Electronic Ballasts for Grow Lamps

February 9, 2019

Electronic ballasts will help your lamps run cooler and more efficiently, so a significant percentage of the energy the lamp draws can be converted to usable light. They regulate both the electrical current and the frequency, thus eliminating lamp flickering.

Electronic Ballast
PC: Sunlight Supply, Inc.

Electronic ballasts are adjustable, so you can use them with lamps of varying wattages, which is quite handy for switching out lamps for different stages of plant growth.

Gardening Under Lights Book

Lettuce Seeds Need Light to Germinate

February 8, 2019

Plants that evolved to have their seeds exposed to the soil surface after dropping are adapted to germinating in the presence of light. Lettuce seeds, for example, need to be exposed to red light or they won’t sprout.

PC: Leslie F. Halleck

Sprinkle lettuce seeds on the surface of the soil and lightly press them down, but don’t cover them with soil. Check the seed packet for information about germination light (or dark) requirements before starting your trays.

Gardening Under Lights Book

Can You Grow Different Orchid Types Together?

February 7, 2019

If you love orchids, you have probably realized you must choose your orchid varieties by their temperature preferences. It’s very tough to grow and flower different species in the same environment when they have individual temperature needs.

It’s fun to display blooming orchids together, but different species have different long-term temperature and humidity needs.​
PC: Leslie F. Halleck

You can certainly display many different types of orchids together when they are blooming, but then you may need to separate them after flowering to put them back into their ideal growing conditions and light.

Gardening Under Lights Book

LED Grow Lamps Can Generate Less Heat

February 6, 2019

When you are growing plants that need a more concentrated delivery of light (such as seedlings), the closer you can place your lights without burning them, the better. Smaller LEDs generate less heat than other grow lamps and can be placed closer to your plants. Lower heat output with heat emitting from the back of the fixture means less heat directed to the canopy of your plants.

PC: Sunlight Supply, Inc.

But keep in mind that larger LED rigs can still generate heat, especially in enclosed growing spaces.

Gardening Under Lights Book

What are Dual-Band LEDs?

February 5, 2019

Dual-band LEDs that mix primarily red and blue light produce light that looks pink to purple in color. You can use this mixture for continuous growth through vegetative and flowering stages.

PC: Leslie F. Halleck

You can also use single-band nanometer-specific blue LEDs for vegetative growth, then add red if your plants need to flower. Or bulk up young vegetative plants using single-band red LEDs, then add in blue light to encourage flowering.

Gardening Under Lights Book

Flexible LED Grow Light Strips

February 4, 2019

LEDs lamps are available in other configurations: large multiband fixtures for inside grow tents and grow rooms, light bars you can mount or hang from shelves or cabinets, and even flexible strips you can wind around fixtures you build or the inside of grow tents or closets.

Flexible LED strips can be hung or mounted to fit areas that are hard to light.
PC: Leslie F. Halleck

You can also use LED strips to build your own LED hanging fixtures. These options give you the ability to interlight plants, or to run lighting between plants to improve growth on the lower areas.

Gardening Under Lights Book

Dual Lamp Grow Light Fixture

February 3, 2019

There are also dual-watt and dual-lamp fixtures that allow you to use lamps of varying wattages and switch between MH and HPS lamps in the same fixture.

A fixture that allows you to use either MH or HPS lamps of different wattages allows you to switch easily between lamps in the same growing space.
PC: Leslie F. Halleck

This is handy if you are transitioning young seedlings, cuttings, or plants in their vegetative phase to mature fruiting plants that consume more energy.

Gardening Under Lights Book

Grow Lights: What is Yield Photon Curve?

February 2, 2019

The difference in the efficacy of the varied color spectrums of light on actual photosynthesis is called the quantum efficiency curve, or yield photon flux (YPF) curve.

A full-spectrum sensor measuring PAR from blue and red LED lamps.
PC: Elisa Wilde

If you take measurements using a standard quantum flux meter under a lamp that generates only blue light, you are going to get good PPF and PPFD values, even though blue light is less efficient at stimulating photosynthesis than red light.

Gardening Under Lights Book

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