Hi Jo
Olives (Olea europaea)Olive trees require a well-drained soil and a sunny position. Avoid sites where water stands during rainy periods or where ground water seeps into a hole two feet deep. Do not, however, confuse the olive for a desert plant. It needs regular watering to thrive Insufficient water will cause your tree to suffer, and even die if left too dry for too long.
Water newly planted specimens every third day for the first two weeks. ...
Cut back the watering to once weekly after the first two weeks.
Nitrogen is the one nutrient an olive tree may be deficient in. It is needed for formation of flowers, fruit and leaves. During spring growing season, for mature trees, give each tree 2 pounds of urea or 50 pounds of compost. For young trees, give 1 ounce of urea each month and water it in well.
use a premium slow-release fertilizer with essential minor elements (zinc, boron, calcium, etc.). Use a fertilizer that has a nitrogen analysis of at least ten percent.
[Urea. Urea (also known as carbamide) is a waste product of many living organisms, and is the major organic component of human urine. ... So the liver converts the ammonia to a non-toxic compound, urea, which can then be safely transported in the blood to the kidneys, where it is eliminated in urine.]
Olives are great at "surviving", but if you want them to look good you need to feed regularly, during the growing season, if pot grown. Any balanced liquid feed will be OK, such as 'miracle grow' or similar, but dont feed for a few weeks after repotting, let the roots start to move into the new compost first.
You should be Pruning Olive Trees in late Spring or early Summer when the weather is milder but before flowering. As the olive tree is an evergreen plant, new growth will be produced from most of the pruning cuts. These fresh shoots will be susceptible to damage from cold weather.
To prune an olive tree, choose a time either in late spring or early summer and make sure your tree is at least 3-4 feet tall before pruning. Choose 3-4 strong lateral branches to form your main shape and make slanted cuts to remove branches.
Pruning for shape should not really be done until the tree is at least 2-4 years old as the more leaves a young olive tree has, the more energy it will have to grow into a lovely, healthy specimen.
https://www.wikihow.com/Prune-an-Olive-Treeyou can have any shape
let me know if this helps for more info get back to me
I have grown two olive trees in my old award winning garden [south kensington] both had fruit not to eat
kev