It might come as a surprise, but what is most fatal to olive trees in winter isn’t the cold – it’s moisture.
If the cold sets in gradually and the air is dry, olive trees are hardy down to 10 to 17°F (-8 to -12°C) and have been known to survive temperatures as low as 0 to 4°F (-15 to -18°C).
But if moisture and water join the game, all is lost.
- Here is our page on growing olive trees
- What freezing does to an olive tree
- Why olive trees need cold weather
Let us see how olive trees can be protected during winter
You’ll have to proceed differently depending on whether your olive trees grow in the ground or in a pot or container.
Olive trees in the ground
If you live in the South, you shouldn’t worry, your olive trees will surely resist winter conditions.
However, if you live North or in a region where it rains a lot during winter, you must take a few steps to protect your olive trees.
- With garden soil, create a slope around the base of your olive trees so that water would not flow near their roots.
- It is important to evacuate water as far as possible from your olive trees in winter: nothing is more dangerous to your tree.
- Stop all irrigation after having harvested your olives.
- Don’t fertilize after the harvest. Specifically, don’t add nitrogen-rich fertilizer in fall or autumn.
- Mulch the base of the olive trees to protect roots from freezing. Using organic plant-based mulch is ok because it would only break down towards spring.
In spring, after freezing is over, you can start irrigating or watering again. This will help your olive trees recover from any wounds due to frost.
Olive trees in pots or containers
Once again, if you live in the South, where temperatures never drop below 20°F (-6 or -7°C), nothing much is needed.
- Place your olive trees in the sun.
- Water only if the soil is completely dry, and then only small amounts of water.
- It’s normal for the tree to lose some of its leaves over the dormant period, about 1/3rd of them will fall in winter.
However, if you live further North,
- Best is to place your olive trees in a cool and well-lit place where it never freezes.
- The winter cold in these areas is also very moist, so you must do your utmost to protect your olive trees from moisture.
If you cannot bring your olive trees indoors,
- Never bring your olive trees indoors in winter.
- Outside, bring them as close as possible to a window so that they may benefit from the warmth of the house.
- Mulch the base of your olive trees to protect them from the cold.
- Wrap the pots with a thick cover, and avoid letting rain fall in.
- Cover with horticultural fleece, keeping buffer space all around so no leaves touch it. Again, the goal here is to avoid condensation touching the plant since it is a source of moisture.
- Water as little as possible, and then only if no rainfall reaches the plant.
Smart tip about winterizing olive trees
You’ll increase hardiness of your olive tree in winter by protecting it from wind. Set a lattice up on two sides, forming a corner that will cut the worst of colds winds off.