Tree · Oleaceae
Olive
Olea europaea
Give it full sun, lean soil, and a dry root run, and the olive thrives for generations.
Full sun
Every 14–30 days
USDA 8–11
20–49 ft · 6–15 m
Overview
The olive is a slow-growing Mediterranean evergreen that thrives in hot, dry country where few other trees bother to fruit. Growers have raised it for oil and fruit across thousands of years, and a single tree can power on for centuries. Plant one and you are kicking off a project that outlasts you, which is exactly what makes it such a thrill to grow.
The best part is how little an olive demands. Hand it full sun, sharp drainage, and lean soil, and it charges ahead on poor, rocky, and chalky ground that would flatten a fussier tree. Drown it in water or plant it in rich, soggy soil and it stalls, but ease off and it rewards you handsomely.
One quirk fires up the fun. The fruit you pluck off the branch is way too bitter to eat raw and has to be cured first, which turns a backyard harvest into a genuine project. The tree also wants a touch of winter chill to flower well, so it rewards warm-temperate gardens rather than the tropics.
Care
The short version: give it full sun, sharp drainage, and lean soil, then water deeply but rarely once the tree is established. Ease off the feeding, skip the standing water, and prune in late winter to keep the canopy wide open.
Light
Olives chase the sun and demand full sun all day to fruit at their best. They will scrape by on a bit of partial sun, but a shaded tree shoots up lanky and sets a thin crop, so hand it the brightest spot in the garden.
Water
Once established, the olive turns genuinely drought tolerant and would far rather take a deep soak every 14 to 30 days than a string of little sips. Let the soil dry right out between waterings. Soggy, waterlogged roots are the fastest way to fell a tree that could otherwise power on for centuries.
Soil
Drainage beats richness hands down here. Olives romp away in well-drained sandy loam and shrug off poor, rocky, and chalky ground across a wide pH of 6.0 to 8.5. The one thing they refuse is heavy soil that traps water around the roots.
Temperature
The olive laughs off real heat, up to about 100°F (38°C), and sails through a dry Mediterranean summer. Cold is its soft spot, since it takes only brief dips to around 19°F (-7°C) before the wood suffers, so keep it in a warm-temperate garden.
Humidity
Dry air is exactly the olive's element, and it thrives in low humidity around 20% to 50%. Damp, still conditions unleash the fungal leaf spots that plague it, so cranking up the airflow beats any moisture in the air.
Feeding
Olives are light feeders that thrive lean, so hold back. One balanced, nitrogen-rich feed in spring fuels the whole season. Pour on more and you just pump out soft, leafy growth at the cost of fruit.
Pruning
Prune in late winter to early spring, throwing the canopy open into a loose vase shape so light and air blast right to the center. Rip out suckers, dead wood, and crossing branches. An open tree fruits harder and fends off the fungal spots that fester in dense, shaded growth.
Repotting
Container olives crave a repot every 2 to 3 years to keep charging along. Watch for roots circling the pot or bursting from the drainage holes, water rushing straight through, and growth that stalls, all flags the tree has outgrown its home.
Size & spacing
Turned loose, an olive rockets to 20 to 50 feet (6 to 15 m) tall with a broad, spreading crown. Hand it room to match, around 15 to 30 feet (4.5 to 9 m) of clearance, since this tree digs in for the long haul.
When to plant
The olive runs on a slow Mediterranean clock, and following it is half the fun. Get young trees out in spring once frost clears and the soil warms, watch for bloom in late spring, and reap the fruit through fall, from September into November.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: spring after the last frost once soil has warmed
- Harvest: blooms late spring; fruit harvested fall (September to November)
Hardiness
USDA hardiness zones: 8–11
Temperature: down to -12°C
Troubleshooting
Nearly every olive hiccup traces back to wet conditions and wounds, whether it flares up as a bacterial gall or a fungal leaf spot. Spot the early signs and a dry-season prune usually turns it around fast. Match what you see below, then jump on it before it races through the canopy.
Branches suddenly wilting and dying back on one side
A limb that droops out of nowhere, usually on one side, spells verticillium wilt, a soilborne fungus that jams the tree's plumbing and kills off whole branches. Slice into a wilting stem and the stained wood gives it away. Nothing cures it, so act decisively: strip out the dead wood, dial back the water, and steer clear of replanting olives anywhere the disease has struck before.
Fix:
- Remove and destroy dead wood
- Avoid overwatering
- Do not replant olives where the disease is known
Rough woody galls popping up on twigs and branches
Those knotty swellings are olive knot, a bacterial disease that muscles in through pruning cuts, frost cracks, and leaf scars and really runs after wet weather. Tackle it head on: pick a dry day, slice the infected wood out well below the galls, and wipe your tools between cuts so it hitches no rides. Follow up with a copper spray after pruning or a frost to shut the door on it.
