While the type of plant will also need to be taken into account, Autumn in Perth is a great time to plant almost anything – not too hot, not too cold and it gives plants a chance to establish over winter and be stronger with more developed root systems once summer and the heat/drought kicks in. This isn’t always the rule and, thanks to Perth’s Mediterranian climate, if you don’t mind the extra care and fertisling etc. you can plant almost year-ruound without too much trouble. Many flowering plants will depend on when they flower, so it’s always best to check with an experienced horticultralist when you are planting and have a great garden mainteance team to rely on to look after them while they establish.