Water-wise Gardening - Where are we?
As a landscaper, I feel we pay lip-service to water conservation in the landscape industry. Despite the liberal use of the word ‘water-wise’ on plant labels at nurseries, and during design presentations, the fact is that many gardens and landscapes are watered at least twice a week, and often three times.
While some indigenous and water-wise species are indeed adapted to drought, the way that we water (too frequently, not deeply) prevents them from developing strong, deep root systems. Instead of ‘making rain’ with our irrigation systems – giving a long deep watering - we wet the leaves, mist the atmosphere and moisten the top few centimeters of soil – only to have most of it evaporate soon after. Crazy, isn’t it? When one considers that most gardeners are using treated potable water on their gardens, it becomes even more incomprehensible. Imagine emptying 500 bottles of mineral water in one area of your garden – this is the typical water-use of ONE station of shrub sprayers.
Clearly, it is time for a major rethink.
What is a water-wise garden?
Is a water-wise garden one that is watered once a week, or once a month during the dry season? Or not at all? Or since rainfall varies widely across the country, should it be a relative measure?
There is currently no benchmark in the industry for a ‘water-wise garden.' It is a vague relative term that implies ‘less than usual.' Personally, I think this is not good enough! Fourie Petersen suggests water-wise landscaping should be based on a philosophy of sound ‘water management practices’. And ‘management’ requires measurement. Imagine if all landscapers always installed a water meter and rain gauge at each site, and organized weekly data to be collected and submitted to a regional/ national database? If we measure the amount of rain and water applied to landscape, we will have an accurate record and understanding of water-use, and be able to develop a benchmark over time.
Our relationship with water
Is it fair to say that water restrictions help to increase general awareness and appreciation for water? I think so. Switching off automated watering systems has brought us closer to our gardens: we are now tuning into plants and their needs and having to make tough decisions which ones are going to receive the grey water. My pots have never looked better since I’ve put a plastic basin in the kitchen sink for rinse water – it provides a few liters several times a day. In the days when I still had a bath with my young son, and it took me ten full buckets to empty it, I realized that even a shallow bath used a hundred liters. Needless to say, we have been showering since!
Saving and storing water
As landscapers in the Cape, we are often faced with the question of whether to install water storage tanks. This has led to healthy debate when one considers the following: