As Minnesota gardeners continue to adapt during the drought of 2021, it’s natural to think about ways to conserve and reuse water for our gardens. Rain gardens are a great way to keep water on your property. Another option is to collect rainwater from roofs using a rain barrel.
Why Get a Rain Barrel?
There are many benefits to collecting rainwater from your roof and storing it for later use. Once the barrel is set up, the water costs nothing. The water is not chlorinated and has the pH of (duh) rain unlike water that comes from the hose and may have a higher pH that is harder on plants. It reduces your personal water consumption and also gives you a supply of water for gardens during city-imposed watering bans or restrictions. It also helps keep water away from your foundation by storing it in the barrel.
Besides the benefits for you as a gardener, it has many benefits for our lakes, streams and ecosystems. Collecting rainwater keeps it where it falls, preventing excess flow into storm sewers, lakes and rivers. It also keeps pollutants from spreading into those natural resources.
Rain barrels are available from a variety of hardware and garden suppliers. You can also recycle a food-grade barrel to store rainwater. (See the video below from This Old House about how to install one for about $40.) If you’d like to make and install your own rain barrel, our friends at Metro Blooms hold classes on this topic several times a year.
To install the barrel, you will need a diverter on your downspouts to redirect the water to the barrel. You will also need a spigot at the bottom of the barrel. It works best to put the barrel on a platform so it’s a foot or so off the ground. This allows you to put a watering can under the spigot. You can also add a hose to bring the water to your containers or gardens. The rain barrel will also need some kind of overflow system for when it rains more than the barrel can hold.
Most barrels hold 55 to 60 gallons of water. This is large enough to collect the rain from a 1 inch rainstorm draining a 100 square foot area. (For more on calculations, check this website.) If you want to collect a lot of water for your garden, you can hook up multiple barrels or installing rain barrels on several downspouts.
What about Winter?
You’ll need to empty your rain barrel and re-direct water back to your downspout when winter comes. Many of the attachments people use to hook in a rain barrel have a simple way to re-direct the downspout flow. In late fall, drain your barrel. Leave the spigot open so that water that may condense inside the barrel has a way to flow out. Make sure the top of the barrel is covered and tight to prevent rodents from falling into the barrel. You should also clean out any filters on the top of the barrel of leaves and other debris.
Can You Use Rain Barrel Water on Vegetable Gardens?
Because water in rain barrels is coming off of roofs, which may contain chemicals or fecal matter from birds and other critters, using rain barrel water on vegetable gardens is not 100 percent safe. The University of Minnesota Extension recommends you should NOT use water from a rain barrel on any part of a plant that you may eat. So, it would be fine to use rain barrel water to water the base of your tomato plants or to water a fruit tree at its roots. But because it is not tested for safety (unlike water from your hose), you should not use rain barrel water on greens, strawberries or root crops. Of course, whether the water comes from a hose or a rain barrel, you should give all your vegetables a good washing in a pan of cool water before eating.
Rain barrel water is the perfect solution, however, for ornamental plants and trees, which desperately need water now.