Olive Tree Winter Care: How Cold Can an Olive Tree Survive?

An established olive tree usually survives a short drop to about −7 to −10 °C (15–19 °F). Young trees, potted trees and fresh growth are damaged at around −5 °C (23 °F). Duration matters as much as the lowest number: one cold night is far less dangerous than several days below freezing, and wet roots in cold soil are worse than dry cold.

Olive Tree Hardiness Zones

• USDA zones 9–11: olives grow outdoors without protection.
• Zone 8: reliable in the ground with a sheltered, sunny position and hardier varieties; protect young trees in cold snaps.
• Zone 7b: possible against a south-facing wall (north-facing in the Southern Hemisphere) with winter protection; expect occasional dieback.
• Zone 7a and colder: grow in a pot and move it to shelter for the winter.

Hardier varieties include Arbequina, Picual, Leccino and Frantoio; Koroneiki is less hardy. Within any variety, older trees with thick trunks cope best.

Why Winter Cold Is Also Useful

Olives need cool winters to flower. Several weeks with nights below about 10 °C (50 °F), but above hard frost, trigger flower buds. That is why the best place for a potted olive in winter is a bright, cold but frost-free spot, not a warm living room.

Protecting an Olive Tree in the Ground

• Location: plant in the warmest spot in the garden, out of cold winds and frost pockets.
• Drainage: wet, cold roots kill more olives than cold air. Plant on a mound in heavy soil.
• Mulch: spread a thick layer of straw, bark or leaves over the root zone before winter.
• Fleece: during hard frosts, wrap the crown loosely with horticultural fleece (two or three layers for severe cold). Remove it in mild weather so the tree does not stay damp.
• Trunk: wrap the trunk of young trees with hessian or fleece.
• No autumn feeding: late nitrogen produces soft shoots that freeze.

Overwintering an Olive Tree in a Pot

Roots in a pot are exposed on all sides and freeze far sooner than roots in the ground. Options, from best to acceptable:

1. Bright, unheated room, greenhouse or porch at about 5–10 °C (41–50 °F). Ideal: the tree stays dormant and gets its chill.
2. Outdoors in a sheltered corner in mild climates, with the pot wrapped in bubble wrap or hessian, raised on feet and kept out of winter rain.
3. Indoors in a warm room only if nothing else is possible: give it the brightest window and expect leaf drop and few flowers.

Move the tree inside only when frosts below about −3 to −5 °C are forecast and bring it out again as early as possible in spring. Water sparingly in winter, only when the compost is dry a few centimetres down.

Signs of Frost Damage

• Leaves curl, turn brown or bronze and drop.
• Young shoots blacken and die back.
• Bark splits on the trunk or branches.

What to Do After Frost Damage

Do not prune straight away. Wait until late spring, when new buds show which wood is still alive. Scratch the bark with a fingernail: green tissue is alive, brown is dead. Then cut back to live wood. Olives resprout readily, even from the base after severe damage. Apply a copper spray on split bark in wet regions to reduce the risk of olive knot entering the wounds.

More Olive Tree Guides

• How to Grow Olive Trees: The Complete Guide
• Best olive tree varieties
• Growing olive trees in pots
• Growing olive trees from seed and cuttings

Frequently Asked Questions

Can an olive tree stay outside in winter?

Yes, in mild climates (USDA zone 8 and warmer). In colder areas, protect trees in the ground and move potted trees to a bright, frost-free place.

At what temperature should I bring my olive tree inside?

Bring potted trees in when frosts below about −3 to −5 °C (23–27 °F) are forecast.

Why is my olive tree dropping leaves in winter?

Usually because it is too warm and too dark indoors, too wet at the roots, or it has been hit by frost.

Will an olive tree recover from frost?

Often yes. Wait until late spring, find live wood and cut back to it; olives regrow vigorously.

Which olive tree is the most cold hardy?

Arbequina, Leccino, Frantoio and Picual are among the hardiest widely available varieties.