Light for an Indoor Herb Garden

Types

• Grow lights provide essential light rays and come in two common varieties. Fluorescent light tubes provide light for the entire length of your herb garden and typically are used in pairs in a single hanging fixture. Compact fluorescent lights offer the power of a fluorescent light tube but in a smaller space, using a curling glass tube that's about the same size as a standard filament light bulb. Specialized LED lighting can also be used, but such fixtures are rare and typically very expensive.

Considerations

• Several factors must be considered before buying a grow light. These will vary depending on the type of herb you wish to grow. The Kelvin value, which refers to a bulb's temperature, comes in cool (blue) and warm (orange) varieties. The higher the Kelvin rating, the cooler the lighting, with 5600 Kelvin coming closest to daylight conditions. Seeds and seedlings typically need cooler lighting, while adults require warmer lighting. Lumen is the amount of light emitted by the source, also known as its brightness. Some bulbs range between 450 and 2,600 lumens, but the appropriate amount will vary according to the plant, with some herbs requiring brighter bulbs. You shouldn't use anything less than 20 watts, since a bulb that weak won't emit enough light to be beneficial.

Spacing

• Light bulbs typically should be positioned about 6 inches above the herb garden. As the plants grow, the lights should be raised to maintain this height. If in pots, the plants should be turned every other day so that each leaf or other parts of the plant will receive equal amounts of light.

Timing

• Since the point of grow lights is to simulate natural sunlight, the timing of lights is crucial to an indoor herb garden. Ideally, gardens should receive approximately 12 hours of simulated sunlight per day. This can be achieved easily with light timers. If the plants are near a window or a place where they already get direct sunlight, the light timers should be adjusted to compensate. For example, if the plants get four hours of direct natural sunlight each day, the fluorescent lights should be on for only around eight hours per day.