Any gardener can get started in greenhouse gardening, even without a greenhouse. A corner of a basement, garage or tool shed will work fine, as long as it's heated and will stay between 60 and 80 degrees on its own.
Place plants on any bench or freestanding shelving unit within reach of an electrical outlet. Position the grow lights just a few inches above the plants.
Seedling trays can be placed on heating mats (Image 1) to maintain perfect temperature of around 70 degrees Fahrenheit. Some even feature a thermostat for total temperature control. Keep the plants watered, adjust the grow lights upward as the plants grow (Image 2) and move plants to the garden when they're ready.