When growing plants indoors, it is critical to understand how temperature affects your crops and how to manipulate it to improve your yields. I monitor the temperature and humidity closely in order to provide the correct conditions for each crop to thrive and produce.

Use a thermometer with a humidity gauge to keep an eye on ideal growing conditions.

Gardening Under Lights Book

Watts tell you how much energy your lamp is using and how expensive it may be for you to run the lamp. You can use watts to estimate the size or quantity of lights you may need. While a lamp can seem very powerful because it uses many watts, if it is not efficient, it may convert too much of that electricity into unwanted heat instead of light.

If you base your lighting choices purely on wattage, you may end up with an unnecessarily large electricity bill and a lot of wasted energy in the form of unwanted heat.

Gardening Under Lights Book

There are a few tricks to growing great cucumbers indoors. Cucumbers are day-neutral, and will flower and fruit under a variety of photoperiods and you can grow them successfully with anywhere from 12 to 18 hours of light.

If you’re growing cucumbers inside a grow tent and temperatures are warmer during the day, be sure night temperatures are cooler. Cucumbers can handle warm conditions, but perform best at temperatures between 70°F and 75°F (21–24°C). Keep plants consistently watered at all times to avoid blossom end rot.

Unless you happen to have bees buzzing around in your house or grow tent, you're going to have to do some hand pollination on your cucumber plants. Use a small paintbrush to transfer pollen from male flowers to female flowers.

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

Some seeds are more difficult to germinate than others because they have a very hard, protective seed coat. While most annual vegetable seeds do not require any special preparation for germination, seeds of some natives, perennials, and fruits require a bit of extra work, whether soaking, scarification, or stratification.

Research the plant you want to germinate to determine whether it needs any chitting, scarification, or dry or moist stratification to germinate successfully.

Gardening Under Lights Book

Temperature can trigger flowering in some plants. As temperatures cool, respiration slows and sugar storage increases in some plants. Warming temperatures, after this period of cold, can break the dormancy.

Temperature also influences fruit set, fruit ripening, flavor, and even flower color and size.

Gardening Under Lights Book

A CFL is a good option if you want the efficiency and effectiveness of a fluorescent lamp but prefer to use a spotlight fixture, track lighting, or other directional lamp for a group of houseplants or a single large houseplant. CFLs look like a twisted or folded-up fluorescent tube.

If you have big plants or an expansive grow area, or are growing inside a grow tent or a closet, you can use larger CFLs with light reflectors to spread the light over a larger area and quantity of plants.

Gardening Under Lights Book

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 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

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.

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