Gardeners use a lot of water, especially during the summer months when local rains slow to a trickle right when our lawns, flowers and vegetables need moisture the most.

And so we turn on the tap, and we water, water everywhere, using drinking water for everything we like to do outdoors, even washing off dirty tools.

Conservationists and green-living advocates are asking: Do we really need to be using drinking water on our ornamental landscapes?

There is a green solution: Install a rain barrel and harvest some rainwater this summer.

If you haven’t jumped on the rain-barrel bandwagon yet, Friday, which is Earth Day, might be a good time to get motivated.

Part of your home rain-harvesting system is already in place: your roof

Every inch of rain that falls on a 1,500-square-foot roof can provide about 900 gallons of free water, more than 30,000 gallons in Everett in an average year.

You just need somewhere to put it.

Because the average rain barrel holds only 50 to 75 gallons, you’ll have to install rain barrels near numerous downspouts to reclaim even a small percentage of the rain that falls on your property.

Fortunately, rain barrels are available in a variety of styles, including basic 50-gallon plastic barrels outfitted with basic hardware for about $35. There also are more aesthetically pleasing models designed to look like urns, whiskey barrels, even outdoor storage bins.

Flat-backed rain barrels help you save space as do collapsible varieties you can use seasonally. Extra-large models can hold up to 300 gallons. And wooden types are available if you want to avoid buying plastic.

Some come with top covers that can be planted with your favorite flowers.

You can even make your own rain barrel with kits that contain all the key parts.

If space is bountiful near your home, you can connect numerous barrels together for a much larger water supply.

Here are some tips about rain barrels.

Don’t drink the water: Collected rainwater is only as clean as your roof and gutters, where birds and animals may drop their waste. Use it with caution for watering some vegetables, but it is best used on ornamental plants and lawns. Avoid overhead irrigation of food crops when using rain barrel water, especially leafy greens. Always wash garden vegetables with tap water before eating them.

Know your roof: Roofing materials are sometimes treated with chemicals to fight rot and other problems. Moss-killing products, including zinc strips and zinc or copper-based moss killer, can leach into roof runoff and can affect plants and animals.

Direct the overflow: Rain barrels tend to fill quickly, even during light rain. Be sure your barrel has an overflow outlet and a tube or hose to divert excess water away from your house.

Cover it: To prevent mosquitoes from using the barrel to breed, cover any openings with fine mesh.

Raise it up: Build a raised platform from cinder blocks and place your rain barrel on top. This give you more room to fit a watering can beneath the spigot.

Secure: A full 50-gallon rain barrel can weigh more than 400 pounds. Find a sturdy, level site for your barrel. Strap it to the house with metal straps, especially if it is raised.

Rinse: Clean your barrel at the end of each season and scrub off any algae growth.

Check for clogs: Make sure intakes and overflows are not blocked with debris. Downspout diverters can easily be clogged with leaves if they don’t have built-in filters.

Prevent ice damage: If the temperature is predicted to drop below 32 degrees for several days, drain the barrels and disconnect them from the downspouts. Reconnect them when the cold snap is over.