After a long hot summer, in which most of our gardens suffered tremendously, it’s time to rethink our plant watering. We probably all know by now that we should have drip irrigation instead of overhead sprayers. Drip irrigation under mulch saves water by delivering the water exactly where it is needed. There is less runoff and evaporation. But there are many traditional low-technology watering techniques that are used in permaculture, which can also help you make your property more water efficient.
Wicking beds
Wicking beds or pots are well known by now and popular for a reason. Wicking pots are self-watering containers that use capillary action to supply water to plants as needed. They consist of a large container with a reservoir of water at the bottom, separated from the potting soil by a layer of fabric or a wick. This setup allows plants to draw water from the reservoir as needed, promoting consistent moisture levels and reducing water wastage. They are easy to make and can be used for various types of plants, from vegetables to flowers.
Newly planted wicking bed at Ayla Community Garden
Ollas
Ollas are unglazed clay or terracotta pots buried in the garden soil to provide slow, efficient watering. They work by gradually releasing water from the porous walls of the pot into the surrounding soil, directly hydrating plant roots. Ollas help conserve water by reducing evaporation and surface runoff while promoting deep root growth and healthy plant development. They come in different sizes, with larger ollas obviously being more efficient.
You can see small ollas in planter pots in action here.
Medium and small olla before being buried
Watering tubes
Watering tubes are sustainable solutions for efficiently watering trees, especially in arid or drought-prone areas. These tubes are usually made of durable materials like PVC or recycled plastic and are buried near the tree's root zone. They work by allowing water to slowly seep out directly to the roots, encouraging deep watering and minimizing water loss due to evaporation or runoff. Watering tubes are adjustable, allowing you to control the water flow rate based on the tree's needs and environmental conditions. This method promotes healthier root systems, reduces water waste, and can be a cost-effective and environmentally friendly approach to tree irrigation.
Watering tubes work best when installed when the tree is planted and still developing roots. They encourage trees to send their roots down deep to where the water is, making them drought hardier in the long run. Trying to dig them in next to established trees might damage their roots and will not be as effective as the root system is already developed.
Soil Improvement and Earthworks
Storing rainwater in the soil for longer is the most efficient way to make the most out of the rain that does fall. To do that, we have to improve our soil so it can absorb and hold water. Organic matter can hold up to twice its own weight in water, so increasing the amount of organic matter can increase water holding capacity. In sandy soils, the addition of clay has an even greater effect, as clay holds up to six times its own weight in water.
Once you have improved your soil, shaping the ground to slow down water and preventing water from running off can help the absorption of water. Sunken beds, swales or rain gardens are all methods of directing the water into flat trenches or lower-lying areas where the water can slowly sink in to re-hydrate the soil. This can be done on a large scale on rural properties or as small versions on urban blocks. We’re overjoyed to see councils taking up this technique more and more, for example to direct water from car parks or roundabouts into sunken native gardens.
Mulch
Lastly, don’t forget to keep the water in the soil by mulching to make the most of your irrigation. Mulch for efficient water retention is best when it is coarser, for example mixed wood chip mulch. Finer straw mulches can soak up the water, creating a barrier that prevents the water from soaking into the soil.
In summary, we need to find watering techniques here in dry Western Australia that are sustainable and efficient. From a permaculture perspective, we always favour low-tech option if available. Complicated reticulation systems need constant maintenance and many things can go wrong with them. Ollas and wicking beds are simple, efficient techniques which generally don't create any problems.