When deciding the best method of watering plants in a nursery, consider many variables including the number of plants that are being grown, type of plants, labor costs, setup expenses, maintenance and water-use efficiency. Often it is best to mix and match various types of watering systems according to the needs of individual species of plants that are being grown and their requirements.
For smaller-sized nurseries, watering each plant by hand is possible. This can take a long time and requires a lot of labor, which can get quite expensive. It also requires there to be a long hose or many different water spouts scattered evenly around the growing area. Long hoses can get tangled easily and may become a safety hazard when spread across pathways. The benefit of hand-watering is that each plant gets regular attention by an individual who can monitor any potential problems when they begin, such as disease, or plants that may be missed in an automated watering system.
Sprinklers are the cheapest automated or semi-automated watering systems for nurseries. They're also the easiest to install. For large nurseries, this is often the only feasible, cost-effective watering solution. The drawbacks of sprinklers is that they waste a lot of water. Much of the water does not get into containers or some plants get missed around the edges of the system. It also opens the door to potential pathogens from constantly damp leaves.
Sprinkler heads can be either rotating or fixed. You need more fixed position sprinkler heads to cover the same amount of area as the rotating types.
Capillary mats are water absorbing mats that are placed under the containers. Water is pumped into the mat and the soil in the containers slowly absorbs it from the bottom. These are becoming more popular because they use about 60 percent less water than sprinklers. The drawback is that salt and mineral deposits can build up in the container and burn the plant roots without regular flushing of the potting medium with clean water.
Spaghetti tubes are small tubes that slowly drip water into a plant container. Each container gets its own tube that is connected to a centralized network of pipes. This is a very efficient way of watering plants but may not be suitable for plants that like to dry out between watering. Very dry soil does not absorb the dripping water well and it tends to run out of the bottom of the pot without completely moistening the soil evenly.
Like spaghetti tubes, each container gets its own sprinkler head that waters the plant from the top, but still below the level of the foliage. Sprinkler heads can be bubblers that emit small amounts of water in bubbles, small mister heads or spikes that fit into the soil. These systems are highly effective but can be very costly to install in large nurseries. Usually these systems are reserved for hanging baskets where hand-watering is not practical, or for watering large containers.