Gardening with less water

Sunday, 02 June 2019

Succulent plants cope with limited watering; in the garden of Jill Budden in Springwood NSW

As of 1 June, Sydneysiders must observe 'level 1' watering restrictions. It's hard to believe that it is 10 years since we last had these, and I think many of us gardeners, myself included, had more or less forgotten all about those days. However, at one stage, we were at 'level 3' restrictions, being able to water with a hand-held hose or with a drip irrigation system only on Wednesdays and Sundays before 10 am and after 4 pm. At that time, some country towns such as Goulburn, were on 'level 5' restrictions, meaning that no outside water use was allowed at all, and many inland areas are currently implementing similarly severe limits due to the ongoing drought.

I seem to recall that when the measures were first introduced in Sydney, we met them with a mixture of disbelief and outrage. For those who had installed expensive spray watering systems to irrigate their gardens, it was a great shock, and this is going to be confronting again now, as these had made a comeback in recent times as memories of water restrictions had faded. We all thought the restrictions back then would be temporary, but with continued lack of rain in our region, they became part of our lives for a long time. This may be the case again this time, perhaps even permanently, as we face changes to our seasonal weather patterns that we possibly didn't imagine 10 years ago.

Many salvias need little water once established: Salvia leucantha in the erstwhile Sydney garden of Alida Gray

Yet we did manage to adapt to those restrictions, even though they seemed impossible when we first heard about them, and we can do so again. The current rules that relate to gardens are that all hoses to have a nozzle or attachment for instant on-off use. Lawns and gardens are not be watered between 10 am and 4 pm. Sprinklers and watering systems are not permitted, except for drip-irrigation or automated systems with controllers that limit usage based on soil moisture and weather. See here for further information on the rules.

A compost heap can provide valuable organic matter

We really do need to re-evaluate our gardening practices and start again to do all those water-saving things that we were doing 10 years ago. We discovered then that lawns don't actually need to be watered: they do brown off in long periods of dry weather, but they recover once a shower of rain occurs. Mulching garden beds to reduce surface evaporation and reduce weeds that compete with plants for moisture, and increasing the organic matter (compost, for example) in soil to improve its water-holding capacity will really help, as will adding a soil-wetting agent to soils where water runs off the surface instead of soaking in. I am not a fan, however, of hydrogels or water crystals being added to the soil, as the longevity and safety to human health of these products are in question.

Drip irrigation line

To irrigate our plants, conscientious hand-watering (using a trigger-nozzle, of course!) can be effective if you have the time. Spray watering systems can be changed into drip-systems: there are a variety of drip system materials available, including rolls of tubing with in-built drippers, which are fairly inexpensive and easy to install. I have been using such a drip system for 15 years now, since we removed our sprinkler system in 2003. Drip systems should ideally be run in the early morning, to avoid encouraging fungal pathogens that may proliferate if they are run in the evenings, and to minimise evaporation.

Water tank in the garden of Anne Prescott in Sydney

Installing a rainwater tank is another option; in some areas these are mandatory for new houses. There is a joy in being able to use rainwater you have collected yourself (provided we do ever get any rain again!), however and whenever you like, and surely it is better for our plants than treated water from the tap! Grey-water recycling systems are another option, and some of this water can be used for gardens, as long as various precautions are followed.

Plectranthus species and Liriopes such as the cultivar Samantha grow well with little water

We do need to think about the sorts of plants we are growing. The resilience of many plants in coping with less water when put to the test is truly amazing. Local native plants are an obvious choice; and I have previously mentioned some of my favourite garden survivors in blogs, such as here, here and here. I continue to advocate that we do our main planting in autumn or early winter (right now!), as this will give our plants more of a chance to settle in with what water we can provide to them in the cooler months, rather than trying to establish them in spring, which in recent years has brought very warm, dry weather at times.

Luxuriant growth in a wicking bed in the garden of Maree Ross in Sydney

The use of wicking beds to grow water-loving plants such as vegetables is an idea to contemplate, as these use a reservoir of water for plants that seems to be very efficient. There are lots of instructions online as to how to construct such a bed. Another concept is the rain garden, a designed depression in the ground planted with tough species that can tolerate both moisture and drought, that captures rainwater runoff from driveways and compacted lawns, filters it through various layers and allows it to be absorbed into the ground rather than going off down the stormwater drains, providing a variety of benefits to the environment.

I was probably not the only Sydney gardener to give my trusty old sprinkler one last workout on Friday before consigning it to the garden shed. But I believe we can face the challenges of the watering restrictions without giving up on gardening. And please remember to support our nurseries in the tough times ahead! In a changing world, we need gardens and plants more than ever before.