Botanica Atlanta | Landscape Design, Construction & Maintenance

Rain falls from the sky and onto landscapes of the Southeast on more than one-hundred days each year. That averages out to almost one out of every three days that your garden receives precipitation, and I find that most landscapes fail to reach their grand potential on these days. Rainfall is something ephemeral, natural, and beautiful. More importantly, rain is something that is absolutely critical to your garden’s soil health and your plants’ survival.

In the civilized world of man - where cold is blocked by synthetic-lined jackets, heat is doused by air conditioning systems, and the sun’s rays are blocked by rooftops and polarized glass - we tend to associate the occurrence of rain with feelings of discomfort and inconvenience.

Image: Bruno Hautzenberger

To plants, however, rainfall is quite the opposite. When the first plump, wet drop of a coming storm falls onto a plant’s leaf, it is a moment to celebrate. As the raindrop’s mile-long freefall ends abruptly by crashing into a leaf, the shaking of that leaf might as well be a ringing dinner bell. Precipitation provides a plant with sustenance, and an ample rainstorm ensures a plant’s survival for days, if not weeks.

So how can you properly honor a rain event in your garden? Unfortunately, the typical solution that is employed on most properties involves collecting the stormwater into drains and quickly channeling this fluid into underground pipes that spit it directly into the local storm sewer. Though this default strategy does accomplish one necessary task - the protection of your house from flooding - the solution lacks creativity and it certainly far from natural. Failing to wisely control and harness the sometimes violent accumulation and movement of rainwater can lead to the erosion of your garden’s soil and can have a larger scale detrimental impact on the ecological health of your local streams and rivers.

Images: Sam Valentine, Jeff Curtis, Avis Adams, and Thiago Souto

Artistic downspouts and rain-chains are excellent ways to delineate the path of water as it flows from your roof to your landscape.

Collecting this water for use, also known as “rainwater harvesting,” is one excellent strategy for conscientiously dealing with precipitation on your property, but harvesting your fallen rain is more than just a courtesy to your local environment. These rain catchment systems - which can range from a simple rain barrel connected to one of your existing downspouts to complex underground cisterns and irrigation systems - can help your garden survive through periods of drought and even government-enforced watering bans. (For more detailed information on rain water harvesting, study up on earlier Botanica Atlanta posts categorized under Water Management, including “Planning for a Dry Summer” and “Harvesting Rain Water”.)

Images: Lady Bird Johnson Wildflower Center and Local Ecology

I advise a combined strategy of exhibiting rainwater and harvesting it in your garden, as exemplified by the Lady Bird Johnson Wildflower Center. A research unit of the University of Texas at Austin, the Center is a pioneering agency in a region where rainfall is only a fraction of that in the Southeast. The Wildflower Center surely practices what they preach, and their facilities include a water harvesting system that collects 10,200 gallons of useful water for each inch of rainfall. Furthermore, one of the architectural centerpieces of their garden is an aqueduct that is cleverly designed to double as a vine-covered arbor. An example such as this one, along with historic design precedents like Spanish runnel irrigation, offers plenty of design inspiration for collecting rainwater and delivering it to needy plants, while at the same time visually demarcating the journey that this precious liquid takes through your landscape.

If you have a 2,000 square-foot single story home in northern Georgia, your rooftop will intercept more than 62,000 gallons of water in an average year. What do you plan to do with yours? With so many options available, I advise that you not just let it go down the drain.

Author: Sam Valentine, BLA, LEED AP