12 Things To Consider When Selecting Greenhouse Site - Utilities, Roads & North-South Orientation

7. Utilities – Availability of utilities should include telephone service, three-phase electricity and fuel for heating and carbon dioxide generation.*Note that, when compared to propane, electricity or fuel oil, natural gas is the most economical heating energy source.

8. Roads – Need access to good roads to transport the “product”. Good roads close to a large population center, or to a brokerage center aids wholesale and retail marketing.

9. North-South Orientation – The greenhouse should be oriented north-south, AND the
plant rows within the greenhouse should be oriented north-south. *If oriented north-south, the greenhouse structure itself will not cast consistent shadows on any one area of the plants throughout the day. *If oriented north-south, the plant rows will receive equal light throughout the day. If oriented east-west the south most rows (in the northern hemisphere) will shade the rows to the north.

12 Thing To Consider When Selecting Greenhouse Site - Elevation & Microclimate

3. Elevation – will effect the summer maximum and the winter minimum temperatures.
Choosing an appropriate elevation will minimize heating costs in the winter and cooling costs in the summer. Example: In Arizona tomato production is most economical between 4000 and
5000 feet (1220m-1520m). Below 4000 feet cooling costs in summer will be more whereas above 5000 feet heating costs in the winter will be more. Lower elevations might be suitable for peppers or cucumbers.

4. Microclimate - Factors which falls in microclimate considerations:

• Latitude – Unless the global climate changes drastically, sea level at the poles will be colder than sea level in the tropics… latitude makes a difference!
• Large bodies of water – will tend to moderate the temperature (e.g., coastal areas tend to have smaller day/night temperature differences than inland areas)
• Trees, mountains or other obstructions – may cast shadows on the greenhouse, especially in the morning or afternoon hours. Mountains can also effect wind and/or storm patterns.
• Clouds and fog – Note that certain areas (e.g., on the lee side of certain mountain ranges, or near coastal regions) may develop clouds or fog during certain times of the day or year that will reduce potential sunlight.
• High Wind Areas – High winds can “suck” heat away from the greenhouse structure and therefore increase the heating energy demands.
• Blowing dust/sand – High winds can “kick up dust or sand”, especially in desert regions, which can damage some greenhouse glazings.
• Snow – The weight of heavy, wet snow on a greenhouse could crush it. However, high winds in snow areas can also blow snow up against the greenhouse structure (snow drifts) and cause damage to it. This danger can be reduced by using windbreaks (trees, snow fences, etc.).