The West Coast gets more rain than almost anywhere else in the country, and for a spring garden that cuts both ways. Soil here stays consistently moist without the watering effort a drier region demands, which suits leafy greens and brassicas particularly well: lettuce, spinach, silverbeet and the rest of the cool-season crops rarely dry out or bolt from stress the way they can further north or east. Frost risk clears by October most years and doesn't return until April.
Peas, beetroot, carrots and dwarf beans round out the safe September planting list. Tomatoes, capsicums and courgette are worth waiting on until October, once the last of the cooler nights have passed, and they'll generally need more attention to airflow and spacing than a drier region's plants do, given how much longer foliage stays damp after rain here.
The same rain that keeps soil moist also keeps slugs and snails active almost year-round, and West Coast gardens see heavier pressure from both than most of the rest of the country. Raised beds help on two fronts at once: better drainage in the heaviest, wettest ground, and a small but real physical barrier that ground-level slugs have to work harder to cross. Seedlings are the most exposed stage, so protect trays and young transplants until they've got a few true leaves rather than waiting for visible damage.
The same rain that keeps soil moist also keeps slugs and snails active almost year-round, and West Coast gardens see heavier pressure from both than most of the rest of the country.