Caring for an Olive Tree
I have an olive tree grew well in the last ten years. The last two years there have been no olives and the leaves are all in the top 1/3. Should I prune the bottom leafless twigs?
It is normal for olive trees to lose lower branches and foliage as they age, and they don’t usually crop until they are at least five years old. However in your case the tree is much older than that and you should have seen more regular fruiting in recent years. It usually does not take much to grow an olive tree, apart from choosing the right variety for your region, selecting the right site to grow them, and keeping them pruned to keep fruit low.
Each region has a specific variety that does well in that particular area and it suits the conditions. It would be worthwhile to talk to your local garden centre to find out whether the variety you are growing is actually suited to the region. The site you select to grow them is also important - although olive trees are adaptable plant, they prefer a sunny site with well drained fertile soil, in an open position and plenty of wind to aid pollination.
You could try applying some Daltons Premium Tree & Shrub Fertiliser to give the tree a boost. Just be sure to not over fertilise as you will produce more vegetative growth at the expense of your fruit.