I just moved in to a new house where there is an olive tree planted in a clearing of about half a sidewalk square. The tree is about 25 feet tall, has many shoots coming out of the bottom, and currently looks like the attached photo. It also has (though it has dropped most of them now) dry, shriveled black olives.

I have several questions--and if there is a more appropriate board, please point me there.

1. How should I care for this tree--watering, fertilizing, pruning if I want to harvest olives. I believe it has been surviving without much/any input.

2. Is there any way to tell what type of olive tree this is--is it even good for eating or should I just let it survive without much water and not bother curing the olives (of course, I'll try a few batches to see what I think)

3. When should I harvest these olives? I guess October is the commercial oil harvest around here--is it earlier for curing?

4. Any hints on how to harvest. Most are too tall to hand pick--I've seen shaking is a common method, but I'm on a hill and on the street, so any shaking will send most of the olives down the storm sewers, unless there is some sort of net made for this purpose that hooks on to the tree bottom.