Did You Know? Collecting Rainwater for Your Garden

Collecting rainwater for your garden…it’s sounds pretty simple doesn’t it? Well, it can as simple or as complex as you make it with a little planning. One-third of all of the water used in the United States goes to irrigation. Now I don’t mean just the water that you use to water your lawn and garden; much of the irrigation water goes to agricultural production. And that’s important, right? Well, you could grow some of your own food to reduce your dependence on industrial agriculture but that’s not the topic of today’s post.

So how can you collect rainwater for your garden? There are all sorts of ways but let’s start with the simplest: the rain barrel. Rain barrels are an excellent way to capture some of the rainwater that is generated from your roof during a storm or shower. They’re scaleable as you can add bunches of them together so that you can keep collecting rainwater well beyond the typical 55 gallons that each holds. They can be attractive if you’re the artsy type…boy I wish was!

free water for your garden
Photo courtesy of www.prwd.org


So how much rainwater can a typical roof capture in a single rain storm? What’s your guess? 100 gallons? 1000 gallons? 10,000 gallons? Pull out your calculator (or your cell phone) and let’s do the math. My small rancher has a typical A-frame roof and each side of the roof is approximately 60′ x 20′. That’s 2400 square feet of roof surface area. Let’s say that we receive 1″ of rain. One inch of rain falling on one square foot of roof yields 0.6 gallons of water. So….2400 x 0.6 = 1440 gallons of rainwater. You would need 26 rain barrels just to catch the rain from a single 1″ rain event. In Virginia, we receive around 43″ of rainfall each year. That’s 61,920 gallons of water that you could be catching from your roof each year. That’s a lot of free water for your garden!

So what can you do if you don’t have enough room at your house for 1126 rain barrels (that’s how many you would need to collect all 61,920 gallons)? There are underground cisterns that can be installed to capture your roof runoff.

free water for your garden
Photo courtesy of www.chesapeakestormwater.net


These are systems that you need do some serious math for as well as figure out how you’re going to get all of that rainwater out of the tank. The beauty of rain barrels is that you use gravity to get the water out of the barrel and into your garden. With cistern based systems, you have to use a pump to get the water to your plants. But the cost of the water that is saved by capturing your roof runoff can more than offset the cost of operating the pump.

free water for your gardenWhat are some other ways to capture free rainwater for your garden if you don’t have access to an underground cistern? How about the tanks that everyone seems to have for sale these days? Check your local Craigslist for great deals. What about 5 gallon buckets to start with? Put one under each downspout to catch rainwater that you can use to water your garden. How about a kiddie pool? You can pick them up for under $10 at your local big box store. Any rainwater that you can catch is water that you don’t have to buy or pull from the depths of the ground to provide your plants with moisture.

What ideas have you used to capture rainwater for your garden? Leave me a comment below or e-mail me at stacey@midatlanticgardening.com. If you enjoy being part of the Mid-Atlantic Gardening community, join our e-mail list (upper right hand corner of this page), become a fan on Facebook and follow me at Twitter. Happy gardening!

Friday Free For All: Using Water Wisely

Well, it’s happening already. The Mid-Atlantic gardening region is dry. Granted, we have 1″-2″ of rain expected this weekend but the rain has been pretty negligible in central Virginia since the middle of March. I hope that this isn’t a sign of things to come this summer. My mind has been churning about how much water we use. Not just my family or community but as a nation…as a world. Water is a renewable resource but that doesn’t mean that we can use it with reckless abandon. Let’s delve deeper to look at how we can use water more wisely in our gardens.

  1. Hugelkultur – if you’ve been reading my posts for a while, you know that I am big fan of hugelkultur. It just makes sense…use wood that nature has provided for us to help plants through the dry spells. Check out the link for more information if you’re unfamiliar with the practice of hugelkultur.
  2. Reduce your plants dependence on irrigation – while it is vitally important to make sure that newly transplanted plants are watered until they can get their roots in the ground, it is generally not necessary to water them for the rest of their lives. We had an extreme drought in 2010 here in central Virginia and emergency water restrictions were put in place; those restrictions meant that you couldn’t water…at all. One of the reservoirs that feed our public water supply, Lake Chesdin, was all but reduced to a pond. It was truly an amazing sight to see. During that drought, guess how many times I watered, even before the emergency water restrictions were in place. Zero. Zip. Nada. I am of the mindset that my plants will either live or die trying. I don’t have the desire or time to water them regularly. So do you know what they do to compensate for my lack of interest? They send their roots further into the ground to search for their own water. For the record, I didn’t lose one plant during the drought either.

    using water wisely

    Lake Chesdin 2010 Photo courtesy of Richard MacDonald

  3. Water wisely – for those newly transplanted plants, get creative with your watering. For trees, water slowly and deeply to make sure that the rootball is being wet thoroughly. You can accomplish this in several ways. One way is by using a treegator. These are available in either donut shapes for multi-stemmed trees or upright bags that zip shut around the tree trunk. You fill them with water and the water drips out slowly and wets the rootball. If you want to make your own cheap tree gator, get a few 5-gallon buckets and drill tiny holes in the bottom. Set them around the base of the tree and fill them with water. The water will trickle out slowly and water the rootball. You can also just let the hose run at a trickle for a half hour or so at the base of the tree.using water wisely
  4. Mulch – mulching your garden will help to reduce evaporation and regulate soil temperature, both of which will reduce your plants need for water. Mulch should be applied 2″-4″ thick. If you apply it thicker, you will reduce the amount of oxygen that is penetrating into the soil and that will impair the plants’ root growth. For heaven’s sake, don’t end up with mulch volcanoes around your trees!
  5. Apply compost – this is such an important part of using water wisely. By adding compost, you are improving soil structure. By improving your soil structure, your sandy soil is able to hold more moisture and your clay soil begins to open up to allow water in. Adding compost is the magic ingredient that makes all of the other items we discussed today possible.


So what will you do in your garden to use water wisely this summer? There are many other ways to reduce your water usage and I’d love to hear what you are doing. Leave me a comment below or e-mail me at stacey@midatlanticgardening.com. Happy Friday and happy gardening!