Olive trees are among the most popular plants in Mediterranean garden projects. In order to bring the olive tree safely through the cold season, you have to consider a few points regarding the winter of the olive tree.

In a nutshell

  • Depending on the region, olive trees can be overwintered outdoors
  • north of the Alps, wintering indoors is generally preferable
  • the hibernation period starts at temperatures of -10°C at the latest
  • planted specimens need good protection from cold and wet over the winter
  • Olive trees that hibernate indoors require little care during the cold season

Pot plant or free range?

Overwintering the olive tree is one of the most demanding care measures for Mediterranean plants. In order not to expose Olea europaea to cool temperatures, a few points must be considered when choosing the location. Since olive trees are Mediterranean plants, it is usually too cold for them north of the Alps. Although the plants can withstand temperatures of down to -10°C, there are numerous regions in Germany that are significantly colder. If this is the case for you, you should never consider overwintering your olive trees outdoors. Despite the temperate climate, there are some parts of the country where the trees can be kept outdoors all year round:

  • wine regions
  • areas on the Lower Rhine
  • southwestern Baden-Württemberg (e.g. Freiburg)

These are mild winter areas, so they are made for the olive trees. In these, olive trees winter quite well, although winter protection is still needed. However, you don't have to worry as much about possible frost damage if you consider the appropriate temperatures in the region.

Notice: Always consider the minimum possible temperatures in your region, rather than the average, before planting the crop. Long periods of frost do not pose a problem for the olive tree, while just one day below -10°C can take its toll.

time

Wintering timing is extremely important for olive trees. Only if the tree moves to winter quarters early enough or is provided with winter protection will it survive the cold season without problems. From when the plant is overwintered depends exclusively on the temperatures at the end of autumn or early winter. The months of November to December are recommended, before the night-time temperatures reach -10°C. Ideally, the olive tree is transported to the winter quarters or packed from -5°C to -7°C. It remains in this state until March or early April, when it gets warmer again at night.

Notice: Depending on where you live, the timing may be earlier or later. For this reason, check the weather forecast as often as possible to determine a suitable day for the start of the wintering period.

Tub specimens: ideal winter quarters

If you have decided to winter the olive tree indoors, you need to take the right precautions. The biggest advantage of this variant is the easy-care nature of the olive tree. Olea europaea is quite undemanding over the winter if the location during the cold season meets the requirements of the plant. Select a location in the house for the olive tree that has the following characteristics:

  • bright
  • avoid direct sun
  • Temperature: 5°C to 10°C

Rooms that are not used that often, such as guest rooms, conservatories, hallways, garages and greenhouses, which can be heated, are particularly well suited as winter quarters. The chosen location should have a possibility of ventilation, since the olive trees need fresh air on a weekly basis. This way they don't get too warm and they tolerate the fresh air better. Overwintering in the cellar at around 5°C is also possible. Expect your olive tree to shed its leaves as basements are just too dark. A plant lamp can help in this case. You should observe the following care measures over the winter:

During the winter in the cellar, the olive tree often loses its leaves.
  • do not fertilize
  • water as needed
  • check the substrate with a thumb test

From March, get the plant used to the sun more and more. To do this, carefully place the olive tree outside in a spot that is exposed to the sun.

Tip: If the foliage turns yellow over the winter, you are giving the plant too much water in the winter quarters. Be sure to reduce the amount of water so that the plant can recover.

Overwinter outdoors

If it is possible for you to overwinter the olive tree outdoors, you must ensure good winter protection. This applies to planted and potted specimens that are not brought indoors over the winter. The location itself doesn't really need to be adjusted, although you should protect trees from direct sun as much as possible. The only important thing is that it is protected from wind and precipitation. Rain and snow are not ideal for the olive tree, as it is very sensitive to moisture during the winter. A protective roof is therefore never wrong. The trees receive the following winter protection:

  • Wrap the crown in garden fleece
  • only necessary if there is a risk of frost
  • protect the plant disc
  • use bark mulch, straw or brushwood for this

Above all, freshly planted specimens need protection for their plant disc, as they are even more sensitive to soil temperatures. If, on the other hand, it is a potted plant, also wrap the pot in garden fleece and place the pot on a styrofoam plate. In this way, the sensitive roots are protected from the cold. On frost-free days, water the tub olive trees a little.

frequently asked Questions

What does acclimatization mean in olive trees?

Olive trees get used to their location over time. For this reason, young specimens acquired in Central Europe are better suited for the domestic winter than specimens imported from the Mediterranean region. Older trees in particular, which are used to the temperatures of the Mediterranean, have problems outdoors with the climate north of the Alps.

Can olives be acclimated to the cool temperatures more quickly?

Yes, if planted out in the garden early enough in the year. Spring is ideal for this, when the night-time temperatures no longer fall below -10°C. In this case, the trees have until the end of autumn to get used to the climate. If you only receive your olive tree in summer, it will overwinter indoors, even in regions with mild winters.

Can young olive trees be overwintered outdoors?

No, you should always overwinter young olive trees indoors for the first few years. They only get used to the climate over time and can be planted outdoors when they are adults with extensive winter protection. In this way you prevent possible problems that could arise from the cold temperatures.

Are there hardy olive varieties?

Hardy olive varieties withstand longer periods of frost down to -10°C much better than others, but should not be exposed to harsh winters either. Suitable varieties include, for example, 'Forma Toscana' from the region of the same name in Italy or the Spanish 'Manzanilla Cacerena'.

What is eye spot disease all about?

Olive trees overwintering indoors are rarely attacked by the fungus Spilocaea oleagina, which can be recognized by yellowed leaves with brownish spots. Be sure to reduce the amount of water to curb the fungal attack and carefully remove the affected leaves. Dispose of them in the household waste. In addition, it helps to give the olive tree more light.

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