Gardening Supplies: Lights

• Dayspot Clamp-On Light 150 Watt

• Dayspot Clamp-On Light 60 Watt

• Intelligent Plant Light

• Intelligent Plant Light Bulb

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Lighting for Plants

Grow lights come in many spectrums, prices, and watts. Generally, there are four kinds: incandescent, fluorescent, high pressure sodium (HPS), and metal halide (MH).

High pressure sodium and metal halide are High Intensity Discharge (HID) lights. HID lights are generally for more serious gardeners; the initial cost is high, but it is well worth it. Imagine being able to grow almost anything you want indoors or on your balcony!!

A few things you should consider when deciding whether to invest in a grow light are: Type of plants, square footage, initial cost, operating cost, life of bulb or system, and aesthetics.

A general rule of thumb is that each square foot should receive between 1,000 - 3,000 lumens. Typically, the cheaper the initial cost, the more expensive the operating cost and vice versa.

Here's a summary of the four types of bulbs:

Fluorescent	Spectrum	Lifetime of bulb	Energy Efficiency (Wattage to Lumens)
	varies	10,000 - 20,000 hours	18W, 1,100 4' 40W, 2,960 8' 75W 5,800
	Special Qualities: Fluorescent light is widely dispersed, which means that you have to have them very close to the plant (2") in order for them to be effective. This is sometimes unattractive and bothersome because if your plants grow fast, you have to readjust the height often. Used mostly for sprouting. Available in cool white and full spectrum.

High Pressure Sodium	Spectrum	Lifetime of bulb	Energy Efficiency (Wattage to Lumens)
	Red-Orange Yellow	24,000 hours	150 W, 16,000 250 W, 28,500
	Special Qualities: If you want a lot of fruit and vegetables and don't mind if your plants look a bit strung out, use HPS. Maybe marry a HPS to a fluorescent for a full spectrum to help you plant relax a bit. High Pressure Sodium lamps are available in 50, 75, 150, 400 and 1000 watt sizes.

Metal Halide	Spectrum	Lifetime of bulb	Energy Efficiency (Wattage to Lumens)
	Full Spectrum, Bluish hue	10,000 hours	175 W, 13,000 250 W, 20,500
	Special Qualities: For the natural look and natural speed of things, use metal halide. Metal Halide lamps are available in 175, 200, 400 and 1000 watt sizes. Hopefully they will soon come in smaller watt sizes so that they can be incorporated into small space gardens. Often used in stadiums and photo-shoots, metal halide provide aesthetically pleasing natural lighting for indoors and outdoors.

Determining your Indoor Light Level

Although you could use a light meter to measure how much light you have in your home or office, a blank sheet of white paper, ruler, and some common sense can be just as effective.

First, put the blank sheet of white paper in the spot your plant will go.

Next, hold your hand 12 inches (about 30 centimeters) above the sheet of paper.

If you see a crisp, well-defined shadow... Congratulations! You can grow any indoor plant you want to. (Even plants suited to low light levels are only shade "tolerant." Most of them will thrive in cool, bright light.)

If you see a blurred outline of your hand, you have medium light. You can still grow most indoor plants, but you'll need to invest in additional lights for light-lovers such as succulents, flowering plants, and cacti.

If you can barely see any shadow at all, you have low light. Your plant selection is limited to mostly green leafy indoor plants. To grow a wider selection of plants you'll need to bring in more light.

Aside from proper watering, giving your plant the light level it needs is critical for successful plant growth and survival. If you do bring in additional lights for your plants - put your hand in front of the light source to make sure it's not so hot it will burn the leaves. As a general rule, if you're comfortable, your plant will be happy, too.

Sunlight

There are three intensities of sunlight that suit plants: full sun, partial sun, and shade. Depending on the particular plant, and other plants near it, try to plan for a garden that groups plants that need a particular amount of sunlight together (or plan it to plant taller plants over small ones that need shade).

Other factors related to the type of sunlight are the intensity of the light, the duration of exposure, and the overall quality of the light. The closer to the light source, the more intense the light. So plants that need a lot of light for a long period of time need to be planted in bright areas - such as along a southern window.

The duration of light is more important to some plants (especially those that only flower during the short days of winter) than others.

Partial Sun Conditions

Plants that thrive in partial sun are the plants that will do well with about three to six hours of sunlight a day. If these plants receive too much sun, they have a tendency to heat up and wilt.

Placing partial-sun plants in a west-facing area will give them a bit more sunlight in the afternoon hours, whereas plants that are in east-facing areas receive more light in the morning.

Always check your plants' sunlight requirements (when you buy them or through a garden shop). Partial sun will suit a wide variety of plants, and depending on the water requirements, you can have a garden filled with all kinds of plants!

One way to achieve partial sun for your plants is to plant them near larger plants that provide shade for some of the day and sunlight for a few hours of the day. This is especially helpful if you have a large balcony that has the space to grow some nice shrubs or tiny trees.

Full-Sun Conditions

Plants that need full sun are generally those that thrive in six or more hours of direct sunlight exposure every day.

Heliophilous is the term that describes these plants: helio for "sun," and philous for "to like." Direct, warm, long-lasting sunlight is what this means to a plant.

A south-facing window or balcony will receive the most sun (in the northern hemisphere, that is), assuming that the light is not blocked by other buildings or trees.

A lot of desert plants and cacti fall into the full sun category. Other plants that do especially well in full sun are flowers and most vegetables.

While it is possible to keep full sun plants alive in areas that get less than six hours of direct light a day, the results aren't as good. Plants need all the energy they can get to produce flowers, fruits, and vegetables.

Shade Conditions

Shade is often used to describe situations in which a plant either gets two or three hours of direct light, or gets indirect or filtered light all day.

There are very few plants that actually require shade. Most are better thought of as "shade tolerant," and will usually thrive if placed in partial sun conditions as well.

Most shade plants will wilt or burn if exposed for long periods of time to direct sunlight. Hot, full sun saps the strength and water out of these "shade-loving" plants so be careful!

Shade can be achieved artificially, by building a shade screen for your plants, or by placing them in an area that receives little direct light - such as below other sun-loving plants.

For indoor plants, you can use blinds or thin curtains to provide the filtered light that these plants prefer. Or place them in a north-facing window, or in the center of the room away from sunny windows.