Olive Tree Pollination
Many varieties of olive trees require cross-pollination but most the varieties that we sell do not because they are self pollinating or self-fruitful. This means that bees or wind can pollinate a single tree and it will bear fruit all by itself. Pollination occurs when the trees blossom. Pollen from the anthers (the male part of the plant) has to be transferred to the stigma (the female part of the plant). Completed pollination fertilizes the tree and fruit grows. Otherwise, flowers grow, but not fruit.
These varieties of olive trees are wind pollinated, the Arbequina, Arbosana and Koroneiki, Fantoio and Coratina can also be used as pollinators.
Other olive trees, like Ascolano or Mission are cross-pollinating or self-unfruitful. They need another tree or sometimes two other trees for pollination, not of the same variety, but a different variety of the same fruit. In other words, the Ascolano tree needs a Manzillo and a Mission and they all have to blossom at about the same time.
However, even if the trees are considered compatible, other factors can interfere with pollination. Lack of rain, high winds or frost can damage buds before they blossom. Olive trees in Florida form their flower buds in February and March. Excessive winter cold or even a late-spring frost can kill buds and blossoms. That's why it’s important to choose the right olive tree for your hardiness zone.
When these varieties of olive trees do cross-pollinate you benefit with a higher yield of 10% or more. When olive trees cross-pollinate it does not change the fruit of the tree but it changes the seeds in the fruit of the tree which then grows to be a hybrid tree. Cuttings of your tree will be clones, seeds germinated from the fruit of the tree will then be hybrids but the hybrid tree may take 10- 15 years to fruit, if the seed is not sterile.
These olive tree varieties should be spaced between 6 feet for a high density grove or 18 feet for a traditional grove . Place the tree where fallen fruit won't cause a problem — away from decks, driveways and walkways.
Try to use only organic fertilizers for nitrogen and potassium feeding or natural pesticides if needed.