(March 29) Most consumers have at least heard of greenhouse produce, and many associate the name with tomatoes that are bigger, redder and juicier than the conventional kind. Few, however, have a real understanding of the greenhouse process and how it produces those luscious vegetables.
Here’s a quick review of the process that might help you answer some of the questions you get from your customers.
- Greenhouses can be made of glass or plastic, and there’s a similar structure called a shade house that’s made of cloth.
- There is no cut-and-dried definition of a greenhouse, and the terms “greenhouse” and “hothouse” often are used interchangeably.
- Most greenhouse growers prefer biological controls, such as beneficial insects, rather than pesticides to control pests.
- In state-of-the-art greenhouses, plants are nourished through a computer-controlled drip irrigation process that doles out just the right amount of nutrients. Temperature and humidity also are controlled by computers.
- Although the investment per acre for greenhouses can top $500,000, which accounts for the higher prices grower-shippers must charge, yields can be significantly greater than those of field-grown crops.
— Glass greenhouses are most prevalent in areas where temperatures are moderate and sunlight can be limited. They’re usually well-suited for tomatoes.
— Plastic structures work best where temperatures are hot and days are characterized by lots of sunshine. They’re well-suited for growing cucumbers.
— Shade houses are ideal for areas that need only minimal protection from the elements. They keep out pests and reduce wind damage, and they can have sides that roll up to provide ventilation and control humidity.
— However, many consider a true greenhouse to be a glass or plastic facility that has heating and, sometimes, cooling systems, and where produce is hydroponically grown in a soil-free medium, like rock wool.
— A hothouse has been defined as a similar structure that does not have heating or cooling systems and where product is grown in soil.