How winter hardy is an olive tree? A healthy olive tree can tolerate cold and light to moderate frost surprisingly well. However, this does not mean that every olive tree will survive every Dutch or Belgian winter without protection. Prolonged frost, cold wind, wet roots and a completely frozen root ball can cause damage.
How much frost and cold a olive tree can tolerate depends, among other things, on the age and condition of the tree, the location, the soil, the duration of the frost and whether the tree is in a pot or in the ground.
In this article you will read how winter hardy an olive tree is, how many degrees of frost an olive tree can tolerate, when you need to protect it and what you can do in case of frost damage.
How winter hardy is an olive tree in short?
The Olea europaea is fairly winter hardy. A healthy and well-established olive tree can normally tolerate a few degrees of frost well. At temperatures around -7 to -10 °C the risk of damage increases, especially when the frost lasts for several days. At even lower temperatures, serious damage to leaves, branches, trunk and roots can occur.
However, there is no exact temperature at which every olive tree gets damaged. The conditions around the tree are at least as important as the temperature itself.
| Question | Answer |
|---|---|
| Is an olive tree winter hardy? | Yes, a healthy olive tree can tolerate light to moderate frost. |
| How many degrees of frost can an olive tree have? | A few degrees of frost are usually not a problem. Around -7 to -10 °C the risk of frost damage clearly increases. |
| Should an olive tree always be wrapped? | No. Protection is especially advisable during prolonged or severe frost. |
| Is a potted olive tree winter hardy? | Yes, but the root ball is more vulnerable because a pot can freeze completely more quickly. |
| Can an olive tree recover from frost damage? | Often yes. If the trunk, roots and sufficient wood are still alive, the tree can sprout again in the spring. |
Want to see trees that are suitable for our climate right away? Then check out our range of winter hardy olive trees.
How winter hardy is an olive tree in severe frost?
This is one of the most frequently asked questions about olive trees. However, there is no temperature limit that is the same for every tree. A healthy and well-established olive tree can usually tolerate light frost. Temperatures of a few degrees below zero usually do not pose an immediate problem.
When temperatures drop further, the risk increases. Around -7 to -10 °C you need to be extra alert, especially when these temperatures occur for several nights in a row.
In severe frost, damage can occur to:
- leaves;
- young shoots;
- thin branches;
- thicker branches;
- the trunk;
- the root ball.
The longer a cold period lasts, the greater the risk. A short night with, for example, -7 °C is after all something completely different from several days during which it also remains frozen during the day.
Can an olive tree withstand night frost?
Yes. You do not need to act straight away at the first night frost of autumn. A healthy, well-kept olive tree can usually cope well with normal night frost in the Netherlands and Belgium. Temperatures of, for example, -1, -2 or -3 °C for a few hours are normally no reason to wrap up a large olive tree completely.
A short spell around -5 °C is usually no reason to wrap a healthy, well-established tree straight away either. If the tree is in a small pot, fully exposed to cold wind, or several days of frost are forecast, extra protection can be sensible.
So look at the whole forecast: how many hours it will freeze, how many frost nights are expected and whether it gets above zero during the day.
Why is not only the temperature important?
When talking about winter hardiness, only the number of degrees of frost is often considered. In practice, many more circumstances play a role.
Think, for example, of:
- the duration of the frost;
- the daytime temperature;
- cold easterly wind;
- humidity;
- amount of precipitation;
- soil drainage;
- location;
- age and condition of the tree;
- full ground or pot;
- size of the pot;
- shelter around the tree.
A healthy olive tree in a sunny and sheltered place with well-draining soil can withstand a cold period better than a weakened tree that is wet and completely exposed to the wind.
The right location is therefore important. Also read our planting tips and information about the right location.
Is an old olive tree better winter hardy than a young olive tree?
A large, healthy and well-established olive tree usually has more reserves than a small young tree. The thicker trunk and larger root system can help to better absorb temporary cold conditions. This does not automatically mean that every old olive tree is completely winter hardy. Even with old olive trees, location, drainage and protection during exceptionally cold periods remain important.
In addition, a newly planted large tree can temporarily be more vulnerable because the root system still has to adapt to the new location.
