Greenhouse Irrigation and Explanation of Processes

Greenhouse Irrigation

Greenhouse plants have many different variables to contribute to their growth. One of the most important variables is water. Some crops need water continuously depending on plant species, size, temperature and atmospheric conditions.  Other types of plants do not. Inside a greenhouse, rain is impossible to occur, but the effects can recreated for the plants. Three type of water systems exist for greenhouse irrigation. These include drip irrigation system, sub-irrigation and overhead irrigation.

Drip and trickle irrigation is the most common type of irrigation. This method is used on farms as well as inside greenhouses. To begin, plastic tubing is used to water individual potter plants, or containers. It can be expensive to install depending on the area that needs to be watered.  Most drip systems use small diameter tubing, and filtered water to avoid damage to the foliage and the spreading of plant diseases.  Some benefits of this system are the capacity to conserve water, and the ability to deliver the water directly. Drip and trickle systems also prevents weed, moss and water loss.


Sub-irrigation systems water the vegetation under the ground.  Two types of sub-irrigation exist for greenhouses. These are ebb-and-flow, are trough. Ebb-and-flow use bench- mounted pots that are filled and then drained. Trough systems have water flowed in a sloping manner towards the pots.  In these methods, water is sent to the plant roots via a capillary action. Roots are penetrated with water directly from below instead of watering above.

Lastly, overhead irrigation is another way to keep plants hydrated. This system is not a misting system, but a sprinkler system.  The spray heads sprinklers are what determines the water rate, the size of the water, and the direction of the water. Fixed spray heads are used for small areas while rotating heavy are used for larger areas. The types of systems described above are all ways irrigation can occur.