Indroduction to Grow Lights
There are two basic types of Grow Lights; Metal Halide (halide) and the High Pressure Sodium (sodium). It is possible to grow your garden from seed (or cutting) to harvest with either lamp. That said, the decision to choose one lamp over the other depends on your personal gardening style and what results are expected.
The blue/white spectrum of the Metal Halide is recommended for strong vegetative
growth, compacted green growth that will not go to seed. This includes plants
such as lettuce, basil, herbs, house plants, etc. that you do not want to
bolt to seed or produce flowers. The red/orange/yellow spectrum of the High
Pressure Sodium is best suited for fruiting plants that you want to seed
such as tomatoes, peppers, cucumbers, flowers, flowering house plants, etc.
Recent technology has combined these spectrums into “WARM HALIDES” with added reds and “COOL SODIUMS” with added blues. An Agrosun® bulb and a SunMaster bulb are known as “WARM HALIDES” with Kelvin temperatures (Kelvin temperature is an expression in degrees used to show the color(spectrum) of light emitted by a lamp. The sun is approximately 5780K.) averaging from 2700 to 3000 (2.7K to 3K). These bulbs promote more flowering/fruiting sites than standard Halides. A Hortilux bulb and a Son Agro bulb are known as “COOL SODIUMS” with added blues for more bushiness or compactedness, stronger tissue growth and increased leaf growth. These bulbs average Kelvin temperatures between 2100 (2.1K) and 2500 (2.5K).
There are now three options available to you:
1. For a very healthy flowering plant, you can begin with the Halide bulb to encourage strong, compacted, lush leaf growth and then introduce a HIGH PRESSURE SODIUM “CONVERSION” lamp (replaces halide) to encourage large amounts of flower/fruit sites for plants such as peppers, tomatoes, cucumbers, flowers, flowering houseplants, etc. Or
2. You may choose to grow from seed (or cutting) to harvest with a “WARM HALIDE” bulb, which also encourages higher flower/fruiting site yields Or
3. You may choose to grow from seed (or cutting) to harvest with a “COOL
SODIUM” bulb which will encourage more vegetative growth compared to
a standard sodium .
NOTE: While any of these lamps is an excellent choice, halides always encourage
primarily vegetative growth and sodiums always encourage primarily fruit/flower
sites. We hope you find this information useful. Please refer to the Grow
Light Glossary and the Kelvin temperature chart for more information. Happy
Growing!