How winter hardy is an olive tree in the ground?
An olive tree in the ground has an important advantage during severe frost: the soil usually freezes less quickly and less completely than the earth in a loose pot.
Because of this, the roots are often better protected against extreme temperature fluctuations. The condition is, however, that the soil is well-draining.
Olive trees do not like prolonged wet roots. Especially in winter, a combination of a lot of moisture and frost can cause problems. Do you want to plant your tree in the garden? Then also read whether you can plant an olive tree in garden soil.
Is a potted olive tree winter hardy?
A potted olive tree can easily overwinter outside, but requires extra attention during cold periods.
The biggest difference with a tree in the ground is below the ground. With an olive tree in a pot, the root ball is exposed on multiple sides to the outside temperature. Because of this, the root ball can freeze completely more quickly during prolonged frost. The smaller the pot, the faster this can happen.
Therefore, during a severe frost period, it is wise to look not only at the crown and trunk, but also at the roots.
Why are wet roots a risk in winter?
An olive tree originally comes from a climate with relatively dry conditions. The roots therefore do not like prolonged wet, poorly draining soil. In the Netherlands and Belgium, much more precipitation falls in the autumn and winter than in many Mediterranean regions.
When excess water cannot drain away properly, the roots remain wet for a long time. In combination with cold, this can deteriorate the condition of the tree. Good drainage is therefore one of the most important points of attention when keeping an olive tree in our climate.
Make sure that:
- excess rainwater can drain away;
- drainage holes in pots are not clogged;
- a pot does not stand in a layer of water for a long time;
- the soil is sufficiently airy and permeable;
- you do not water unnecessarily much during cold and wet periods.
Are you in doubt about watering? Then check how much water an olive tree needs.
When should you protect an olive tree against frost?
You do not need to completely wrap an olive tree for every night frost. A healthy olive tree can normally tolerate light frost. Wrapping completely too early or for a long time is therefore usually not necessary.
Extra protection becomes especially interesting when:
- severe frost is predicted for several nights in a row;
- the temperature goes towards about -7 to -10 °C or lower;
- it also remains frozen during the day;
- a combination of frost and hard cold wind is expected;
- the tree is still young or newly planted;
- the olive tree is in a relatively small pot;
- the tree is in a very open and unprotected place.
So do not only look at the lowest temperature of one night, but at the complete weather forecast.
Is frost forecast? First check how severe and how long it will be. With a few degrees of night frost you usually need to do very little.
How do you protect an olive tree against frost?
During a cold period, you can protect different parts of the tree.
Protect the root ball
With potted olive trees, the root ball is one of the most important points of attention. You can insulate the pot during a severe frost period with suitable insulating material. With this, you limit how quickly the cold penetrates deep into the root ball.
Place a pot in a sheltered place if possible and prevent it from standing in water for a long time.
Protect the crown
During severe or prolonged frost, the crown can be temporarily protected with a breathable winter protection material, such as winter fleece. Preferably use material that allows air and some moisture transport.
Protect the trunk
In exceptionally cold conditions, the trunk can also be extra protected, especially with younger trees or trees in a very open location.
Choose a sheltered position
An olive tree next to a wall, fence or other sheltered part of the garden is often more favorable than the same tree in the middle of an open area. Especially cold wind can enhance the effect of winter conditions.
Should you wrap an olive tree the whole winter?
No. It is usually not necessary and also not desirable to leave an olive tree completely wrapped from autumn to spring. Protection is especially intended for actual cold periods.
When the weather gets milder, the protection around the crown can be removed again. This way, the tree gets enough light and air and you prevent a prolonged moist microclimate around the leaves.
So protect specifically when the weather conditions call for it.
Can an olive tree withstand snow?
Snow itself does not automatically mean that an olive tree gets damaged. A thin layer of snow during light frost does not have to be a big problem.
However, a heavy amount of wet snow can cause weight on the branches. Especially a full crown can temporarily be heavily burdened by this.
Therefore, check the tree after heavy snowfall and carefully remove heavy snow when branches bend strongly. Do not pull or hit hard against frozen branches. Frozen wood and leaves can be more vulnerable.
What does cold wind do to an olive tree?
