According to the 2017 Census of Agriculture, U.S. greenhouse vegetable farms more than doubled from 2012 (USDA 2019). Virginia fell within the top 10 states for acreage of vegetables and berry crops grown under protected culture. Protected culture includes greenhouses and structures like high tunnels. With close to two and a half million square feet devoted mostly to tomatoes, vegetables, herbs, and strawberries, the value of Virginia greenhouse sales in 2017 was over 31 million dollars! A lot of this increase in square footage was due to the addition of large operations coming into Virginia.

With the increasing number of controlled environment agriculture farms, Virginia Cooperative Extension is working closely with specialty crop growers to address the challenges of establishing and managing hydroponic greenhouse operations. Growers interested in producing food crops in controlled environments can use several different types of hydroponic systems. One of the most common types of hydroponic systems is called nutrient film technique (NFT).

One common type of hydroponic system is known as a media system and utilizes some type of containerized media to grow plants. This media or substrate is used primarily to anchor the plants while nutrient solution is delivered to the plants via sub-irrigation or top-irrigation. The terms media and substrate will be used interchangeably in this publication.

This factsheet is part of a series of seven factsheets targeting beginning farmers growing edible crops using hydroponic greenhouse systems. There are also five videos that are related to the factsheets and included in the numbering sequence.