Rain barrels are hot garden accessories. A rain barrel connected to a downspout lets you collect 50 gallons or so of free water every time it rains. It’s also the mark of an environmentally sensitive gardener. With a rain barrel, you’re conserving a precious resource and setting a good example at the same time.
You can’t count on a rain barrel to provide enough water for a big lawn, or to irrigate long rows of tomatoes or beans in a vegetable garden, but a barrel full of rainwater is enough to keep the plants on the porch watered and can give plenty of water to newly planted trees and shrubs. An attractive rain barrel by the porch makes you less likely to forget to attend to pots of flowers around the front door. As rain barrels have moved into the mainstream, designers have kept up with classy-looking models you'll be proud to put right out front.
When you are trying to figure out where to set up a rain barrel in the garden, some of the decisions have already been made for you. The barrel doesn’t just sit out there to collect the falling rain; it gathers it from an elevated, impervious surface — in other words, a roof. The natural place for a rain barrel is just under the eaves of the house, connected to a downspout. You might be tempted to put the rain barrel right beside an outdoor spigot, but it would be better to put it where you do not otherwise have easy access to water. Of course, it is important to check local codes and the rules of your local homeowner’s association before you settle on a spot for your rain barrel.
Most residential rain barrels are of modest size, holding up to about 55 gallons of water. An inch of rain on a typical 1,000-square-foot roof will channel more than 600 gallons of water into a home’s downspouts. A good rain will provide more than enough water to fill a barrel. Overflow valves direct excess water away from the house and keep the water from pooling up around the barrel. If the overflow can be directed into a low-lying area, this is a good place for a rain garden full of attractive plants that tolerate moist soil. Rain gardens allow the water to seep back into the soil instead of washing off into storm drainage systems.
A rain barrel full of water weighs more than 400 pounds, so give it a firm, level foundation. Raising a rain barrel a foot or so off the ground also makes it easier to get to the spigot (which is at the bottom of the barrel). A pad of cinder blocks or pavers will support a rain barrel nicely, or you could make a platform with two-by-four lumber and sturdy corner posts (several plans for platforms are available on the internet).
You can attach a hose to the rain barrel’s spigot, but your barrel will not have enough pressure to run a sprinkler. It’s easier to use the hose to fill a watering can (remember, a gallon of water weighs about 8 pounds) and carry the water to your plants.
If you live in an area with watering restrictions, rain barrels save the day. You can’t turn on a hose on no-water days, but as long as there is rain in your barrel, you can water to your heart’s content.
Rainwater is also better for your plants than treated municipal water — it contains none of the salts, minerals or chemicals that have to be added to city water, but it naturally contains nitrate, a form of nitrogen easily accessible to plants.
You'll definitely save some money on your water bill when you rely on a rain barrel as one source of water for your garden — but the investment you make in a rain barrel goes beyond money. When you make room for a barrel in your garden, you’re taking a stand for conservation and sustainability, protecting your local watershed by reducing storm-water runoff, and saving energy that would otherwise have been used to treat and pipe water to your garden. In a world of limited resources, it’s something to bank on.