The trick with taking cuttings, just as with germinating seeds, is to get the cutting to root before the tissue rots or dies. You can speed up the process by using supplemental rooting hormones, which are chemicals found naturally in plant tissues.

Rooting hormones are available in gel or powder form. Dip the base of your cutting into the rooting hormone, making sure to coat the entire tip, and place it in your rooting media or substrate.

Gardening Under Lights Book

Photoperiodically, plants fall into three primary categories: long-day, short-day, and day-neutral. Plants that are not photoperiodic are day-neutral. In other words, long-day plants initiate flower buds when the days grow longer than their critical daylength. Short-day plants will initiate flowering when the days become shorter than their critical daylength.

It’s not the length of daytime, or light, the plants are responding to, but rather the period of uninterrupted darkness. The plant measures the amount of PR phytochrome in its system after a length of darkness. Therefore, long-day plants need short nights to flower, and short-day plants need long nights.

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Some lamps generate more light or more heat than others. Fluorescent lamps, CFLs, and LEDs are typically the easiest options for starting young seedlings, as they generate lower levels of heat than HID lamps and you can place them closer to your tiny plants.

If you site an HPS lamp a few inches away from young seedlings, the intense light and heat will quickly fry them. Once your seedlings grow up, you can employ more intense types of lighting.

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Here are a few key factors you should consider when choosing the type of lamp, or combination of lamps, you will use to grow your plants: the spectrum of light provided; that is, the balance of cool and warm colors and how much of each is provided; the usable quantity of light the lamp provides; the amount of heat output from the lamp; and the amount of light, or the number of hours, you intend to light your plants given their daylength requirements and the lamp’s energy efficiency.

As a general rule, the less expensive the purchase price of the light setup, the more expensive and less effective it is to run. You will get much better results if you provide the right intensity of selective or full-spectrum light that is specific to plant growth.

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A few orchid species require short-day photoperiods in conjunction with cool temperatures to flower, such as some species of Cattleya, Dendrobium, and potentially some species of Phalaenopsis.

For these types, you’ll need to combine cooler temperatures and shorter daylengths from midfall through winter, then lengthen your lighting period again in spring.

New BOOK! Gardening Under Lights: The Complete Guide for Indoor Growers

Not all plants will thrive indoors without supplemental light, but there are a few easy and tough houseplants that will tolerate low light conditions in your home. Snake plant (also known as Mother in law's tongue) or Sansevieria spp., are one of the best plant choices for low light. There are many varieties to choose from, ranging from large to compact.

There are significant differences in light intensity as you move away from windows and between the rooms in your home. A plant that thrives in the windowsill may struggle just a few feet away. So be sure to pay attention to how your plants is growing...or not growing...after you place it in a low light area. If it's struggling, move it closer to the window.

New BOOK! Gardening Under Lights: The Complete Guide for Indoor Growers

Kelvin temperature is used to describe the visual color of light that a lamp emits. Technically, it is a measure of how white a piece of tungsten steel is when it’s heated to a specific temperature in degrees Kelvin. A lamp with a Kelvin measurement of more than 5000 Kelvin (K) produces more light in the cool blue spectrum.

Lamps with a lower measurement, in the 3000K or lower range, produce more light in the warm red spectrum. Kelvin temperature is not a measurement of actual hotness or coolness of the lamp, but rather the visual temperature of light, which can have a big impact on how your indoor space looks.

Gardening Under Lights Book

In some cases, every place that a plant leaf is wounded is an opportunity for rooting. This begonia leaf below has been damaged, which caused it to develop tiny baby plantlets along the leaf vein.

Now, the leaf can be laid flat on the soil surface, and the little plantlets will begin to root.