Some fluorescent grow lamps are available with spectrums weighted to specific color ranges, such as red or blue.

Fluorescent grow lamps are available in distinctively warmer spectrums, as well as full-spectrum forms that provide a better balance of light across the entire PAR light spectrum, which allow you to grow plants more effectively through their vegetative and flowering phases.

Gardening Under Lights Book

The length of time you leave your lights on is just as important as the type and intensity of light you provide. Many plants are photoperiodic, meaning they require different durations of light and darkness to shift into different phases of growth or development, such as producing flower buds or forming bulbs.

Most plants require a minimum of 10 hours of light each day for active growth. While your plant might survive with less, it may go into a dormant state if you leave it at that photoperiod for an extended time.

Gardening Under Lights Book

Many indoor growers choose to skip the soil and grow their plants in hydroponic, aeroponic, or aquaponic systems. While growing hydroponically will reduce some of the pressure of checking your plants daily for water needs, you will have monitor the system.

The most common form of hydroponic system is the nutrient film technique (NFT), which involves growing plants with their roots directly suspended in water. Other methods include wick, water culture, ebb and flow, drip, and aeroponics.

Gardening Under Lights Book!

The light source must be very close to your seedlings as they germinate, as near as 3 or 4 inches from the seeds as they emerge from the soil. These tiny seedlings are too far from the grow lights above – they will soon become too stretched if not moved closer to the light.

Ratcheted cords or chains that allow you to move light fixtures up and down will enable you to place your lamps very close to seedlings as they are just emerging, then lift the light source as they grow.

Gardening Under Lights Book

If you are growing warm-season crops—such as basil, tomatoes, or peppers—from seed indoors during cold winter months, you must warm their soil. Ultimately, your goal is to get as many seeds to germinate as quickly as possible. For crops that need warmer soil temperatures, especially when you’re starting them indoors during colder months, a seedling heat mat can speed up the germination process and ensure success.

Heat mats, which are placed directly under your seed tray, can warm soil to an average of 15 to 20 degrees Fahrenheit above room temperature. Be sure to use a heat mat specifically designed for seed germination. Seedling heat mats are insulated and moisture-resistant, so you can place them on normal surfaces under your seed trays.

Gardening Under Lights Book

While many succulents can't be grown long term indoors, due to a lack of light, there are some species that can tolerate indoor growing without grow lights. When you're gardening under lights indoors, it's good to know which plants can tolerate lower light conditions.

Haworthia are one type of succulent that can tolerate lower lighting, and can be maintained in a bright windowsill. Haworthia are compact succulents that grow in a whorl of foliage. Their shallow root systems make them perfect for keeping in small pots as easy-care houseplants.

Gardening Under Lights Book

A smaller two- to four-lamp fluorescent fixture can sit just a few inches above young seedlings. As plants grow larger, move the fixture a foot or so higher. Large fluorescent fixtures may need to be 2 to 3 feet above plants to avoid causing heat stress.

I use a large adjustable shelf with 4-lamp T5 fixtures to start seeds, grow microgreens, transition transplants. You might find large fixtures like these can get pretty warm so you may not need a seedling heat mat, or you can remove one or two bulbs to reduce light and heat load if it seems your young seedlings need a bit less of either.

Gardening Under Lights Book

Plants have varying requirements for how, where, and when to take cuttings, the ideal size of the cuttings, and how long they may take to root. Some plants, such as succulents, will root from the base of a leaf. Others, like begonias and African violets, will root straight from the leaf surface.

Many perennials are propagated by taking root cuttings or divisions. You can propagate certain tropicals, such as pothos ivy, by setting a stem in water for a few weeks.

Gardening Under Lights Book