How to Harvest Rain Water

When a drought strikes you will thank yourself for having a store of rain water harvested.

By Doug Oster


Summer 2012

Rain Water Harvesting

Harvested rain water can be a lifesaver during a drought.

Photo by Fotolia/dplett

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Q: What can I do to help improve my results during a dry season? We deal with drought occasionally and still want to grow a great garden. — Mandy in California 

A: There’s nothing more worrisome in the garden than long stretches without rain. The first tip is to collect as much rainwater with rain barrels attached to gutters. One decent rain can provide hundreds of gallons of water for the garden. There are lots of plans online showing how to build your own, or purchase one ready-made from a garden supplier. If making your own, be sure to use only food-grade barrels — never anything that once contained chemicals.

When placing plants in the garden or landscape leave a slight depression at the base of the plant to hold rainwater. This is easy to do in the vegetable garden and I also like to sink a 4- to 6-inch pot into the soil and when I water, the pot is filled up, slowly dispersing the water.

Mulch, mulch and more mulch will help keep the soil evenly moist and also has the benefit of reducing fungal diseases. 

Improve the soil with lots of compost. Good garden soil is well drained, but also able to retain moisture. Choose plants that are drought-tolerant like succulents and other tough perennials. 

There’s a group of gardeners experimenting with dry farming: the 19th century practice of growing crops with only what nature provides for water. There’s lots of information online about techniques and successful varieties to grow. 

When you water, do it smartly and remember plants only need an average of one inch of rain per week. The best time to water is early in the morning. It gets the plants ready for the day and allows the foliage to dry off, reducing the chance of fungal diseases.

Water at the base of the plant instead of using overhead watering. This allows the plant to use most of the water and avoids loss by evaporation. Drip irrigation is great way to water. Hoses strategically placed under mulch run on a timer and literally drip water to the roots of the plants where it’s most needed.

Place shade cloth over cool-weather plants so they don’t need as much water to be happy.

When watering, it’s better to soak the ground under plants to promote deep root growth. One good long watering a week is better than five shallow applications.