Not sure what would grow in Karori but i do know there used to be a large orchard there many moons ago on Messines road or somewhere near there and the houses around there probably have varieties that they have inherited. always best to have a nosy around our neighboured and ask those that are already growing in your area. your local garden club might know more also. Good luck!
It depends a bit on what your microclimate is, and which of Wellington's winds you are exposed to, and what frosts you do ( or don't) get...... and how much space you have - you can get triple worked apple trees - which have three varieties grafted on to them - I have heard that this is good to do because different weather in different seasons suits different varieties - also if you choose carefully, you can spread your growing season - and I have 3 children - one likes red apples, one likes granny smith, one likes yellow apples!! I have just planted a Billiington plum, but it will take 5 years to fruit apparently - you can also get double-worked plums, but I preferred the fruit of the Billington to the others - some plums need a pollinator, some are self fertile..... Oderlings in Upper Hutt have a really good selection
In the last 12 months I have also planted a grapefruit and 2 feijoas, 5 blueberries, a grape and two berry delights......hoping I will get some fruit before my children actually leave home!! Good luck!
I bought three different varieties....cos I read somewhere that different varieties do better in varying seasons, so it increases the chances that at least some of the bushes will fruit well in a season - can't remember the names off hane, but will check next time I am down there - have kept the labels.....don't know about hedging - probably best to ask a garden centre? Or a grower - there is an organic grower of blueberries in the Akatarawa Valley - they open up to the public for picking, so their number will probably be in the phone book - or you could just drive past and drop in one day?
What are cranberries like to eat fresh? Cos that might be an idea too!!