Irrigation options for High Tunnels

One of the most important factors to consider when adding a high tunnel or managing an existing one is irrigation. It might not seem obvious, especially when you live in a moist and humid climate with plenty of annual rainfall, but the growing conditions created within an enclosed plastic or glass greenhouse structure are essentially the same as an irrigated desert – sunny, hot and dry with only a controlled source of water.

The simplest and most economical solution is to use a watering can or hose with a hand-held sprinkler attachment to water manually, and while this option may work well within a small high tunnel or even during an emergency situation, this method is quite cumbersome, time-consuming and sometimes challenging to gauge if and when you have watered sufficiently. How do you know if you have watered enough? The general rule of thumb is one inch per week during the growing season, whether it is supplied by actual rainfall or irrigation. And there is a common old-timer’s expression in New England that asks, “Did the moisture meet?” In other words, did the moisture that was applied go deep enough into the soil to meet the lower layer where the soil still holds moisture? If the answer is no, then it is typically more effective and much more efficient to supply water through various irrigation options. Some of the most popular and common approaches include overhead sprinkler irrigation systems and surface drip irrigation systems, both for their ease of installation, dependability, automation, and efficient water use. Combining the two options together in one high tunnel can also be an effective solution for many growers, especially if following four-season methods and growing crops year round. The simplest and lowest cost solution is a portable hose and sprinkler head system but it does involve more monitoring and manual repositioning of the sprinkler head in order to provide even coverage and avoid over-watering.

Click her for a more detailed description of the various options at rimolgreenhouses.com