Plants do not use UV radiation for photosynthesis, and it can cause cellular damage and plant death, but there are some benefits to providing small amounts.

Cryptochromes absorb several wavelengths of UV radiation for various beneficial functions. UV damage to plants stimulates them to produce protective antioxidants, resins, oils, and other chemicals that give them flavor. UV light can also toughen up young seedlings so they can more easily transition to higher-intensity lighting without experiencing shock.

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High humidity and water on foliage spreads diseases such as early blight in tomatoes. Early blight also infects eggplant, peppers and potatoes.

Good ventilation and air movement are necessary to reduce disease pressure. Be sure to use fans in enclosed growing spaces and allow enough space between plants to keep the air moving around them.

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There is a lot of variation in how manufacturers measure light quality and the outputs of their lamps, as well as differences in how they determine the electricity measurements they provide. Some incorrectly use the terms PPF and PPFD interchangeably as the same measurement. You can take the science into your own hands and determine accurate measurements with a PAR quantum flux meter.

PAR meters are available with attached and remote sensors so you can measure light in different locations and over different lengths of time.

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Digital ballasts are electronic ballasts containing additional microprocessor that allows them to better regulate the output voltage and current to the lamp. They can be more efficient than other types while using only a third of the energy.

You cannot use digital ballasts with certain systems, such as plasma lighting. They also emit some RFI, but the technology is improving.

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Have you ever struggled with houseplants that turn brown on the tips or edges of their leaves? A lack of humidity indoors can cause many plants to struggle with excess moisture loss. Humidity in the air helps regulate transpiration and water loss or absorption through plants’ leaves.

Tiny seedlings and cuttings are at greater risk for drying out quickly, especially in a dry-air environment. This is why humidity domes are frequently sold with seed-starting kits. It’s crucial to keep humidity levels high around your new seedlings or cuttings, as they have a limited root system (or no roots at all) with which to take up water.

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Want to grow your own microgreens indoors? Direct seed microgreens seed into enclosed seed tray without drainage holes or any shallow container without a hole. Sprinkle seeds across surface of moist soil, or a moist capillary mat, and mist to moisten. Place under bright grow lights for germination.

Create a thick stand of seedlings, but don’t seed so densely that seeds are on top of one another; this will cause air circulation problems. If your room is cold, use a seed heat mat under the seed tray to speed up germination. Use a mist bottle to keep seeds and seedlings moist, but not soggy, as they germinate. Harvest when seedlings have their first set of true leaves!

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Are you growing vining, or indeterminate, tomatoes indoors?You must train vining types of tomatoes onto support cables or trellises that will support their ongoing growth and increased size.

Remember that determinate tomatoes typically grow to about 4 feet tall and 2 feet wide, while indeterminate tomatoes are vines that can grow to anywhere from 6 to 25 feet tall!

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Aquaponic systems use water from the tank, and the waste produced by the fish grown in the tank, that are circulated into the grow bed to feed the plants suspended in the water. The plants then filter the water, which is circulated back to the fish tank.

Aquaponic systems also add the complication of maintaining animal life. They are fascinating, and excellent for growing plants indoors.

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