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.

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.

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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.

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

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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.

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.

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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.

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.

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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.

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

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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.

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.

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Not all lighting manufacturers understand how to properly measure and present light outputs for plant growth. As the label below shows, the lamp manufacturer included measurements of lux, but no PPF information. In fact, the label mixes up PAR and lux measurements in an attempt to provide PPFD measurements at different distances from the plant. But, as you now know, lux and PAR are distinct measurements.

Unfortunately, far too many lamps include this kind of incorrect information.

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Lettuce is a great candidate for direct seeding. These seeds can be sown directly in the the final pot, without the extra step of transplanting. Be sure to read the seed packet for planting instructions.

After the seedlings germinate, be sure to thin them so they aren't overcrowded in the pot. You can then continue to grow your lettuce in the same container until harvest.

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