While walking with a blueberry grower a few weeks back, we stopped at a young blueberry shrub with dramatic brown blotches dotting the leaves. The big concern is always disease, but this time, it was an easier answer. There hadn’t been a drop of rain in three weeks and it was all anything could do to stay green and upright. Like many plants, the poor blueberries were shriveling under drought stress. The good news is that while it would be two more weeks before we saw any rain, the grower was putting together their drip irrigation.
To make it through our southern summers, irrigation is key for both growers and home gardeners. There are many ways to water plants and each has its pros and cons. We should also have three goals in mind when we water: watering at key times to meet water requirements, avoid wasting water, and limiting the spread and development of disease caused by wet foliage.
Whether you use a watering can or a hose, we’ve all hand watered a time or two. Hand watering is inexpensive even if it is time intensive. It’s a great way to water each plant exactly and individually, even if the amount of water put out can vary from person to person. If done carefully, you can avoid wetting the leaves and place the water directly at the roots.
Overhead irrigation, such as impact sprinklers, is an inexpensive foray into automatic irrigation. Low cost and easy to put together, it’s a number one choice for many homeowners. The downside, however, is that you will more than likely get the foliage wet and you will probably end up watering a much bigger area than you intended to.
A drip system is the next step up and can be more expensive than an overhead sprinkler system. What you lose in cost you gain in direct irrigation of the roots. This irrigation system keeps the leaves dry and avoids watering more than necessary.
Regardless of which system you go with aim to supplement rainfall to meet about one inch of water a week. Putting out over an inch at a time can lead to runoff or water loss to evaporation. Also be mindful of key times of development where you will want to make sure your plants get watered for sure: fruit and flower development in squash, cucumbers, and tomatoes, and pod filling for peas and beans. The right amount of water at the right time means higher quality produce with a better taste.
Selena McKoy is Horticulture Agent for North Carolina Cooperative Extension in Harnett County.