David Livingston wrote:Difficult with outmore info.
Whats the weather like? particularly frost ? Are all these trees the same type of olive ? Are they self compatable ? How big are the pots ? How old are the plants?
Anne Miller wrote:Maybe the trees are not old enough to produce fruit?
Olive trees do need a certain amount of cold, however. Proper flower development depends on the climate dipping to 45 °F (7 °C) or below, although this number alternates with olive tree varieties. This is why cultivation is extremely difficult in the tropics or very warm areas.
Make sure that bloom season is fairly dry and moderate. Bloom season (April to June) should be fairly dry and not excessively warm. Olives are wind-pollinated, so wet conditions can hamper a tree's fruit set.
Check the pH of your soil and adjust it if necessary. The soil should be moderately acidic or moderately basic, with a pH greater than 5 and less than 8.5. Many farmers believe 6.5 to be ideal. Get your soil tested at the Department of Agriculture or use a home testing kit from a department store. If the pH isn't in the right range, adjust it as necessary
Full sun, without any shade blocking your trees, is ideal. Any area you choose should at least get some direct sunlight for at least six hours a day. Very shady areas are not recommended for growing olives.
Wait several years for your trees to start bearing fruit. Well-watered trees will start bearing fruit two or three times faster than dry-farmed trees. While some cultivars begin bearing fruit as soon as two or three years if properly maintained, many trees won't start bearing until 10 years old. When growing olives, remember this is a long term project. Start watching for fruit after the first two years, but keep in mind it may take much longer for an olive tree to yield fruit.
Steve Farmer wrote:Disclaimer: I'm not massively experienced in growing olives and only have young trees from nursery and planted out fairly recently.
What I have found in my limited experience is that olive trees smaller than those in your photos already have root systems that would be suited to pots bigger than the ones you have. Can you get bigger pots? or maybe trim some of the foliage and buds. It might be a choice between 100 flowers that don't result in olives, or removing 80 of them so that the remaining 20 do.