Growing vegetables and herbs for food in a greenhouse can be advantageous. Using a greenhouse to its full potential allows gardeners to plant and harvest new crops year-round instead of having to rely on traditional growing seasons. However, successful greenhouse propagation of vegetables, herbs and fruits requires much more time and effort than seasonal outdoor gardening. The reason is that in a greenhouse you must pollinate plants yourself rather than letting nature take its course.
Plan a gardening schedule for your greenhouse. While it will be somewhat climate-controlled, you will still have to account for seasonal change when planting fruits, herbs and vegetables. Greenhouses are designed to make the most of available sunlight, but winter naturally has less sun and is colder. Some plants thrive in winter temperatures but do not like frost. Plan accordingly, and write it in your notebook.
Plant desired fruit, vegetable and herb seeds in flats according to species planting instructions. Water enough so that soil is wet but not soaked. If the weather is not providing enough sun for the species you've planted, turn on your ultraviolet grow light. Check the instructions on the seed packet to see how many hours of sun each plant prefers.
Transplant seedlings to bigger pots as they are ready for it. Thin overplanted seedlings or transplant them to additional pots. When transplanting, prepare the new pot before beginning to move the seedling from its flat. Fill the new pot with potting soil, leaving a hole in the middle deep enough for the seedling. Gently squeeze the sides of the flat around the seedling to loosen the soil and root bundle. Transplant the seedlings as gently and quickly as possible.
Observe your plants’ flowering times. When it's time to pollinate plants that require it, pollen and flowers will both appear. Use a small, round-headed paintbrush to manually pollinate plants as needed.
Fertilize and water according to individual species instructions. It helps to keep a notebook handy to record all pertinent information regarding the many species of food plants you may be growing.