Fix:
- Prune out infected wood in dry weather well below the galls
- Disinfect tools between cuts
- Apply a copper bactericide after pruning or frost injury
Punctured fruit with grubs tunneling the flesh
Tiny stings and pale grubs boring through the flesh mark the olive fruit fly, whose larvae feast inside the ripening fruit. Crack a suspect olive open to nail the diagnosis, then hang baited traps as harvest closes in. Stay on top of it by picking promptly and clearing every dropped fruit, and bring in approved bait sprays or kaolin clay when the flies swarm thick.
Fix:
- Harvest promptly
- Sanitize fallen fruit
- Use approved bait sprays or kaolin clay where infestation is heavy
Peacock-eye rings on leaves that yellow and drop
Sooty circles ringed with a yellow halo are olive peacock spot, a fungus that moves into the shady lower canopy through cool, wet spells and sends leaves tumbling. Open the tree up with a good prune so air rushes through, and rake out the fallen leaves where the spores hunker down for winter. Hit it with a copper fungicide in fall, ahead of the rains, to keep it firmly in check.
Fix:
- Improve air circulation through pruning
- Apply a copper fungicide in fall before rains
- Rake and remove fallen infected leaves
Toxicity
Here is a win for homes with animals: the olive tree is non-toxic and safe to grow around pets, livestock, and people, and the fruit even turns edible once cured. The one real hazard is that hard pit, which can choke a pet or block the gut if swallowed whole, so keep fallen fruit picked up.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Great news for cat owners: the olive tree is safe and packs no toxicity at all. The one thing to track is a swallowed pit, which can lodge in the gut, so sweep up fallen fruit and you are set.
Dogs None
Dogs can share the yard with an olive and face zero poisoning risk. Keep tabs on the firm pits, though, since a gulped stone can choke or block the gut, and leave the salty cured olives off the menu.
Horses Safe
Horses grazing nearby run no toxic risk, since the foliage carries nothing harmful. Just stay ahead of windfall fruit so it never piles up, because a swallowed pit is a choking hazard.
Rabbits Safe
Rabbits are in the clear around this plant, which is non-toxic to them. A whole pit is far too big and hard for them to handle anyway, so clear dropped fruit from the hutch and run.
Livestock Safe
Goats, sheep, and cattle can browse around olives with no poisoning risk whatsoever. The hard stones are the one thing to mind, since a swallowed pit can lodge or choke.
Birds Safe
Olives carry nothing toxic to birds, and wild ones go straight for the fruit. The catch is that dense pit, which can choke a smaller bird trying to gulp it down whole.
People Safe
Cured olives are a kitchen staple and totally safe to eat, though raw fruit off the tree is far too bitter to enjoy. Steer clear of biting the hard pit, and watch that small children do not swallow one.
The hard fruit pit is a choking and gastrointestinal obstruction hazard if swallowed, and cured table olives are very high in salt, so neither should be offered to pets.
Varieties
Olive cultivars split mainly into oil growers and table growers, plus a handful bred to drop little or no fruit. Here are the standout names you will bump into most.
Arbequina
A small, self-fertile Spanish cultivar that beats the cold better than most and dives happily into oil pressing or a patio container.
Mission
A cold-hardy California cultivar that pulls double duty, delivering great table olives and pressing oil alike.
Manzanillo
A rounded, widely grown table olive that shines above all for canning.
Frantoio
The classic Italian oil cultivar driving so much rich, fruity olive oil.
Swan Hill
A near-fruitless, low-pollen cultivar that saves the day where dropped fruit and allergens would be a nuisance.
Companions
How to propagate
Most olives get their start from cuttings or grafts so the young tree matches its parent, since seedlings crawl along and rarely come true to type.
Stem cuttingsModerate
Late spring to summer · 2 to 3 months to root
Cuttings are the sure-fire way to clone a named olive, since they come true to the parent every time. Grab semi-hardwood cuttings from late spring through summer, root them under mist with bottom heat, and watch them strike roots in about 2 to 3 months.
GraftingDemanding
Spring · One growing season
Grafting is the rewarding next-level move, fusing a prized cultivar onto a tough seedling or clonal rootstock. Work it in spring and a solid graft knits together and takes hold across one growing season.
SeedDemanding
Fall · Several years to fruiting
Seed is the slow, wild-card path, and the seedlings stray from the parent cultivar, so it mainly churns out rootstock. Sow in fall and settle in for a wait of several years before a seed-grown tree fruits at all.
Myths
Olives can be picked and eaten straight off the tree.
Give a fresh olive a bite and you will spit it right out, since raw fruit is savagely bitter thanks to a compound called oleuropein. It only turns delicious once you cure it in brine, lye, or salt to pull that bitterness clean out.
Olive trees never need cold weather.
They shrink from hard frost, true, but they still crave a stretch of winter chill to flower and set fruit reliably. Let the winter run too warm and you will get a thriving tree that produces barely an olive.