By accident, we chose a very popular Spanish olive for our first batch of 100 trees - Manzanilla (or Manzanillo or Manz). It makes up 60% of all table olives worldwide.
We have room for about 200 more trees and now the question beckons: what next? I was thinking of planting 3 lots of a hundred trees each of 3 different types. Manzanilla = done. Being the worlds greatest fan of Kalamata olives, that's a no-brainer and nothing is going to stop me from planting at least 100 Kalamata trees.
Which brings me to the last batch of 100 trees. After some careful consideration, we came up with a short (?!) list consisting of: Verdale, Sevillano, UC13A6, J5, Borouni, Ascolano, Azapa, Hardy's Mammoth and Gordal.
J2 made the list very briefly, but since the fruit (and trees) are fairly small, we decided against it.
Verdale is currently also busy sliding off the list, mainly because I cannot find any conclusive evidence that it is better for pickling than oil. There are three different varieties: standard Verdale, South Australian Verdale and Wagga Verdale. The South Australia Verdale produces the largest fruit of the three, and might still be an option if we can get out hands on the trees.
Sevillano, also knows as queen olives (from what I could find out so far) is currently highest on the list. Not sure if we would be able to buy the trees in NZ. Need to explore further.
UC13A6 is an American olive. Specially grown for pickling, but again - not sure if we could buy them in NZ.
J5 - need to do more research.
Borouni comes from Tunisia. Large table olive. Not sure if it's commercially available in NZ.
Ascolano - need to do more research.
Gordal - need to do more research.
Azapa - need to do more research.
Hardy's Mammoth - need to do more research.
Other well known varieties like Frontoio, Leccino, Koroniki, Picholene, Arbequina etc, are mainly used for olive oil production, due to their small fruit, texture, size of pip and flavour.
Dual purpose olives (for oil and pickling) include Barnea, Hojiblanca and Manzanilla(!).
I'm not any closer to a final decision. It will also be dependent on availability in NZ.