(diagram lifted from SAGE)
There are a number of advantages to gardening this way. First and foremost, it conserves water. Out of any collection of plants in residential outdoor landscaping, garden plants tend to require the most water. In hot Austin summers (and springs... and falls...), garden plants typically need to be watered every day which means losses to evaporation every day from inefficient application. A wicking garden waters from underneath, so losses to evaporation are minimized. Furthermore, the plants use what they need, and the wicking replaces what they used and nothing more. The gardens also act as rainwater catchments. If a big rain comes, the excess infiltrating water refills the reservoir below. The claim is that a wicking garden uses 50 percent less water than conventional watering techniques.
Another advantage is that wicking gardens don't have to be tended to everyday: the water reservoir waters the plants. Depending on the size of your reservoir, you can go days and days (and perhaps weeks) without worrying about your plants (great if you're going on vacation or are [ahem] just plain lazy). Every once in awhile you check the water level in the reservoir and top it off if needed.
Yet another advantage is that since the plants get exactly the water they need exactly when they need it, the growing conditions are ideal, so the plants go gangbusters.
What is there not to like? Nothing, really, although these gardens are a bit more effort to set up.
It turns out Austin has a number of advocates of wicking gardens, and there are ample resources online:
- LoveATX (a local take on wicking)
- Instructables (a wicking worm bed)
- Food Is Free (quick video demo from Austin gardening activists)
- YNN (local news channel)
- resilience (nice collection of wicked wicking info)
We are already planning on using livestock troughs for our garden:
so this wicking business makes absolute perfect sense for us. In fact, watering this way may prevent us from having to install the second rainwater tank.