37.7°C average max, 22.2°C average min, 16% rain chance, 0.0 mm total. That’s the Red Centre forecast I’m looking at for Alice Springs and Tennant Creek this week, and it’s the number that’s making me rethink what’s still in the ground.
Arid zones: I’m mulching now, not when it wilts
Red Centre and Western NSW (Broken Hill, Dubbo, Bourke) are both sitting on zero rain and heat in the mid to high 30s. Western NSW’s at 34.8°C max, 19.6°C min, 12% rain chance. No relief coming from the sky in either patch.
If I’ve got anything leafy still in, I’m pulling it now rather than watching it bolt. Lettuce, rocket, coriander all throw up a flower spike and turn bitter once the soil’s been baking at these temperatures for a few days straight. My rule for this kind of week is a deep soak every three days rather than a shallow sprinkle daily. A quick surface wet just evaporates by 10am and trains roots to stay shallow, which is the opposite of what I want when there’s no rain in the forecast at all. Mulch goes on thick, at least 7 to 10 cm, over anything I’m keeping. Bare dirt at 37°C loses moisture I can’t replace with a hose fast enough.
Southwest WA: dry heat, different problem
Perth, Fremantle and Mandurah are cooler on paper (32.9°C max, 18.7°C min) but the rain chance is even lower at 6%, with 0.0 mm total. I treat this one as a shade problem more than a water problem. My tomatoes and capsicums are the ones I watch here. Blossom drop kicks in once daytime heat sits above 32°C for several days running, and this week qualifies. I’ve had good luck with 30% shade cloth over the flowering trusses from midday to about 4pm. It doesn’t stop the heat, but it buys the flowers enough relief that they don’t abort.
Tropical zones: heat plus humidity, not heat plus dry
Top End (33.1°C, 63% rain chance, 139.7 mm), Wet Tropics (32.8°C, 55%, 136.8 mm) and Dry Tropics (32.7°C, 43%, 120.7 mm) are all running hot too, but with real rain behind the numbers. That combination, heat in the low 30s stacked with high humidity, is where I see fungal issues before I see wilting. If I’m growing anything in the brassica family up there this week, I’m checking undersides of leaves for the first sign of mildew rather than worrying about drought stress. The soil’s not going to dry out. My concern is airflow around the base of the plant so that 130-odd millimetres of rain doesn’t just sit there.
Three zones, three different heat problems this week, and none of them fixed by watering at a particular time of day. The only genuinely hard part is remembering to check the shade cloth before I leave for work, not after.
