Everything you need to know about keeping your garden alive and thriving in the heat. Topics include choosing drought tolerant plants, providing shade and windbreaks for veggies, storing water in tanks and in the soil, using mulch and compost to retain water and drip irrigation.
© Very Edible Gardens PTY LTD
Tanks – how big?
Garden beds – how much water?
Soil
Swales
Mains water
Source: Melbourne Water.
Irrigation
Greywater
There are two basic ways you can go:
- Low-tech, unfiltered, 'passive' greywater systems can be very cheap and have relatively low embodied energy and materials – these are the solution we usually favour. Shower water has the disadvantage of uneven distribution and can only water down hill plants in passive systems. For laundry we can use the washing machine pump to more evenly distribute, and can water plants up to about the height of the top of the washing machine. Greywater from these passive systems needs to be released into mulch-filled pits.
- Commercial systems by comparison, include filters, storage tanks and a pump. They generally require more maintenance than a well designed 'passive' system, and perhaps ironically, are subject to more regulations. Because they include pumps, the water can be distributed up slopes. Because they include filters, purple greywater dripline can be used which makes for very even distribution.
For laundry water alone, probably the best approach is the 'Laundry to Landscape' method outlined by US greywater guru Art Ludwig here: http://www.oasisdesign.net/greywater/laundry/
It uses the washing machine pump (without placing extra load on it) and an even and difficult-to-clog-up distribution system.
All of these systems use pits or trenches in the ground filled usually with a course non-fibrous mulch. The mulch will eventually rot down and become compost and need to be replaced every couple of years, so you can also use scoria which won't rot. If using scoria, you should put a layer of geotextile fabric on top of it and finish with crushed rock or some other surface that is nice to walk on.
The depth of the pit depends on the depth of your topsoil. You don't want the pits to be dug into heavy clays, where water will sit and stagnate. If you have no topsoil at all or very heavy clay soils, pits may not be appropriate at all.
Greywater regulations
Untreated greywater (reuse)
Untreated greywater from the bath, shower and clothes washing machine can be bucketed or diverted to water lawns and gardens, as a temporary supply of water during dry weather.
Diversion and bucketing of untreated greywater does not require a council ‘septic tank’ permit. However, to protect public health and the environment, untreated greywater should be reused in accordance with the most recent version of EPA Publication 884, Greywater use around the home, and not stored for longer than 24 hours.
Choosing laundry and shower products
What to plant
Relatively drought hardy fruit and veggies:
Veggies: Eggplant, Capsicum, Pumpkin, Zuccini, Basil, mediterranean herbs, to lesser extent Tomatoes, corn handle heat and days without water. Other things such as beans struggle. Consider perrenials like rhubarb, sorrel, artichokes etc for deeper rooted crops.
Trees: Peaches, Nectarines, other stonefruit. Pomegranates. Feijoa (survive but fruit better with water). Mulberry. Figs. Grapges. (Apples ok but not so great with full exposure to hot sun. Tropical stuff like avocados don't deal so well with hot sun.)
Innovative ideas
Aquaponics: organic hydroponics with fish in the mix. The most water efficient from of gardening but high on the materials input and engineering.
Save water in the home
Books
Create an Oasis with Greywater by Art Ludwig. US book but very good at home DIY solutions. The guru of greywater.
Harvesting Rainwater by Brad Lancaster. (2 volumes) Great ideas for captureing and directing rainwater where you want it with plumbing and simple DIY hand dug earthworks.