Ran Pauker, Green Point, Nir Oz
I am grateful to the following for their valuable comments: Avigayil Heller,Ori Fragman-Sapir, Eitan Rosenberg, Bilha Givon, Debbie Lehrer, Dani Elmaliah, Hagit Tsioni, Hezy Mula, Haya Itiel, Yossi Zohar, Itshack Hel-Or, Israel galon, Michael Avishai, Michal Nahari, Nava Henig Sever, Nurit Hermon, Oded Yaffe, Puah Bar, Reuven Oren and Sarah Adar.
Acute scarcity of fresh water is becoming a worldwide problem and is far from being limited to arid areas. Yet everyone feels a natural longing for green gardens and surroundings – emblems of culture and civilization ¬– and for the serenity that green confers
Fortunately, one can create a water-wise and ecologically friendly desert oasis by obeying all ‘Ten Commandments for a Water-wise Ecogarden’ – after due adjustments for the particular conditions prevailing in the target garden, be it old or new.
Gene Likens recently (1992) defined ecology as follows:
Ecology is the scientific study of the processes influencing the distribution and abundance of organisms, the interactions among organisms, and the interactions between organisms and the transformation and flux of energy and matter.
The artificial environment of the garden – and most gardens involve the creation of such an environment – harbors all the processes found in an ecological system. That is why our approach must be ecological, the better to assure that the garden will be environmentally friendly and sustainable.
1. Design a sustainable garden
Planning is the key to success in creating a water-wise ecological garden that will be well suited to the climate and environment, the amount of water available, and maintenance possibilities (both physical and financial), and that will also meet the long-term expectations of the garden’s owner.
2. Study the soil
Information about the depth and the mechanical and chemical composition of the soil is crucial for deciding whether to try to improve water percolation, water holding capacity, and conditions around the roots (do they promote a deep and well developed root system? what of plant nutrients and aeration?) – and for deciding how to go about it. Knowledge of the mechanical composition is particularly important when soil from an outside source is to be placed on top of the existing soil.
3. Irrigate in accordance with the plant’s needs
• Supply measured amounts of water to each site or plot.
• Prepare an irrigation protocol specifying the amounts of water that should be supplied to every portion of each plot in accordance with the kind of plants being cultivated and their growth stage. Water amounts should also be adjusted to allow for differences in the plant’s position, the season, and soil type.
• Macro- and microclimatic conditions, nutrient application and various stresses – all these influence the plant’s water consumption. Assess the actual amount of water supplied to the plant by observing its ‘body language’ (external manifestations of the plant’s growth and behavior).
4. Use an efficient irrigation system
The irrigation system must be designed and operated in accordance with the basic principles listed in the previous 'commandment', and the water emitters (sprinklers, microsprinklers, drippers) should be chosen and planned accordingly. Even when water is applied according to a time schedule, precise measurement of actual versus planned water delivery must be enabled; this is the only way to detect errors of planning, faults in the pipe system (leaks), or incidents of plant stress.
5. Collect run-off
Both the topography and the infrastructure of the garden should be designed with a view to catching as much as possible of the surface water flow – rainwater, water running off impermeable surfaces, and condensation from air-conditioners – and storing it in the garden soil. In this way, instead of burdening the drainage system on its way to the sea, the run-off can serve to replenish the groundwater and enrich soil water reserves accessible to the plant. Run-off can also be channeled into ponds for practical (summer irrigation) or ornamental uses.
6. Use marginal water
Wherever technically feasible and safe, plants should be irrigated with marginal water – purified sewage water, grey water (run-off from bathroom showers, sinks and washing machines), and brackish water. But first the long-term effects of irrigating with marginal water on plants, soil and groundwater should be determined and the necessary permits obtained.
7. Reduce lawn area and minimize plants that require abundant water and maintenance
The lawn is the garden’s biggest water guzzler – both because of its high consumption per unit area and because of its size. Seek to confine the lawn to areas where it is essential as a surface for sports, games or relaxation. For the rest of the garden, turn to water-wise solutions such as shaded walkways (paved or strewn with gravel or other material), groves, shrubs, and water-sparing ground-cover plants. Minimize the use of plants with large water and upkeep demands.
8. Choose the right plants
• Choose water-sparing low-maintenance plants suited to the climate and to the soil of the garden. Ill-suited plants will show excessive sensitivity to diseases, pests and stress when exposed to the strains of modern life (air pollution, mechanical damage by individuals and vehicles), an alien climate, or nutrient shortage. A plant that is suffering demands attention and upkeep as well as abundant water and nutrient supplements. Replace species and varieties that are sensitive to disease and pests with hardy species and varieties. This will make it unnecessary to use pesticides. At the same time, to avoid creating conditions that favor proliferation of pests and diseases, be sure to plant a diversity of species and families. Choose species that cover the ground and block weeds and unwanted species from invading the garden.
• Beware of ‘water thieves’ – plants with extensive root systems that enable them to exploit water and nutrients over a large radius at the expense of their neighbors, thereby reducing the availability of water and nutrient to the garden.
• Look for species that provide support and sustenance to creatures such as butterflies, bees and birds – provided of course that they do no damage and are not invasive. These species are important for the food chain and enrich the experience of visitors to the garden.
• Avoid plant species – whether introduced or indigenous – that are likely to prove invasive in the area in question.
9. Mulch the soil
Use an organic mulch. Organic mulching leads to sustained enrichment and amelioration of the soil, and also moderates temperature extremes (hot and cold) at the soil surface. This encourages root development in the topmost layer, which is characterized by better air supply and gas exchange, and promotes absorption of water and minerals and proliferation of microorganisms and other soil organisms. There is less of a tendency for a crust to form at the surface, so water and gases penetrate more readily, reducing run-off and soil erosion. The net result is that more water is available to the plant. In addition, mulching inhibits development of weeds. In this respect, mulch composed of plants containing allelopathic compounds (pine, oak, eucalyptus, casuarina) is preferable.
Organic mulch enriches soils that lack organic matter. Grinding up organic material to prepare mulch or compost obviates the need for disposal by burning, which is detrimental to the environment.
10. Maintain the garden correctly
• Prepare a detailed seasonal maintenance schedule for each type of plant, taking the particular soil and zone into account.
• Weed control: deal with every weed as soon as it appears and eradicate it before seeds are produced (by hand, mechanically, or using a ‘green’ weed killer). This will prevent a major problem from developing and requiring widespread use of herbicides.
• Optimize plant nutrition to prevent excess growth (need for pruning, high sensitivity to pests and disease) and leaching of minerals into groundwater.
• Plant at the correct interval for the particular species: other measures designed to optimize the growth conditions of the plant will improve its appearance without necessitating application of additional water, nutrients or pesticides.
• Check that the irrigation system is in good condition and operating properly.
• Leave the lawn clippings (assuming the grass is mown as appropriate intervals). This will return nutrients to the soil and reduce the need for fertilizers.
A final word
In the course of time, faithful adherence to our Ten Commandments will produce a self-sufficient ecological garden that sustains its plants and whose plants, in turn, sustain those that dwell in the soil and space of the garden in harmony with the environment and with man, for a relatively modest outlay in terms of work days, water and maintenance.