Not only is greenhouse gardening an ideal way to grow crops and flowers year-round without having to worry about weather elements, it also gives you the chance to create a living environment specific for what you want to grow. Under the right conditions, you can grow almost anything in a greenhouse. When gardening in a greenhouse, the key is to establish a ventilation system.
Establish a heating system if necessary. This is really only used in regions that have severe winters. There are two choices for heating systems: an active system or a passive system. An active system needs an energy source from electricity or gas. A passive system is generated by solar energy. Deciding on what system you want to have depends on factors such as the size of your greenhouse and budget.
Establish a circulation system as greenhouses must have ventilation in order to be successful. Circulation prevents disease and mold, but make sure that no more than 25 percent of the greenhouse surface is given to circulation if it is through manual vents. There are two types of ventilation systems you can use. Natural ventilation utilizes roof vents and side vents; warm air rises to escape through the top, bringing cool air in through the sides. The second type is mechanical ventilation, which utilizes an exhaust fan to move air out one end of the greenhouse while air from outdoors comes through motorized inlet vents on the side. Keep in mind that exhaust fans need to be sized to exchange the total air volume in the greenhouse every minute.
Maintain the temperature in your greenhouse during summer and winter. This all depends how much you use the greenhouse and your regional temperatures. Since air movement through ventilation may not be enough in the middle of the summer, you need to lower the temperature with methods such as evaporative cooling (small coolers with a fan and evaporative pad that cools air and ups humidity) or shading from the sun (with roll-up screens or vinyl netting).
In the winter, your greenhouse may need extra heating, depending on the location and type of greenhouse, the total exposed area outside, and the needed indoor temperature. A home heating system is usually not adequate for a greenhouse. Heating systems can be fueled by gas, electricity, wood or oil. Heat can be distributed in several methods, such as by force with hot air or radiant heat, or run by hot water and steam. Methods such as a circuit electric heater or small gas or oil heaters installed in the wall can also be employed. Although greenhouses can be heated by solar power, it is not usually economical and requires a lot of separate space.
Prepare the soil for flower, produce or plant seeds. Fill flats with potting soil, and sow the seeds according to their planting depths and spacing on the package instructions. It is smart to group seeds together that have similar growing requirements, such as water or sunlight, to make caring for them more efficient.
Place the seeded flat so it is sitting in a 1-inch layer of water (such as in a larger flat or large sink). Once the water is sucked up through the drainage holes, you can remove the flat from the water source. This will hydrate the seeds.
Place the flats in an area of the greenhouse where the seeds will receive the necessary amount of sunlight (on average they need about six hours of sunlight per day). Make sure to evenly space flats so they receive proper air circulation. Water the flats once the top soil is dry to the touch. Installing a drip irrigation system can make it much easier to water your plants, especially if you have large crops.
Transplant the seedlings when they are about 3 inches tall to larger planter pots. Weed out any seedlings that appear weaker than the others or are dead.
Fill the planter pots with the prepared soil and indent a hole with your fingers for each seedling. Carefully tug up the seedlings from the flat and put one in each hole in the new pots. Water right after transplanting, and continue to provide full sun. From here on out, the amount of water, sun or fertilizer that each plant needs depends on the specific variety.