A greenhouse is a structure made mostly of glass or plastic where humidity and temperature can be controlled for the purpose of cultivating or protecting plants. The solar energy is absorbed by the plants and soil, and the warmed air is retained in the building by the roof and walls. Ventilation is an important component in the successful working of a greenhouse and serves four major purposes within the greenhouse.
Personal or Commercial Use
The first thing to decide is how the greenhouse will be used and will it be year round or seasonal use. The use, budget and room available for the building, will determine the size of the structure. If the greenhouse is for personal use, a small structure, around 80 to 100 square feet, will be sufficient. If the greenhouse is for commercial use, the size will depend on the amount of vegetation to be processed.
One thing to keep in mind is that some cities and towns will tax a greenhouse over a certain square footage at a commercial rate, even if the greenhouse is for personal use. A greenhouse over a certain size has commercial potential.
There may be zoning considerations if the greenhouse is also over a certain size and type. Before undertaking a greenhouse project, check with the local building and zoning department for the rules and regulations governing the construction and maintenance of a greenhouse. Ask for a copy of the written regulations, and not just rely on a verbal report from a clerk or zoning official.
If you are not sure if greenhouse planting is for you, start small, and leave room for expansion. You may find as you greenhouse along and find ways to utilize your greenhouse, you will expand the number of plants you want to handle.
Siting your greenhouse
Site your greenhouse to maximize sunlight. An optimum exposure is to locate the greenhouse in a south or southeast exposure. The long wall should have the southern exposure and the greenhouse should be twice as long as wide. Do not locate your greenhouse in the shadow of evergreen trees as they will block the winter sunlight and that is an important consideration if the greenhouse will be used all year long.
It is essential to provide positive drainage. That is, the rain water will drain away from the greenhouse to prevent flooding the structure. That includes the rain water coming off the roof. If the greenhouse has gutters, empty the gutters into a rain barrel and recycle the water. If the structure does not have gutters, consider adding a one foot wide by one foot deep crushed stone strip around the perimeter of the greenhouse to capture runoff.
It will be necessary to have access to water, or it will be necessary to fill and carry jugs of water to the plants for watering. If the greenhouse is close to the residential house, a garden hose may be run from an outdoor hose bib to the greenhouse or a small water line can be tapped off the house supply line and trenched to the greenhouse.
Electricity is another consideration for heat and lighting purposes. A separate metered line can be extended from the house to the greenhouse. Utilities extended to the greenhouse should be performed by the proper licensed contractor. The city or town may require inspection of such utilities upon completion.
Greenhouses should be at least 30 feet away from trees, but if the greenhouse will be built closer than 30 feet to deciduous trees and 15 feet away from hedges, it may be necessary to trim or cut the trees back to maximize sunlight to the greenhouse. Part of the greenhouse maintenance plan will be to keep the surrounding vegetation trimmed. A hedge or a row of trees may also serve as a wind break for the greenhouse. Excessive wind can be detrimental to the structure as well as cause fluctuating temperature in the greenhouse.
Colleen Kelley - I have been a freelance writer since 2000. I write, edit and publish newsletters for four non profit organizations and several ...
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