Starting a commercial greenhouse is a serious undertaking that should only be attempted by someone who understands the complexities involved. Establishing a commercial greenhouse business can easily take up to a year before you can begin to sell your goods, due to the time needed to construct the greenhouse and grow the vegetables. Additionally, extensive knowledge in horticulture is a must.
Learn the requirements for becoming a certified organic farmer. To become certified, you must submit an application with detailed information about the type of operation you run and the products being grown. Additionally, you'll need to provide documentation on any substances used on your land within the last three years and an organic system plan (OSP). The OSP will include all substances used, monitoring practices, record keeping and practices undertaken to ensure that organic products don't mix with non-approved substances. Contact your state's department of agriculture to find a local certifying agent, who will then inspect your business.
Enrol in a horticulture course, unless you have previous experience working in a greenhouse. You'll need to learn about organic fertilisation, the best soil for your vegetables, how to test soil, irrigation, water and plant needs and how to safely manage pests. Contact local universities, colleges, garden supply stores, cooperatives and farms to find training courses in your area.
Have an idea of the types of vegetables you want to produce and the space needed to grow them. Learn the optimal light, water and heat requirements for each. Review Chapter 7, section 205.105 of the National Organic Program document for allowed and prohibited substances and ingredients that can be used in your produce.
Select a location for your commercial greenhouse. Consider access to water, the properties of the water, the history of the soil, drainage characteristics and the proximity to suppliers and customers. At a minimum, your commercial business will require at least two greenhouses, one for beginning crops and one for mature crops. Depending on the types of vegetables you will grow, you may need more. Your location may easily exceed an acre in size.
Purchase your commercial greenhouses. Popular commercial models include quonset huts, ridged or furrowed models, both of which may be curved or arched. Barn-style greenhouses are another popular choice due to their straight walls, which allow for more use of space. Coverings may be made of glass, fibreglass or polythene, depending on your light needs.
Select an irrigation, ventilation and heating system. Irrigation systems include drip system, misters, and water sensors. Heating systems include portable heaters, hot water pipes, wired in electrical heat or solar heating. Portable heaters are easy and practical, but may not be desirable for a large greenhouse. Instead, look for an environmental computer system that can regulate the heating, light, cooling, watering, humidity and carbon dioxide. Purchase a soil sterilisation system, circulation fans, drip systems, shelving, benches, grow lights, foggers and shades.
Find organic seed suppliers in your area. (See Resources.)