Your olive tree pollination requirements depend on the type you grow. Most olives need pollen from a different cultivar to set fruit well. A single tree of most types will produce few olives or none at all. You need a partner tree nearby to get good crops.
I learned this the hard way with my first olive tree. It flowered for three years straight without making a single fruit. Then I added a second variety about 30 feet away. The original tree loaded up with olives the next spring. The difference was night and day.
Olive cross pollination works through wind. The breeze carries pollen between different cultivars during bloom time. Research from UF/IFAS confirms that most olive varieties are self-sterile. Their own pollen won't work on their own flowers. You need pollen from a tree with different genes to get fruit.
Some self-pollinating olive trees exist and these make your life easier. Arbequina and Mission can set fruit on their own without a partner. Even these self-fruitful types produce bigger crops when another variety grows nearby. They work alone but perform better with friends around. Pick one of these if you only have room for a single tree.
Other popular varieties need partners to produce fruit for you. Manzanilla needs another type to make olives. Frantoio and Sevillano face the same challenge. If you plant one of these you must add a different variety within range. Otherwise you'll see empty branches at harvest time and wasted years of growth.
Spacing matters a lot for good pollination results. Plant your second variety within 50 feet (15 meters) of the first tree. Closer is better since wind drops pollen before it travels far. I keep my trees about 20 feet apart and they work great together. Your whole yard can fit both trees if you plan the layout well.
Bloom timing affects your pollination success. Both trees need to flower at the same time for this to work. Early bloomers won't help late bloomers if their flowers don't overlap. Check bloom times before you buy a second variety. Your nursery can tell you which pairs flower together.
For the best fruit production plant at least two different olive varieties in your yard. Pick one self-fruitful type and one that needs a partner. This strategy gives you backup if one tree blooms early or late. Your harvest will be bigger and more reliable with mixed varieties. The extra tree pays for itself in just a few good harvest seasons.
Read the full article: Growing Olives: Step-by-Step Plan for Home Gardeners
