Summer garden hints and water conservation.
Each summer brings us here in the lucky corner of the lucky country closer to the real environmental situation of the planet.The global scale of water misuse and mismanagement is beyond our individual scope to fix, however there are local strategies that can help in our own gardens while improving the quality of life in your neighbourhood by increasing soil moisture for trees and other deep-rooted perennial plants thereby allowing more evapotranspiration for cooling the air, while providing shade over roads, pavements and small children.
Most of us learnt about the hydrological (water) cycle at school, but industry and wasteful everyday use by an expanding population have changed the balance by removing forests, using up groundwater and polluting what's left.
One of the hardest things to get on this planet is clean fresh water and yet most is still used for wasteful lawns, car washing and other unimportant jobs where quite clean water goes down the drain or is polluted and added to the drinking water supply, rivers or oceans.
With water restrictions in place we need to look at the way we use water and try to learn how to be more conservative in our use. The Perth metro region is full of those who want their gardens to thrive as they would in a place with regular year round rain, however, our gardening styles need to change and we need to adopt dryland strategies to keep ahead of the hot, dry summer. 1. Use water more than once.
Permaculture encourages the multiple use of water, ie use it more than once and if possible it should be just as clean (or cleaner) when it leaves the land than when it got there. Ideally it shouldn't leave the property at all, but be reused, recycled or retained on site or in the ground.
Huge amounts of water get barely used as it rushes by in the shower, or rinses washing up. Some is barely dirty, let alone needing to be chemically 'cleaned' again with a nasty mix of chemicals, including even more chlorine now that dams are low and the water's not so clean.
2. Collecting rainwater.
Collecting rainwater from the roof of a building isn't too bad if the first lot of water is allowed to clean the roof. This allows for bird droppings, leaves, insects etc to wash off the water collecting area. Collected water can be used to keep gardens alive, if you don't want to drink it.
Rainwater collected for drinking should have a bag of limestone in it to make the water hard (alkaline), reducing uptake of heavy metals and reducing heart attack incidence, which occurs more in those who drink soft (acid) water. If everyone had water tanks in their yards, even just for watering the garden, a huge amount of water would be saved and we'd be drinking less chemicals.
3. Improve and increase water infiltration into the ground.
Improving and increasing water infiltration into the ground can mean the difference between trees, natives and other perennials surviving on a few big drinks during summer or not. Water run-off is a big problem for some gardens, especially on bare and/or sloping ground.
Terracing or making berms or swales can reduce the loss of water. A swale is a banked area which runs perpendicular to the slope and acts as a catchment area for water and dust, dirt, leaves, seeds or other organic matter that may get blown into it. They can be any size depending on the given area, from a bowl shape in the ground around a tree to long cross slope trenches a metre or more wide on larger properties. These dug trenches have the removed soil placed to the lower side of the shallow trench and perennial plants, especially trees, planted on the low side of them. The trees hold the banks into place as they grow and are fed by the debris that falls in, whilst casting shade on the trench and helping the bank's other plant species to establish. Any water that is caught gets slowed right down and it actually gets to soak in around the tree providing water where none may have been recoverable previously. (see the book: Water for Every Farm by PA Yeomans, or their website: www.keyline.com.au for more on water harvesting on a larger scale).
Gutters and drains steal a lot of the water that would be best left to soak into the ground. Water from downpipes and gutters can be directed to areas of the garden where berms have been built, helping your water-wise garden become established with less help.
Most rain is quickly swept away by the 1000's of kilometres of roads and concreted areas to pollute the ocean with runoff, oil and heavy metals; large woody plants are better able to survive these pollutants than the ocean can, and protect the soil while they do it. Urban forestry isn't practiced enough, where firwood could be grown from run off, in compensation basins, drains, etc. In country areas and roadsides, road runoff can be directed to bermed, terraced or pitted areas where rehabilitation of bush can occur. Once a few tough trees have established, the shade they make helps other species to grow. 4. Using biological processes to clean water.
People with large amounts of space could even consider building a series of ponds in their backyard to clean water they have used. They range from really dirty used water in the first pond, then as it gets filtered through different grades of rocks and plants, the water can end up clean again, and more biologically active than it started. 5. Mulching.
*Mulching should be recognized as one of the larger initial costs in establishing a permaculture - Bill Mollison (Permaculture co-founder)
*Deep mulching is important in open areas between plants, keeping moisture in the ground, rather than letting it evaporate.
It's easy to gather large amounts of carbon and nitrogen rich materials from the side of the road (though not as easy now that everything gets put into bins).Bulky materials are also often cheap to get but can be hard to transport.
Big piles of green waste quickly break down to rich brown soil full of worms, (with some watering), which all too soon gets 'cooked' away by UV if more isn't added or plants are not used to cover the soil. It is a good idea, if you want a lot of mulch, to grow some in the form of trees (especially Acacia's), shrubs and herbs that can be cut for rough mulch.
6. Windbreaks.
Windbreaks have many uses as shade, shelter, mulch producer, to slow winds and to cool the dessicating easterlies. Soft leafy plants soon become crispy if they need to bear the easterly unprotected, so tougher plants need to bear the brunt of the wind. A hedge of hardy herbs and shrubs can cool the air in your garden so other tastier species can be grown. As it getts drier, I believe we need more than ever to grow trees for shade, shelter and soil protection. How can anyone deny the relief you can feel sitting under a large leafy tree on a hot day?
DRYLANDS HOUSE
A few ideas for cheaply cooling a home. Solar passive design isn't something most people think about when building a house unfortunately, so retro-fitting can make a difference. Retro-fitting to me partly means planting more trees!!! They provide moist cool shade and stop the ground heating up. Internal courtyards shaded by lattice or trees.
Most effective if it is two or more storeys high and shaded by the building. Small shadecloth covered courtyards can be added to single storey houses. Middle Eastern cities have been built like this for centuries, each high wall shading the next, sunlight hitting the ground only when it is directly overhead. Fully-enclosed vine arbours with mulched floors and trickle irrigation.
These suit single storey dwellings. Arbours need to cover about 20 per cent of floor area to provide cool air, hanging houseplants aiding cooling, as does a shaded water tank.
Summer sun angles.
The modern trend for no eaves on houses not only reduces outdoor sitting areas (folk stay inside with the air conditioner on instead), but also allows summer sun straight into a lot more windows, warming the air inside. In summer the glass on windows facing west need shading on the outside with blinds or shutters so you don't create your very own private green house effect indoors.
Thick vines, evergreen trees or in a pinch, thick shadecloth can be used to stop the sun heating up walls. Vines are living insulators which can stop the low westerly sun from heating walls which then take the rest of the night to cool down. Deciduous trees planted to the north help keep the house cool.
By preventing bricks and tiles heating up and allowing winter's heat in when the leaves drop off. Shading all the exposed areas of a house can make a huge difference to the temperature indoors. Even though it's getting drier, we need more than ever to grow trees for shade, shelter and soil protection. How can anyone deny the relief you can feel sitting under a large leafy tree on a hot day? Vicki B.
