore can create a heat problem which must be dealt with. For open areas with one lamp, the heat would not build up and would not cause any concern.

The two types of HID’s (HPS and MH) produce different colors of light. MH produces a blue light best suited to leafy type plants such as lettuce or other vegetative plants like young peppers etc. HPS produces an orange light best suited to flowering plants like fruit trees, ornamental flowers, or flowering tomatoes and peppers.

Light Emitting Diode (LED)

Easily the most controversial grow light on the market, LED grow lamps have really improved from their original designs. Touted as the newest and best grow light, many early adopters of this technology were very disappointed with their results. The biggest attraction to LEDs are their low heat output, and PAR light efficiency, but at the time, the understanding of a plant’s light needs, and LED design kept LEDs from reaching their true potential.

Now however, with higher power LED systems and better light spectrums, LEDs are now a viable option for small indoor gardens.