Olive our Knowledge – Olive Tree Grow Guide
Growing your own olives in the backyard orchard or in a container is not only possible, but easy and very rewarding.
Olive trees do best where the summers are long, hot and dry, and the winters are cool and not so dry. They like a sharply drained calcareous or limey soil, and can tolerate salty, coastal locations. Many olive varieties require cross-pollination; that is, you need at least two different varieties to reliably get fruit. Perfect Plants offers the Arbequina olive variety which is self-fertile. To produce olives, the Arbequina olive tree requires at least 300 chill hours; that is, 300 hours below about 45°F in the wintertime, making it well adapted for in-ground cultivation in USDA Zones 7B-9 (find your zone). Where not hardy, you can grow Arbequina olives in a container to be brought indoors in the winter. The Arbequina olive is semi-deciduous, usually dropping some of its attractive gray-green leaves in the winter. Arbequina tends to bear heaviest in alternate years, and fruiting may be increased when another variety is nearby for cross pollination.
Once established, olive trees need little care or maintenance. Under good growing conditions, you should expect to harvest some olives by the time the trees are 3-6 years old.
For outdoor cultivation, situate your olive tree where it will get a minimum 6-8 hours of sun per day, and preferably full sun all day. The soil must be very well drained; olive trees don’t tolerate heavy, clayey soils. Arbequinas can get up to 20 feet tall and 15 feet wide, so plan ahead. Multiple trees should be spaced about 10-20 feet apart.
Dig the planting hole about twice as wide as the pot and at about the same depth. Straighten out and/or trim any coiled roots before placing the root ball in the hole. Do not bury the plant deeper than it was in the pot. Do not add fertilizer at this time. Fill the hole in with the original soil and water deeply. Spread a layer of organic mulch about 4-6 inches deep over the root zone and a little beyond, but avoid piling it against the trunk.
For the first six months, while the new tree is getting established, it should be watered deeply two or three times a week.
Pruning olives is tricky so take your time! Do not prune in the first year. In the second year you should begin training the tree for its mature shape. Allow for a central leader with three “scaffold” side branches. After a few years, you can prune for a secondary scaffold system on the first three side branches.
Olive trees bear fruit on the previous year’s growth, and they never bear on the same wood twice. They should be pruned in spring, removing shoots that bore fruit the previous year, but leaving new shoots that just developed the previous year. Remove suckers and water sprouts whenever you see them.
Olives, generally speaking, alternate years for bearing fruit. Meaning, every other year you will have heavier fruiting than the year before. On off years, pruning non-flowering branches during the flowering period can help home gardeners tremendously for fruit production.
Mature olive trees are very drought tolerant, but if they get about an inch of water every week or ten days during the spring and summer, they will produce more and larger olives.
Don’t lose hope if you don’t live in the correct zone for growing Arbequinas. Recent studies have shown that it is still possible for fruit production in areas with warmer climates like Southern Texas or Southern Florida. The solution would be to plant the tree where it will receive a decent amount of shade during a warm winter.
For container cultivation, select a pot that is larger than the nursery pot it came in and has big drain holes. Use a free draining potting mix with some gravel or sharp sand mixed it to make the drainage even better. Position the container in full to mostly full sun during the summer and water when the potting medium is dry to the touch. You may have to water daily, but be careful not to overwater. The soil should dry out between waterings. Bring the container inside to the sunniest spot available when temperatures get below 25°F. An eastern or western facing window would work best for full sunlight. After a couple years you will want to re-pot up to a larger container, replacing as much of the potting medium as practical.
Fertilizing your Olive Tree
Olive trees, in the ground on in a container, should be fertilized with a balanced fertilizer (for example: 10-10-10 with micronutrients included) every 2-4 weeks starting in its second spring. For a 10-10-10 formulation, apply about one cup for each year of age. Always follow label directions and do not let the fertilizer touch the trunk. Stop fertilizing in late summer so you don’t encourage new growth that could be damaged by frost.
Your olive tree should start producing fruit after 3 years. Olives are generally green at first but then turn a blackish purple when fully ripe. Arbequina’s can be made into a table olives for eating, but more commonly are used in making olive oil due to their buttery and fruity flavor.