(Note: This is Part 3 in a series. For more info on this topic be sure to check out Part 1 and Part 2).
If your problem is not too much rain, but too little, again we can look to nature for solutions. In nature you don’t see lush tropical plants trying to grow in the desert. Rather, the flora follows the climate, with plants growing only as full and lush as the local water sources allow. We can learn from nature’s wisdom by adapting our gardens to suit our climate and by making good use of every raindrop the sky gives us! We can mimic the water cycle by carefully conserving and re-using our water supplies. We can mimic deserts and prairies by landscaping with drought-tolerant native species rather than “thirsty” turfgrass and ornamentals. And for those of us that are really ambitious, we can mimic the way that forest landscapes hold onto rain by utilizing techniques like Hugelkultur and swales.
1. Water Conservation.
Like I mentioned in Part Two, rain barrels are one highly recommended way to capture rainwater. You can stretch this water out a lot farther with efficient irrigation systems utilizing drip tubing or micro-sprayers. This sort of set-up can also save you money on your water and electricity bills. Combine your rain barrel and irrigation system with a solar-powered pump for a completely off-the-grid watering solution! Wayside’s irrigation systems use water much more efficiently than sprinklers or watering wands, delivering moisture right to the plant’s roots so none is lost to evaporation or runoff.
A Water-Wise Micro-Sprayer Kit
Another way to conserve water is to re-use grey water to irrigate your lawn and garden. Grey water is the water coming from your sinks, showers, and laundry machines—basically all of your washwater with the exception of toilet water, which is classified as “black water”. I am sure most of us would rather not mess with toilet water, anyway! I have neither the space nor the expertise to explain the logistics of a greywater capture system, but I highly recommend that you look into it. Greywater re-use can irrigate most if not all of your garden, shrubs, and trees for free, and the food particles and bacteria from the kitchen sink actually improve the soil. Even if you don’t have the time or money to install a full-blown greywater capture system, one quick and easy thing you can do is capture dishwater by simply putting a large bowl in the sink before you wash dishes, then tossing it onto the flower bed once you are done. Whenever you make pasta or vegetables, that strained water gets full of lots of delicious nutrients that your plants would love!
2. Xeriscaping.
If you choose the right plants for your property, it is amazing how much you can cut your water needs. Consider replacing your thirsty grasses and ornamentals with Xeric native species that require less water to thrive and can tolerate longer periods of drought. The lack of fresh water in Colorado, Arizona, and much of California has made Xeriescaping a popular trend in the West. With the right garden design, folks are finding that they can cut their water usage drastically and improve their garden’s appeal.
Wayside has a huge selection of beautiful drought tolerant plants to choose from. Check with your local extension service to see which species are native to your region and most likely to thrive in your garden.
Red Creeping Thyme stands up to drought and foot traffic!
For the garden, plants like Bee Balm, Butterfly Flower, Miscanthus, Coneflower, and Aster are all highly recommended Xeric species that can stay gorgeous with very little water.
For the yard, consider replacing walkways with stepping stones or gravel pathways. These never need watered! The more of your square footage you fill up with stone, the less water your yard will require. Just be sure to use gravel or permeable pavers for your patios, walkways, and driveways rather than concrete or blacktop. A solid slab stops water and leaves it sitting exposed to be lost to evaporation, but a permeable surface lets water trickle in and moisten the soil. If you grow xeric perennials along your walkway, your plants will gladly absorb the stone’s share of the rain.
For those spots where you really feel that you want turf, like the places where your children run or your dogs play, consider replacing your grass with more drought tolerant and beautiful groundcovers that can still take some abuse, like Bugleweed, Dwarf Mondo Grass, Stonecrop, or Creeping Thyme.
3. Improving Soil Moisture Retention
But even drought-tolerant species have their limits. If you want your garden to stay lush, beautiful, and productive, you can’t let the soil turn into a cracked, sandy wasteland. You might be tempted to break out the sprinkler, but that is only a band-aid fix. Looking to nature for inspiration, we see that there are better long-term ways of improving the soil so that it holds onto rain much better. (Note: It’s a good idea to get to know your soil quality first before you begin amending.)
