I don’t know if my neighbours look out their windows late at night. But if they had the other night, they’d have seen me standing in the rain with a garden hose, watering the front garden. They, you and the Water Authority might all wonder why I’m going in the face of standard watering advice, which is to water the plants when they’re dry and turn off sprinklers and auto systems if it rains. But there’s a couple of very good reasons. They are: climate and adaptation.
The front area, my zone 1, is set up with local natives as much as possible, either local to this immediate area or to similar-soiled sandplains a little north of here. Which means all these plants are adapted to long hot dry summers with very little in the way of rainfall. Several of them can actually be killed by summer watering, because the plants start taking down their defences against drought and then, oh oops, it’s still summer. The whole aim of my zone 1 is to have a garden that can be largely ignored across summer and still look vaguely OK. And that means avoiding the need for watering.
The problem is, of course, that a wild ecosystem adapted for these long hot dry summers still takes some losses. Not every plant makes it through the heatwaves. You’re looking at average survival rates, not individual survival rates. But in a home garden I might only have one or two individuals of any given type of plant, and with my mulching to keep down weeds I don’t have ideal regermination conditions for all these low-organic-matter-sandplain-plants yet either. So losing one plant to gain next year’s seedlings is a nice theory but still only a theory. I also have several plants that are still establishing, seeing as the garden is being constructed over a span of a few years, so don’t necessarily have the ability to survive the summer just yet. They will next year, when their root systems have had more than four months to spread, or when the tree next to them has grown enough to shade them at 3 pm in the afternoon, or when they’ve got back to a good flower-leaf balance after being over-fertilised at a nursery to improve their appearance, or whatever it is they need. But they don’t yet. The rule of thumb in a native garden in the city is that you water the plants occasionally if you want it to always look good. I’m willing to accept some losses and imperfections but I do want the garden to establish. So that means occasional watering. By hand, as I’m refusing to install irrigation.
The question is, when. I want the water to have its maximum impact. Which means as much as possible of it has to go into the soil rather than being lost to ambient heat. Which means, watering at the coolest and highest-humidity times and when the plants are anticipating absorbing rainfall. Which means, when it rains.
It’s not as moronic as it sounds. The rain in summer here is usually light, not highly penetrating. It’s enough to cool sand surfaces and collect in tiny depressions and give our natives the relief they need from the heat, but it’s not enough to count as much watering. Especially not with a mulch layer over the soil that prevents the rain from reaching the soil in the first place. If I want the plants to receive rainfall I have to provide extra water. And I know that summer rain doesn’t kill them, only summer watering. So I work to try and give that balance, and make my watering as if it were just that little bit of summer rain. If that means I only water four times in four months, that’s perfect.