A cold, dry wind can be extra burdensome during a frost period. Leaves lose moisture, while the roots from a cold or frozen soil can hardly take up new water. Because of this, leaves can dry out and turn brown.
A sheltered location therefore helps not only against the lowest temperature, but also against drying out by winter wind.
Especially olive trees that stand completely free on an open terrace or in an open garden deserve extra attention during severe winter conditions.
How do you recognize frost damage on an olive tree?
Frost damage is not always immediately visible. Sometimes it only becomes clear after a few days or weeks which parts of the tree are damaged.
Possible signs are:
- brown leaves;
- dried leaves;
- leaf fall;
- dark or damaged young shoots;
- dead ends of branches;
- cracks or damage in young wood;
- branches that no longer sprout in the spring.
Leaf loss does not automatically mean that the whole tree is dead. An olive tree can react quite a bit to difficult conditions and then sprout again from healthy wood.
Do you see discoloration on the leaves? Then also check our explanation about brown, curling or black leaves on an olive tree.
Can an olive tree recover after frost damage?
Yes, that is possible. A special property of the olive tree is that it can sprout again from living wood. A tree that has lost a lot of leaves after the winter therefore does not have to be lost immediately.
Give the tree time to recover in the spring first. When the temperatures rise, it becomes clearer which branches are still alive and where new shoots arise.
Therefore, do not immediately cut away all parts that look less beautiful after a frost period. Want to know when you can expect new growth? Then read when an olive tree sprouts again.
When do you know if an olive tree has survived the winter?
Immediately after a cold period, this is not always easy to judge. Leaves can turn brown or fall off, while the branches and trunk are still alive. Only when spring begins and the temperatures rise, it becomes clear how the tree reacts.
New buds and shoots are a good sign. Sometimes an olive tree first sprouts on certain parts of the crown. With heavier damage, new shoots can arise lower on the tree or from the base.
So have patience when an olive tree looks bare or damaged after the winter.
Can you let an olive tree overwinter inside?
That is possible under certain circumstances, but a warm living room is usually not the ideal overwintering place.
An olive tree actually benefits from a cooler period in the winter. When you want to temporarily move a tree because of extreme circumstances, a light, cool and frost-free space is more suitable than a warm living room.
With large olive trees, moving is of course often not practical. Then protection at the existing location is usually more logical.
A well-placed and healthy olive tree in the Netherlands can simply stand outside, provided you take measures in time during exceptional weather conditions.
Does pruning have an effect on winter hardiness?
A healthy crown contributes to a healthy tree. However, it is wise to avoid heavy pruning just before a cold winter period.
After heavy pruning, pruning wounds arise and new growth can be stimulated. Young, soft shoots are more vulnerable to frost than well-cured wood. Therefore, plan larger pruning work at a suitable time.
Want to know when you can do this best? Then check out our extensive explanation about pruning an olive tree.
Does nutrition have an effect on winter hardiness?
A healthy olive tree can generally tolerate difficult conditions better than a weakened tree. Good care during the growing season therefore indirectly contributes to a strong tree.
That does not mean that you should give extra much nutrition just before winter. The goal is precisely a healthy, balanced growth during the season.
Want to take good care of your tree all year round? Then check out our complete guide about taking care of an olive tree.
Common mistakes with olive trees in winter
At Olivera Garden we regularly get questions about olive trees during frost periods. A number of misunderstandings often come up.
An olive tree cannot withstand frost at all.
That is not true. A healthy olive tree can tolerate light to moderate frost. The risk increases especially with severe and prolonged frost.
An olive tree must be completely wrapped the whole winter.
That is usually not necessary. Protect especially when actually a severe or prolonged frost period is expected.
Only the crown needs to be protected.
With an olive tree in a pot, the root ball is especially important. A pot can freeze completely much faster than the soil in the full ground.
Brown leaves after frost mean that the tree is dead.
Not necessarily. The leaves can be damaged while branches, trunk and roots are still alive.
Giving a lot of water helps against frost.
No. Prolonged wet roots can actually cause problems. Especially make sure of good water management and drainage.
One temperature determines whether an olive tree is winter hardy.