The Shortcut to Improving Your Soil
The first thing you should do to condition your soil is add lots and lots of organic material. In forests a thick layer of leaf litter keeps plant roots shaded and moist, and all the half-composted leaves and twigs in the soil hold onto moisture even a few inches down. We can make our own soil hold onto moisture just as well by amending it with plenty of compost before planting and by adding plenty of mulch after planting. You can also add a bit of Soil Moist, and the polymer granules will swell many times their size and hold on to water for weeks, or you can use a larger volume of the all natural alternative, Coconut Coir, which will also condition the soil wonderfully.
Coconut Coir holds onto moisture like a sponge.
Now, if you really want to mimic the great moisture-retentive soil of the forest, the most important thing you need to add is rotting wood. This may not sound like a good thing to be tossing into your garden beds, but think about it: when you go out into the woods in the middle of a drought, where do you find moisture? Even when the leaf litter is thoroughly dry and all the twigs underfoot are going snap, crackle, and pop, there is still one place that stays moist: inside of logs! Trees are so good at holding moisture that even for a long time after their death the rotting logs stay nice and dark and moist inside. And because of these dark, moist conditions, worms, fungus, and micro-organisms have a welcoming environment to live and breed in, which advances the decomposition further. It’s one of those self-perpetuating cycles that Mother Nature built into the system, because she is smart like that.
The idea of using rotting wood underneath of garden beds comes from Germany, where it is called Hugelkultur (“Hill Culture”). Apparently German farmers started using their cleared brush as a base for their raised garden beds, basically for convenience, and then they found that the base of decomposing wood helped the plants stay fertilized and hydrated for years!
Hugelkultur Garden Bed by Jon Roberts from Austin TX, USA (Garden, 12 Apr 2012 Uploaded by zellfaze) [CC-BY-SA-2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons.
Even if your Hugelkultur bed takes a while to get established, it is worth it, because once they get going they can help feed and water your plants for up to 20 or 30 years! One side benefit of this method is that it requires no tilling. As the wood decomposes, the sticks and logs shift and develop air pockets. This helps keep the soil nice and aerated, but the downside is that over time your garden bed develops holes. To fix these holes, all you have to do is poke around with a shovel to find the collapsed spots, and then fill these in with good compost. Another benefit of a Hugelkultur bed is that decomposition creates heat, which helps to keep your plants’ roots warm, extending the season of growing substantially. The first few seasons will be exceptionally long for you, after which the pile will gradually cool down.
Hugelkultur is an incredibly effective and completely renewable way of holding on to all the water that soaks into your soil. But what about those spots where water never seems to soak in, like slopes and hills where the water flows right past? For these spots you want to dig swales.
A swale is simply a water-retention ditch, but the key is in how you dig it. When digging your swale, you want to run it on contour: that is, you want to make sure you are staying parallel to the slope of the hill rather than perpendicular to the slope, pointing up- or down-hill. If your swale goes perpendicular to the slope, you will see the uphill part of the swale drying out while the downhill part holds all the water. For your swale to hold water evenly, it needs to run right along the contour of the hill. To make sure your swale follows the contour, you want to build a simple A-frame and use it to mark a contour line. Stack all the soil that you dig up on the down-hill side of the swale to serve as a berm, stopping the water’s downhill momentum and letting it soak into the ground, creating a naturally-moist soil to grow plants on.
Swales work especially well when the berms are done Hugelkultur-style, with a lot of rotting wood added at the base of the berm. You can see this in practice in the picture above. By combining these two techniques, you increase your landscape’s ability to utilize rainwater drastically.
Sepp Holzer, widely regarded as the most brilliant permaculture farmer alive, has used these two techniques in combination to rejuvenate badly-eroded sites, turning flat patches of nearly-barren desert into hilly, productive forests gardens. Sepp’s teachings can (and do) fill books and books, but at the core of his method is always his reverence for water and his desire to manage it effectively, storing it and delivering it to plants without wasting a drop. Water is life, after all. The key to nurturing life in your own garden is first and foremost to manage your water wisely!
*Update: Lately I have heard some Permaculture experts offering good arguments against Hugelkultur Swales, namely that the rotten wood is a poor engineering choice for holding back water because it tends to float up out of the soil and/or break apart, releasing your stored water. I must caution you, therefore, not to use this method on steep hills or large areas that will be holding back substantial amounts of water. For the average-sized, gently-sloped back yard, though, your swale should hold just fine.