Basically from the start of October to early November is considered tomato planting time in Melbourne but exactly when to plant out your seedlings depends on the microclimate of your garden. If your veg plot is sheltered from cold wind and gets lots of sun, or you have raised beds (which warm up quicker than an in-ground garden), or you are growing your toms in large pots (again, warmer than in-ground beds), then you can get away with planting them now. I have a heavyish clay-based soil which tends to take a little longer to warm up, so will not be planting mine out until around the end of this month. As far as planting in less than full sun, the minimum recommendation for plants like tomatoes is usually given as 6 hours of sun a day, so your patch doesn't necessarily need to get sun from dawn to dusk. If it's currently getting 6 hours you can proceed as per usual. I have a spot in my garden that is shaded by a shed in winter/early spring, which I'll be using for a tomato plant this year. I'll pot up the tomato seedling destined for that spot (an early fruiting variety) into a bigger pot as necessary, and plant it out mid-November, by which time the space gets about 6 hours and the seedling will be a good size.

- Tracey in Melbourne