This is also not true. Duration of the frost, wind, moisture, location and condition of the tree are at least as important.
Practical winter checklist for an olive tree
Do you have an olive tree standing outside? Then check especially the points below during the winter.
- Is the tree standing in a sunny and as sheltered a place as possible?
- Can excess rainwater easily drain away?
- Are the drainage holes of the pot free?
- Is the pot not standing in a layer of water for a long time?
- Is prolonged or severe frost predicted?
- Is the tree in a pot that can freeze completely?
- Is extra insulation around the pot necessary?
- Is protection of crown or trunk necessary?
- Can winter protection be removed again after the frost period?
- Are new buds or shoots visible after the winter?
With these points you significantly reduce the chance of problems.
Location and size make the difference
When choosing a tree, don't just look at its height and appearance. Its health, trunk shape, crown, and overall quality are at least as important.
For the Dutch and Belgian climate, the final location is also an important factor. A healthy tree in a sunny spot with well-draining soil has a much better chance of survival than an olive tree that is left with wet roots in a cold, exposed location for extended periods.
The size and planting method also play a role. A large olive tree in the ground requires a different approach during a cold spell than a smaller tree in a pot.
That is why we advise not to panic automatically at the first night frost, but to remain alert when a prolonged or severe frost period is forecast.
Conclusion
An olive tree is reasonably hardy and can generally tolerate light to moderate frost well. A few degrees of frost usually do not pose a problem for a healthy, well-established tree.
When temperatures drop towards -7 to -10 °C, the risk of frost damage increases. This is especially true when the frost lasts for several days, continues during the day, or the tree is exposed to harsh, cold winds.
Therefore, do not look exclusively at a single minimum temperature. The location, drainage, duration of the frost, condition of the tree, and whether it is in a pot or in the ground together determine how well an olive tree will withstand winter.
For potted olive trees in particular, the roots deserve extra attention, as a root ball in a pot can freeze completely more quickly.
A hardy olive tree for your garden?
Would you like a Mediterranean look in your garden without having to worry immediately about every light night frost? Then take a look at our range of hardy olive trees or view our complete selection of olive trees.
At Olivera Garden, you will find young specimens up to large olive trees, sourced directly from specialist nurseries.
This way, you can choose a tree that is not only beautiful, but can also serve as a Mediterranean eye-catcher in your garden for years to come, given the right location and care.
For example, take a look at the Olea europaea Lorc 200 cm, the Olea europaea Cultivo 230 cm, or a compact 160 cm standard olive tree.
Frequently asked questions about the hardiness of olive trees
How many degrees of frost can an olive tree withstand?
A healthy, well-established olive tree can generally withstand a few degrees of frost. When the temperature drops towards approximately -7 to -10 °C, the risk of frost damage increases. The duration of the frost, wind, moisture, location, and condition of the tree also determine how much cold an individual olive tree can withstand.
Can an olive tree withstand night frost?
Yes. A healthy olive tree can usually cope well with a few degrees of night frost. A short night of light frost is rarely a problem. The risk increases when the temperature drops further or the frost lasts several days.
Should I wrap my olive tree at -5 °C?
A healthy, well-established olive tree does not automatically need to be wrapped completely during a short spell around -5 °C. If the tree is in a small pot, fully exposed to cold wind, or several days of frost are forecast, extra protection can be sensible.
Can a potted olive tree overwinter outdoors?
Yes, a potted olive tree can overwinter outdoors. However, the root ball is more vulnerable than that of a tree in the ground, because the pot can freeze completely more quickly. During severe frost, it may therefore be wise to provide the pot and, if necessary, the crown with extra protection.
What should you do if an olive tree has frost damage?
First, wait to see how the tree reacts in spring. Brown leaves and leaf loss do not automatically mean the tree is dead. If the trunk, roots, and parts of the branches are still healthy, an olive tree can grow new shoots. Therefore, do not prune damaged parts severely immediately after the first cold spell.
Can an olive tree stay outdoors all year in the Netherlands?
Yes, many healthy olive trees can stay outdoors all year in the Netherlands. A sunny, sheltered location, good drainage, and appropriate protection during exceptionally severe or prolonged frost are important.
