Generously, olives will grow and fruit on poorer, shallower or more gravelly soils than most orchard trees. Very fertile soils tend to encourage excessive vegetative growth at the expense of fruiting. I'm feeding ours like mad because I want lush, thick, beautiful trees, not olives.
Olive trees and bushes are generally container-grown, so you can plant them at any time of the year. Now's good, though, because it allows the tree to become established before it gets cold again. A semi-mature tree will have quite a large spread. If you have only a terrace or a courtyard, you can plant olives in big tubs or containers. They don't seem to mind, and of course it's very trendy. Irrigate them carefully - overdoing it will kill them. And mulch in early summer to retain soil moisture and control weeds.
The trees don't begin fruiting until they are about 5 years old (ours were precocious and started sooner than that but we just ignored them) so the larger the specimen the sooner it will produce fruit.
Cool winters, hot summers, not too much humidity and good air movement - they are mainly wind-pollinated - are important.
We've pruned our trees for shape - and because The Landscaper can't seem to stop himself lopping the tops off things. But if you're going for fruit the idea is to keep the trees low and broad for stability and ease of picking. Usually a broad vase shape with three or four main leaders is favoured.
Interestingly, olives tend to bear heavy and light crops in alternate years. Clever of them, I think, to have a gap year, so to speak.
However, if you want to lessen this tendency you can prune off a proportion of the fruiting wood after a light crop or soon after fruit-set of a heavy crop.
It's hard to imagine why they'd want to, but birds eat olives when they're ripening and rabbits may damage the bark. Other pests and diseases you may have to combat are fungal diseases, a native weevil that causes distortion and death of young shoots, and damage by leaf-rollers and cicadas, particularly in the first year or two.
Possums, sensibly, are not remotely interested in any part of the olive tree. Like me, they can't see the point in gathering fruit unless you can eat it straight away.
DIY olives will keep you busy for days
Should your olive trees turn out to be heavy fruiters, you may feel a moral and environmental obligation to pick, process and eat them. But be warned - it's not like bottling plums.
Picking them is the easy part. Spread out a tarpaulin and rake of the fruit with a wide-toothed rake. Then there's the not-so-easy part. Put them on a clean, hard surface and either bruise with a rolling pin or prick with a fork. This helps the salt and water to which you are about to introduce them to penetrate the fruit.
Put them in a bucket of water with half a cup of coarse salt per 10 cups of water. Put a breadboard on top to help keep them submerged. Replace with fresh salted water daily for 10 to 12 days and then test by biting. When the bitterness has nearly gone they need one more salting.
And no, it's not over yet. Pour off the last of the salted water and measure it. Then measure an equal quantity of warm water into a pot and dissolve the salt at the ratio of 1 cup salt to 10 cups water. Boil and then cool. Put the olives into jars and cover with the brine.Top up the jars with a centimetre of olive oil to stop air getting in. Seal.
But wait - there's more. Before eating, drain off the salty brine and fill the bottles with cool water. Refrigerate for 24 hours. If they're still too salty to eat, fill the bottles with hot water and refrigerate again for 24 hours.
Once the correct salt level is reached you can add extra flavours such as basil, capsicum, garlic and lemon juice - if you have any energy left.
