How to Harvest Rainwater to Water Your Garden

Water is one of the essential requirements for growing plants. Rain is the natural way plants receive this, but in most gardens, including raised beds, rain alone is not enough. Rain has an ironic habit of either giving too much or too little. In some areas, you may not get rain for a month at a time. The solution may appear obvious: turn on the faucet. However, there is another way. You can collect rainwater and store it for future use.

For every 2 inches of rainfall, your garden gets approximately ½ gallon of water for every square foot. This means that if you collected water from 2 inches of rain over a 10-foot by 10-foot space (or 100 feet squared), you would have 50 gallons of water.

How to Harvest Rainwater

The easiest way to collect rainwater is by using your roof. In a moderate precipitation, the average home will fill a 55-gallon container in two to three hours by only collecting water from one side of the house. This idea of conservation fits well with natural gardening, but any utility conscious individual may want to try it.

The easiest way to collect the water is to use your existing gutters to funnel the water to a collection device for rainwater. You may need to purchase a downspout converter that will allow you to collect the water as long as the storage device is empty. These devices will adjust the flow of the water so that any excess rain will follow the original exit path once the storage container is full. Without this feature, you may have water back up and overflow the gutter in heavy rains, which can lead to issues around your home. For example, an overflowing gutter could increase soil erosion around your house's foundation.

Storage Containers for Collecting Rainwater

You'll find many different rainwater storage containers on the market. While size is one of the biggest differences, with a small container only holding a few gallons and a large one holding over 500 gallons, containers may have different features to consider. The most basic containers have a lid that helps keep the rainwater clean. The lid allows you to access the water and dip out of it when you want. For a little more money, you can buy a container with a valve on the bottom. This lets you attach the garden hose right to the collection device.

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Making Your Own Water Harvesting System

Gardeners can make all the components they need for a rain harvesting system from materials at the hardware store or even from around your house. This can be a great way to think outside the box. For a rain diverter (the piece that sends the rain from the gutter to the container), you can use PVC pipe. Remove the downspout and attach your PVC pipe directly to the gutter with one end. Make sure to use a large diameter pipe to keep the water from backing up. A filter at the top of the PVC pipe will help keep debris out of your water containers.

For the container, find something that is non-corrosive. The most popular material for a storage device is a large plastic container. Choose one that has a tight-sealing lid. You can connect the PVC pipe to the container by drilling a hole in the top of the lid.

You can also add a valve at the bottom of the container in order to attach a hose for watering. Before attaching the valve, you can heat the plastic around the hole with a hair dryer to make a better seal as you tighten the valve. The pressure from the water at the top of the container will force the water through the garden hose at a surprising rate.

If you wish to connect another container to the main unit, drill a hole into the side of the unit about 2 to 3 inches from the top. The second (and subsequent containers) must be either lower in elevation or shorter than the previous unit. From the hole in the side of the first unit, attach a pipe to the top of the next unit. As water rises to the hole in the first unit, it will flow over to the second.

If you don't like the idea of using plastic storage containers, you can find plenty of alternatives. With some creativity and design, your containers could become a piece of art. You can paint the containers or use decorative pieces to add to your backyard landscape. Large pieces of pottery can make great rain-holding vessels.

You can also hide most containers with bushes or a fence. Regardless of how you come by harvesting rainwater, you will have the benefits of pure water at an ambient temperature. Both things help to grow fast and strong plants instead of shocking their systems. Find more information about organic gardening at our DIY blog.