LIGHT - the magic of plants!

Through the incredible, magical process of photosynthesis, plants are able to use the power of light to convert carbon dioxide (the stuff we breathe out) into energy. This energy is used by the plants to produce what they need for growth.

Light from the sun is called "full-spectrum", meaning it has all of the wavelengths of color for every phase of plant growth. Indoor lighting, however, only provides a limited range of light depending on how the bulb is made. Wavelengths of color are measured in degrees using the Kelvin scale.

For example, a bright light can be made to give off light at 6500 degrees Kelvin. This is the best light for growing leaves and stems (vegetative growth). A soft colored light may be made to provide 2700 degrees Kelvin. This range is good for promoting flowering and fruit.


Indoor light is also measured by the amount of light being generated by the bulb. The unit of measurement is called a lumen. A house-hold bulb usually provides about 1500 lumens of light. For healthy, vigorous vegetable plants, this is not enough. Most grow lamps should provide 3000 - 7000 lumens depending on the type of plant and the size of the growing area.

Two types of grow lamps that have been used successfully in indoor Container Gardening are the T5 fluoresent tubes and the compact fluoresent lights (CFL). Two T5 tubes in a 24 inch fixture with a reflector will deliver about 4000 lumens over a 1' x 2' growing area. This is sufficient light for growing most salad greens in shallow trays. For indoor garden vegetables you will want to grow in a larger area with deeper containers. The CFL bulb with a reflector will work better for this growing arrangement.

There are other commercial light solutions such as LED, Metal Halide and High Pressure Sodium but they are for larger production and are not well suited for small scale Container Gardening. The Garden Grow Box and the Salad Greens Growing Kit are two examples of proper lighting systems.


What Plants Want

Insufficient lighting will result in thin wispy stems that cannot support themselves and in growth that leans toward the light.

Proper lighting includes the right intensity and appropriate wavelength depending on the type of desired growth.