The Bay of Plenty is really two climates wearing one name. Coastal Tauranga and the Mount are mild and largely frost-free through spring, closer to Auckland's timeline than anywhere else in the region. Inland toward Rotorua, the picture changes fast: elevation and still, cold air on clear nights push the average frost season out to ten ground-frost days in July and frost risk lingering into November.
If you're gardening on the coast, tomatoes, capsicums and courgette can usually go in from September alongside the reliable spring list of lettuce, spinach, silverbeet, peas, beetroot and carrots. Inland, hold the tender crops until October or November and treat a coastal neighbour's early-September planting as advice for a different climate rather than your own.
Wind is the other factor coastal Bay of Plenty gardeners plan around more than most. Sea breezes that keep the coast mild also knock over tall, newly staked plants before their root systems have caught up, so a sheltered spot against a fence or hedge matters more here than extra fertiliser or an earlier start. Reliable spring rain across the whole region is a genuine advantage though: new plantings rarely go short of water the way a Hawke's Bay or Marlborough garden can by October.
Wind is the other factor coastal Bay of Plenty gardeners plan around more than most.