Greenhouses are perfect for year-round plants and vegetables but of course greenhouses do not have contact with rainfall. Every greenhouse needs some kind of watering system, from the most basic to the most advanced.
The simplest of greenhouse irrigation systems is the hand-held can. It is also quite effective in that you can get the water to go wherever it is needed especially with difficult-to-reach areas of soil. While the watering can is lightweight and easy to use, it quickly becomes impractical as the size of the greenhouse and the plants within it increase. Generally, the watering can is best used on the smallest of greenhouses.
Once again, the hose is one of the more simple and least expensive ways to water plants in a greenhouse environment. The problem lies in getting the water where it is needed most. With hoses, it is the leaves that tend to get the majority of the moisture rather than the soil and roots. For smaller greenhouses, however, the hose can be very effective. For larger greenhouses, it can soon become impractical.
A mister system works by releasing small droplets of water over the tops of the plants. This keeps the leaves cool while still providing all the water that is needed. The water is released intermittently throughout the day but the system is not without its problems.
Temperature regulation and dryness can be an issue, as these units are left open a great deal of the time. It is also essential that the equipment is in good working order at all times. The small holes on the nozzle can frequently become clogged if not checked and cleaned regularly.
Similar to the garden hose, a seep hose has thousands of tiny holes that allow water to drain from the line. These are generally buried about 2 to 3 inches below the soil, allowing the water to come out along the length of the hose.
Seep hoses are known for their efficiency. The can generate a regular supply of water to the plants and lose very little to evaporation. They also reduce the chances of mold and mildew building up as a seep hose will not overwater the leaves. This is good for root formation, as roots search downward rather than sideways for their water requirements.
The choice of greenhouse watering system is going to depend largely on the size of the greenhouse and the types of plants being grown. Those with a simple greenhouse and household vegetables will likely get away with a watering can or hose. If you have larger aspirations or commercial businesses, look into something automated that can meet your needs.