How To Collect Rainwater and Use It for Your Plants?


Collecting rainwater for use in your home garden is an eco-friendly idea that will benefit your plants and the environment. With the current water crisis in many parts of the world, practicing water conservation is good now and for future generations.

Save money and eat healthier by collecting and using rainwater on your garden plants.

Rainwater is free and will help reduce your water usage and bill at home. In addition, rainwater is easy to collect and will enable you to keep garden plants well hydrated during the hot summer months. Plus, rainwater is classified as ‘soft’ water, and it’s free of all chemicals, making it the perfect water to use on garden plants. Any substances, including those in water that are purchased from municipalities, that go into growing food will end up in your body.

How Much Rainwater Can You Collect?

Let’s look at how much water you can collect in an area with an average rainfall each year. For example, if the site receives 10-inches of rain in spring and summer, a typical house roof will yield around 8,160 gallons of rainwater in a year. That’s a tremendous amount of water that gets wasted if it’s not collected and recycled into the garden.

Even a half-inch of rain on a small roof that is 1,000 square feet can yield up to 300 gallons of water. Three hundred gallons of water is enough to keep a small garden well hydrated for 2-3 weeks during the summer.

How to Harvest Rain Water?

Collecting or harvesting rainwater is an easy process. All you need is a few rain barrels. Place the rain barrels in suitable locations, and the rain will do all the work for you.



Most homes have gutters that capture and channel the excess water off the roof. In addition, several downspouts will allow the rainwater to drain out of the trenches and away from home. By placing a rain barrel under each downspout to catch the rainwater, you will be collecting the water for future use.

Gutters and downspouts can easily be installed by a professional or a DIY project. In the process of collecting rainwater, this would be the most significant one-time investment you would need to make. However, the money saved on your home water bill, plus increased food production from the garden, will more than compensate for this initial investment. In addition, using a downspout divertes would make it easier to direct rainwater into your storage tank.

Storage Tank


Rainwater cisterns are have been around for centuries and are gaining popularity again as storage tanks for rainwater. These cisterns are made up of either plastic or concrete. Their holding capacity ranges from hundreds to thousands of gallons of water.

Using a downspout divertes makes it easy to direct rainwater from your roof into a storage tank. Other types of diverters are also used to run roofs or groundwater into cisterns to be utilized later.

Any outdoor structure, like a garage, barn, or greenhouse, should have gutters installed and downspouts to collect and store rainwater.

Lid and a Debris Screen

A screen to filter debris is needed for all rainwater catchment systems to keep the water clean. Fallen leaves, twigs, and other small debris from the roof float into the gutter and down through the downspouts. If a filter is in place on top of the rain barrel or cistern, it will prevent the debris from entering it and keep the water clean. However, debris will also build up in the bottom of the catchment system and clog up the spouts used to access the rainwater.

A removable wire mesh screen is enough to filter out most debris. You can either attach this mesh to the top of the barrel or tank or at the bottom of the downspout.
A fitted lid is also essential to keep children and pets safe and prevent mosquitoes from laying eggs in the standing water. Use mosquito control rings that can be purchased from any garden supply center to prevent mosquito eggs from hatching in your collected rainwater.

Water Distribution Device

After the gutters, downspouts, and rain barrels or cistern is in place, it’s time to install a system to distribute the water that will be collected.

If you use barrels, you will need a standard fixture installed in the barrels near the bottom. A water hose can be attached to the spigot or a bucket placed under the tap to drain the water from the barrels.

A short hose can be used to siphon the water out, or a bucket can be used to dip the water out.

How Much Rainwater Do You Need for Your Garden?

Here is a simple method to calculate the amount of water your garden will need to thrive during the summer. First, calculate the average amount of water used per day in your garden. Next, consider how many days of rain there is in your area during the summer.

Calculate daily water usage and multiply it by the days your area usually doesn’t receive rain to discover how much rainwater you will need to collect and store. For example, if you use 20 gallons per day and it rains once a week, you will need 20-gallons of water for 6-days which equals 120 gallons a week. Multiply that by the number of weeks in a typical growing season in your area, and that’s how much water you will need for the entire gardening season.

Tips to Use Rainwater Wisely for Plants.

Even though you will have plenty of water to keep garden plants well hydrated, you still want to use the water wisely. Here are some tips for wise watering.

  • Water plants early morning or late evening, so a minimal amount of water is lost through evaporation. Plants absorb water better in the early morning hours too.
  • Apply water at the soil level and keep the plant foliage dry. Wet leaves can lead to plant disease and pest infestation. Leaving water on plant leaves can also cause the plants to become sunburned as the water droplets can magnify the intensity of the sun’s rays.
  • Only water plants when the top of the soil is dry or when the plant leaves begin to droop. Overwatering plants can cause them to drown, so only water is needed.

The Last Words

Rainwater is a special gift for garden plants grown outdoors or indoors. Harvesting rainwater and using it for keeping garden plants well hydrated is an eco-friendly method to reduce the amount of water you use. In addition, plants regularly watered with rainwater thrive better because the water is soft and contains no chemicals.

Collecting and using rainwater is easy and affordable. A few essential pieces of equipment and a little investment of time and money can make a home catchment system for rainwater. In addition, your garden plants will be healthier and more productive when rainwater is used to keep them hydrated.