Water is essential to plant life and is a critical input to nursery crop production. For plants, water is used in temperature regulation, as a carrier for nutrients and plant hormones, and is the hydraulic force behind growth. Water is taken up by plant roots and is lost to the environment through the stomates and the leaf cuticle. A water deficit can negatively affect plant growth, plant health and the amount of time needed to grow a crop to a marketable size.
Irrigation can shorten the production period for field nursery crops and increase quality, which has a positive impact on nursery profitability. Because the nursery industry has shifted from primarily field-produced crops to container-produced crops, the need for irrigation is increasing. Over 75 percent of nursery crop value (gross farm gate) in 17 of the major nursery producing states is currently grown in containers (USDA 2009). Container nursery production is not possible without the use of irrigation.