Unplug This Blog!
RSS Feeds
May 16, 2009
Rainwater, but no municipal water, for my garden this summer
Posted by Nola Poirier
I'm giving myself a challenge this summer and I hope I can entice you to join me. I'm not going to use any (yes, I said any) municipal water in my garden this year.
Okay, I'm being a bit cheeky, I'm not on a municipal water system. It's a community water supply. But I'm not going to use that, or well water, either. Whether you're growing herbs and flowers in containers on an apartment balcony, or, like me, have an acre of land planted in food, medicine and insect attracting flowers, it's possible to do it without using drinking water. And I don't just mean I can have my garden survive, I think I can have it thrive without adding water from the tap.
How my plants will survive
I'm not just going to cut the plants off water, they would almost certainly die in the dry weather of summer. Instead, I have a fivefold plan to keep them healthy and moist for as long as possible. It includes building soil structure, planting densely, directing available water where I need it, developing microclimates, and rainwater harvesting.
None of these steps is difficult, they are all modelled on what happens in nature, and once you start getting the pieces in place, your work becomes greatly reduced. Not only do these methods keep you from having to constantly water, many of them reduce weeds and unwanted garden pests as well.
I'll go through some ideas for each of them, one at a time:
- Soil Structure. Having grown food in the Okanagan, El Salvador, inside my Volkswagon van home, and up and down the west coast, I have witnessed the truth in the adage that the best place to store water is in the soil. One foot of good soil can hold as much water as a three-inch deep lake of the same size. Good soil structure comes from plenty of organic matter. It can take a little time (or money) to build up soil to hold its full water-holding potential, but it's a constant progression. Some key ways are to add plenty of compost and to mulch deeply and often with organic matter. Soil structure is important whether you grow in gardens, fields, or containers.
- Dense Planting. There are very few plants we grow that need all the sunlight we get in our long summer days. Planting things closer together, in relationship so each gets the light it needs, will cut down on weeds, increase your garden's productivity, and help the soil retain moisture. Dense planting can mean planting more salad greens into each row, but it's even better if you diversify plants and cover more needs at once. Combine insect attractors, mulch plants, shade plants, and food into your gardens to keep it working as a system – and working for you.
One well-known example is the Native American Three Sisters planting: mounds of corn and beans surrounded by a vining squash. The corn provides a support for climbing beans, the beans fix nitrogen needed by all three plants, and the squash leaves shade the soil, keeping it moist.
Another example is growing something soft and leafy like comfrey around the perimeter of your garden beds, or under the drip line of fruit trees. The comfrey provides moisture retaining shade, and it pulls nutrients from deep in the soil. A few times a season, you can cut back the growth and let the leaves lie on the garden, providing nutritious, soil building, moisture-retaining mulch for the beds. - Directing Water. This can be as simple as moving a container plant (or a bucket) under a drip from the balcony above. Or it can involve building swales (water holding contours) into your land. In every case, look at where water gathers and flows (from your roof, ponds, depressions, ditches etc.), and think about how you can use that flow to put water where you want it.
As well as directing water, think about situating your plants to get the moisture they need. If a plant likes it wetter, plant it downslope (and yes, even your 'flat' yard has slope) from a water gathering depression. If it likes to be dry, put it up higher or on a raised bed. 
Devloping Microclimates. Some plants like it hot, and some scorch or bolt with too much sun. By developing microclimates, you can give each plant what it wants in a small area. One way I create microclimates is by planting small spiralling mound gardens for culinary and medicinal herbs. By building up instead of out, I have a shadowy side, a morning sun side, a hot, dry top, and a moister lower level all in one compact, easy to harvest garden. Some other ways to create microclimates are to add small piles of rocks in or near gardens for shade, windbreaks, and even to serve as homes for snakes and other helpful garden critters. You can also arrange your plants in ways that will provide shade, sun, moisture, and heat where it's needed. - Rainwater Harvesting. Finally, and importantly, cycling rainwater through our gardens before it flows off to the sea makes use of this incredible resource – and helps you appreciate rainy spring days. Rainwater barrels, cisterns, ponds, swales, and water catching plants are all great ways to capture this water for use in your garden. Use a few methods to maximize your water capture and ensure you have a water supply right where you need it.
Of course, I live on the Sunshine Coast where (despite the name) we get more precipitation than the Okanagan or Slocan or Cariboo, but in drier areas it's even more critical to design gardens to hold their moisture. And just as these methods apply to keeping water, many of the same strategies can help boggy areas as well.
Some ideas to consider when moisture levels get low:
- Put a basin in your sink when you wash dishes. Use a natural, biodegradable soap, and carry the used water out to plants. Note though, untreated grey water should never be used directly on plants you eat. Instead, put it on your fruit trees or shrubs, or your non edible insect attractors and shade plants. Or you can pour it into a swale where it will filter through the ground to the roots of plants.
- An especially great trick for arid areas, but one that will work well anywhere, is to use rock mulch. Surround plants with a couple of inches deep of small rocks (1 to 4 inches diameter). They will catch dew and filter it into the soil. As well, on hot days the heat flowing through the cool air pockets under the stones will trickle additional moisture to the ground below.
So here I go in my attempt to save water. It's my first summer on this land so I haven't yet built up my soil structure, or established useful perennials for shade and density, or installed rain barrels, but I am up for the challenge. Of course, I might fail and have to squeak out a few watering cans to keep things alive.
But even if I get close, I'm going to call it a success. However much rainwater your area receives, saving as much water as you can is critical. I hope you will join me in my challenge. You've heard of the 100 mile diet, well this is the 150 day water diet. Stay tuned and I'll try to keep you posted on my progress.
Some great resources for more information:
- (The New) Create an Oasis with Greywater by Art Ludwig (2007 – or any edition)
- Permaculture: A Designer's Manual (the book that inspired many a garden oasis) by Bill Mollison (1988).
- Blue Gold: World Water Wars, film ( 2008) (it's also a great book by Maude Barlow and Tony Clarke).
Nola Poirier is a freelance writer and key contributor to the bchydro.com Green Guides. She now works from a home on the Sunshine Coast.
