Correction: This story originally named the incorrect person interviewed. Hannah Zwartz spoke to Saturday Morning, not Kath Irvine.
A sprinkle of water every other day may not be the ideal way to keep your garden watered during summer. Photo: 123rf
While gardener Hannah Zwartz loves wandering around with a hose in the morning, she says frequent light watering of a garden is not the most effective.
Although vegetables need water more frequently, the rest of your plants will be happy for their soil to get a really deep soaking once a week, she tells RNZ's Saturday Morning.
When plants regularly receive water right down at their roots they become stronger, Zwartz says.
"If you're just sprinkling the top layer [with water] it will dry out more quickly, whereas if you get the water right down into the soil you're encouraging deep-rooted plants, which are more resilient.
"If the top layer dries out the plants have still got their roots down deep in the soil and they're not so needy. They won't wilt so quickly."
As well as adding water to your soil, you want to slow down its departure, Zwartz says.
Bare, wind-exposed soil dries out quickly, and the best "sun hat" for it is a layer of mulch. This can be any plant material off the ground such as bark chip, straw or leaves.
Trapping water in the soil before it evaporates is just one of the many benefits mulch delivers to a garden, she says.
"As well as holding the moisture, it also keeps the weeds away so it can save you a lot of work in that way. Also, it's really good for the soil texture as it breaks down. The organic matter will help your soil, in the long run, to hold more moisture and stop it from running away. It feeds the worms. So there's a whole lot of reasons to mulch your garden."
The best time to layer mulch on your garden is straight after a big rain when the soil is wet, Irvine says. The next time her garden gets a downpour she'll pack down a mulch made from overrun parsley and silverbeet.
"I just chop them up into sort of 10-centimetre bits and put them on the ground. it's kind of like using what you've got as much as going out and having to buy something."
Mulch, such as fallen leaves, is a "sunhat for the soil". Photo: Annie Spratt
For tomato beds, Zwartz's "favourite long-term watering system" involves a terracotta garden pot plugged up with a cork and buried up to its neck nearby.
We see all these fancy irrigation systems, she says, but 'slow watering' vegetables by regularly filling this terracotta pot is effective and easy.
"You fill that pot with water and because it's terracotta it is porous and it gently soaks [water] into the ground.
"If you have a terracotta pot sunk into the ground and fill that with water, it will slowly seep out over a matter of hours, and that will benefit your plants.
"It means you can go around with your hose and just fill up the pots. Or if someone else is watering your garden it's really easy for them to see what to do."
