Growing vegetables in a greenhouse can dramatically extend their growing season, as the warmth and humidity make it possible for plants to be more productive. Additionally, greenhouses with the right type of lighting and heating systems can produce vegetables year-round, which helps provide fresh, local food for the individuals who use or buy from the greenhouse. Extending the growing season of vegetables is an easy way to increase profits when using a greenhouse.
Reducing pests in a greenhouse is much simpler, since windows and doors can be left closed and it is easier to see and solve any problems more quickly with the application of pesticides. Most greenhouse vegetables are grown on raised tables, which puts them in a visible position. Pest problems can sometimes be caused by the greenhouse, because the humidity can promote mildew. Investing in a greenhouse with a good fan system helps farmers avoid this.
As with an outdoor crop, greenhouse vegetables need to be irrigated. According to The University of Florida Extension, using nutrient film techniques--a series of tubes placed in the bottom of the tables to provide water--can supply ample water, but can also drown young crops if not controlled. Monitoring the amount of water going into the tables is essential for preventing crop damage. Both flooding and drought can kill vegetable plants before they become productive.
Greenhouses can range in size from industrial-size buildings to small, home-owned greenhouses constructed by hand. The size of the greenhouse depends on the needs of individual farmers or collective farming groups, as well as the types of vegetables they intend to produce. A smaller crop can be grown in a smaller space, whereas vegetables that grow on vines or need vertical space, may require a bigger greenhouse.
Producing vegetables in a greenhouse requires a great deal of effort on the part of the farmers to maintain both the building and the plants. According to The University of Georgia Cooperative Extension, every 4,000 square feet will need anywhere from 25 to 30 hours of maintenance for successful production. Although growing vegetables in a greenhouse can be a very profitable experience, it does require an investment of time and effort.