[WG.]

frosts can be anywhere from june to august but usually only about 6 weeks worth if that

I see from your blog that you utilise a few Australian forums too so their advice will doubtless be more relevant / practical than mine.  But here is my 'take' on it - PROVIDED you can get seed potatoes all year round.  (If not, keep them in the fridge).   Newly harvested tubers are not ready to spring back into life for the next crop.

This is an intensive plan for 4 harvests of first early potatoes from one area of ground - goes against organic principles somewhat but a useful academic exercise.  You'll need to add large amounts of rotted manure and water.  

First sowing : Plant 3rd week of July.  Be ready to mound up any which surface before mid August.  After that, danger of frost should be past. Expect to harvest around end September

Second sowing : First week of October.  Expect to harvest late December.

Third sowing : First week of January.  Expect to harvest late March.

Fourth sowing : First week of April.  Expect to harvest after first frosts.

Is Potato Blight a problem locally or is your humidity sufficiently low to thwart it?

[DellDGM]

this is great info wg - we don't get much hummidity here just dry and hot hot hot - although every year it gets a little bit more humid. - I will try this planting plan and see how I go. Ta

[WG.]

Do please post again with some feedback for us.  It must be said that tatties are not really a hot-weather crop - you may find you have to cover them with fleece to prevent leaves getting scorched and reduce transpiration.  Again your other forums should contain much more localised hints and tips - I can assure you that my talking of leaf-scorch in the middle of winter in the Scottish Highlands is 100% theory!