Gardening – Preparing for the big dry

The pundits are predicting that we will be in for a drier and windier summer than normal due to the strong El Niño weather pattern this season. During an El Niño, water for gardening can be a valuable resource, particularly for rural properties on tank water, but also for suburban properties when the council brings in water restrictions. With so much advance warning, there is plenty of time to prepare your garden to keep it green and lush.

A good water conservation method is to spread a thick layer of mulch at the end of spring while the soil is still damp. Effective mulches include sea grass, grass clippings, sawdust, straw, leaf litter, woodchips, old woollen carpet and even gravel. Woodchips can be layered up to 5cm deep – less for some of the softer mulches and avoid placing the soft mulches against the stems, as rotting mulch can cause collar rot on some plants.

Mulching helps keep moisture in, protects roots from drying out, keeps the roots cooler, encourages worms and other beneficial soil micro-organisms and reduces the chances of soil becoming hydrophobic, which is where water just runs off. It’s best to water thoroughly before mulching or wait until just after heavy rain, as once mulched, more water is needed to penetrate to the soil.

Choosing the right irrigation method is important. For the greenhouse and veggie gardens, “leaky” hoses, soaker hoses and drippers are the most efficient and keep water off the foliage, which reduces evaporation and reduces the potential for disease. In ornamental gardens, permanently installed mini-sprinklers or driplines save both water and time and can be set up so water isn’t wasted on paths. Rotary sprinklers are best for covering large areas such as lawns and fruit trees. These deliver water per square metre more slowly than the other systems, allowing more time for the water to soak in, but they are the most wasteful method.

During watering, make sure you are putting enough on to soak the dry layer and into the moister soil below, to supply sufficient reserve till the next rain or irrigation. Light watering encourages shallow roots, making the plants more prone to drought. Deep watering encourages roots to grow deeper, helping them access more water and nutrients. This is particularly the case for most shrubs, perennials and long-lived veggie crops such as tomatoes and capsicum, less so for short lived crops such as flowering annuals, cucurbits and quick growing veggies such as lettuce and rocket.

Always try to water in the early morning to avoid sun burnt leaves, reduce evaporation losses and reduce the risk of disease. If your crop is wilting though, water at any time, as a lack of water is far more serious than any of these other risks. Don’t apply water from hoses that have been lying in the sun, this can be very hot and burn leaves and surface roots. Let this run into a bucket for use later.

Try to capture as much rainwater as possible – every roof surface, no matter how small, can be a potential water source with a drum or bucket placed under the drip line or downpipe. The more of these dotted around the property the better, as they are handy to grab when you see a plant suffering from drought.