I think everyone who has a garden would benefit from having a rain barrel–I have four in my yard (three catching rain off the house and one from the garage). There are two main reasons I think everyone should have at least one; the first is that rainwater is free and tap water isn’t. Why pay for water from the city if you don’t have to? Secondly, rainwater is actually better for plants. Tap water has been treated with chlorine which isn’t good for your plants, and most has additives like fluoride that your plants don’t need. Tap water comes out of the tap cold–rainwater in a barrel is air temperature, and is therefore less of a shock for plants (this is especially important for seedlings). Additionally, from an environmental and ethical perspective, it’s a real waste to use potable water for irrigating your garden.
I will admit that while I try to use my rain barrels most of the time I’m not perfect—a lack of rain to fill the barrels or a lack of my own time to water mean I sometimes do use a watering wand and hose attached to a tap. I make the best choices I can. If I need to use watering cans and the barrels are dry I fill them from the tap and then try to let them sit for half an hour or more so that at least the chlorine can evaporate. This is my year-round practice for indoor plants.
If you don’t have a rain barrel and are thinking about getting one I recommend getting the largest one you can fit on your property. Then you just need a way to get water in and a way to get water out.
Getting water in
To fill the barrels from my downspout I’ve tried three styles of downspout diverters and my favourite is the splitter my contractor installed. It’s an upside down y, with a sliding lever that lets me switch from having water directed into the top of the barrel or to the left, to a downspout that spills water out onto the ground.
My understanding is that these splitters are available through eavestrough/downspout specialists and likely online—I haven’t seen them at any of my local hardware stores.
I purchased my least favourite diverter,manufactured by a popular garden supply company, at a big box store. The diverter is installed by cutting a piece out of your existing downspout and inserting the device in between the pieces. When fully assembled, rainwater is supposed to come down the downspout, hit a panel inside the diverter and shoot sideways out of a hose and into your rain barrel. Unfortunately, there seems to be a flaw in the design. Unless I jam a piece of wood in the device to make the inner panel fit more securely I don’t get any water flowing into the barrel. It’s certainly the slickest looking diverter I have but is the least effective.
In noticed during Garden Walk Buffalo that the Buffalo Sewer Authority provides rain barrels to citizens that seem to have some version of a sideways diverter, but it must works a lot better than my aftermarket product, as those barrels seemed to be full and well used.
The simplest way to get water into a rain barrel is just to have a downspout that ends just above a rain barrel. Water pours out the downspout and directly into an opening in the top of the rain barrel.
This works great in season but then one has to figure out what to do with all that water that comes pouring out during the winter (whether that water is melted snow and ice off the roof, or actual rain). I can’t keep my rain barrels full during the winter as they would freeze and crack open. I have one direct downspout like this, off the back of my garage. It doesn’t really matter where the water goes in winter there so I usually just turn the rain barrel upside down and let the water pour onto the overturned barrel and then splatter onto the ground.
Before we renovated I had a diverter like this on the back of the house. I didn’t want water spilling next to the foundation during the winter so I had a long set of big PVC pipes that I’d have to hook up to the downspout every fall, diverting water away from the house and into the back garden. Then I’d have to disassemble it in the spring. It was a bit of a pain.
Most rain barrels will have an overflow hose near the top. This is, of course, necessary for any sealed up barrel. For open top barrels, or barrels with just a screen over the top, water will just overflow and spill over the edges. That wouldn’t be a good idea for barrels located near the foundation of your house, unless you want a swimming pool in your basement.
Getting water out
Getting water from the rain barrel is either done through a spout at the bottom of the barrel or through an opening at the top. I find it easiest to get water out of my barrel that has a lid that lifts off—I just dunk my watering can in to fill it.
The ones with a spout at the bottom are good if you plan to hook them up to a hose or if you can get the whole barrel elevated high enough so that a watering can fits under the spigot. A spigot at the bottom of the barrel does require more bending from the gardener. I have seen rain barrels for sale that have the spigot placed a third or even halfway up the barrel—these aren’t very practical since you’d never be able to get at the water that’s below the level of the spigot. Someone didn’t think those designs through all the way.
Cover up, or at least use a stick
Whatever style of rain barrel you get you will want to make sure that the point where the water goes in is covered with a screen as open rain barrels, left to sit, can be a breeding ground for mosquito larvae. Having standing water on your property is actually illegal in some cities, including mine. If you’re using the barrel every day or two you’ll disturb the water enough that mosquitoes can’t breed—only you know how much you’ll use yours and what is right for your garden. I will point out that a screen also keeps rodents, raccoons and other critters from falling in and drowning.
If you don’t want a cover on your barrel I highly recommend that you do put a big stick in the barrel, reaching from the bottom of the barrel to at least the rim, so that any critter that might find its way in, looking for a drink, can get back out. You don’t want your garden to be the site of a drowning (and believe me, it does happen). I keep sticks in all of my watering cans for this same reason.