Hardly any other plant brings as much Mediterranean flair to German regions as the olive tree. While it thrives outdoors in the Mediterranean region, it has rarely been found in pots in Central Europe in the garden or on the balcony all year round. This is not least due to the fact that the real olive tree does not easily survive the local winter. It is not difficult to let the olive trees in pots overwinter outside in the icy season. The plant expert explains what is required for this.

Olive trees in the first years of life

The olive tree plants grow quite slowly. If they are planted in a pot or tub, they can usually be easily moved from outside to winter quarters in the first few years of life. With increasing size, the pot/tub circumference also increases and the weight increases accordingly. At some point it will be too heavy to transport safely from A to B.

For overwintering, this means that younger, smaller olive trees in pots can easily overwinter in frost-free locations. In this case, no special precautions need to be taken. Larger specimens on terraces and balconies can then no longer be relocated and should be provided with winter protection so that they do not freeze to death.

tip: If you place a special saucer with wheels under the pot from the start, heavy specimens can be moved to a suitable winter quarters much more easily.

Overwinter in winter quarters

The best winter protection is to move to winter quarters. A heated apartment is not suitable for this, because in winter the real olive tree in the pot with the botanical name "Olea europaea" must be cool but frost-free. With the temperatures in an apartment, he could not keep his hibernation and gather strength for the next growing season.
If you stick to the following points, the olive tree will come through the winter unscathed:

  • Optimum temperatures around 10 °C
  • Bright location without direct sunlight
  • Ideal locations in unheated conservatories, corridors, greenhouses or in garden houses by the window
  • Warm rooms or the dark basement are not suitable as winter quarters
  • Only bring in the olive tree shortly before a longer frost
  • Relocate only young olive trees to winter quarters before the onset of frost
  • Ventilate winter quarters regularly
  • Slowly reduce the amount of water to a minimum (otherwise the leaves will fall off)
  • Only water occasionally during the winter season (there is a low water requirement in cool temperatures)
  • If the leaves fall off, make the olive tree lighter and/or slightly increase the amount of water again (chances of survival decrease)
  • Do not fertilize in winter
  • Slowly get used to the outdoors in March - but there must be no frost (avoid direct sunlight)
  • From outside temperatures around freezing point, he can stay outside on the balcony or terrace

Overwinter the olive tree in a bucket outside

If no suitable winter quarters can be found or if the effort is too much for you, the Olea europaea can also spend the winter outdoors under certain conditions. The basic requirement is that the average temperatures do not fall too low and that protection against the cold is provided.

Hardness zone classification of the cold

The regions are divided into so-called winter hardiness zones using permanent statistics. These roughly predict where maximum temperatures can be expected in winter. The classification includes a total of eleven zone areas and extends from Z1 to Z11. For wintering outdoors, whether in a bucket or in the garden, your region should have a winter hardiness zone of at least Z8. That means: maximum average minus temperatures of around 12 °C. Find out in good time before the onset of winter which zone you are in if you cannot make a realistic assessment based on the experience of the past few years.

Winter protection for potted plants

Proper protection against the cold in combination with a suitable location ensures that the olive tree does not freeze to death and continues to grow healthily next spring. Winter protection is important because plants cultivated in tubs are otherwise much more at the mercy of the cold than specimens planted in the garden bed. The cold reaches the roots much more intensively through a bucket than through thick layers of soil, which usually only freeze on the surface. If the roots freeze or suffer extensive damage, the olive tree usually does not survive the winter season.

Measures for wintering outdoors

When overwintering the real olive tree, the following measures should be taken for ideal protection against the cold:

  • Start of winter protection at the latest when permanent frost is expected
  • Since frost kills many pests, always wait for the first frost before taking any precautions to protect against the cold
  • Place the bucket on an insulating base - for example styrofoam, wood and thick cardboard
  • Choose a location that is sheltered from the wind, for example under a roof or on heat-dissipating walls
  • Cover the pot with air-permeable jute or plastic foil (holes in the plastic foil allow condensation to drain)
  • Cover the substrate with a thick layer of straw, pine needles, brushwood or leaves
  • Surround the Olea europaea with brushwood, coconut or straw mats from the bottom of the stem to the crown
  • Sufficient light must still be able to shine on the plant from above
  • A location with a low roof is therefore not suitable (e.g. a garbage can shelter)
  • In very dry winters you should water occasionally (only on frost-free days)
  • Don't fertilize
  • Protection against the cold can be removed when the outside temperature no longer permanently falls below -7 °C

tip: With an electric root heater from a specialist shop, even colder sub-zero temperatures can be survived. For the green area, a wrapped chain of lights helps on particularly cold days, which emits heat when switched on.

In addition, the following should be observed:

  • It is better to water olive trees less than too much - otherwise root rot threatens to destroy the plant
  • Allow the substrate to dry slightly before the impending frost - then it freezes less
  • Fertilize your olive tree with patent potash by mid-September at the latest - this strengthens the plant for the cold season

Category:

Garden plants