In internet forums as well as in some gardening guides it is repeatedly claimed that olives can hibernate outdoors without protection. This statement is simply wrong, because olives are Mediterranean plants and do not tolerate (long-lasting) frost.

Overwinter olives properly

However, short-term frost does not harm older olive trees in particular, which they often know from their homeland. Long-lasting and deep frosts, however, result in the tree dying. In particular, olives kept in pots and young trees should therefore be comprehensively protected if they are to overwinter outdoors. It is best to set them up in a bright but not too warm place - temperatures from just above freezing point to around 10 °C are ideal for the rest phase. But even venerable solitaires will not survive the winter without the appropriate protection.

How useful are heaters?

Experienced gardeners will advise you to equip outdoor olives in winter not only with a thermal cover, but also with a heater for the roots as well as for the trunk. In winter, the roots are particularly endangered, because if they freeze to death due to prolonged ground frost, the entire tree will die. On the other hand, if they are preserved, the olive will usually sprout again. Special root heaters are therefore quite useful, as they protect the most sensitive parts of the olive from the cold. There are special plant heaters for the roots, the trunk and the crown.

When plant heaters should be used

  • Plant heaters are only required in very cold winters with prolonged periods of frost
  • at temperatures around freezing point and just below, wrappings are sufficient
  • make sure that the whole tree is heated evenly so that there is no temperature gradient (e.g. between heated roots and cold crown)
  • also heat the sides evenly

What speaks against plant heating

But beware: plant heaters not only have advantages, which is why they should only be used when temperatures are really low and / or for longer periods of time. Olives go into the vegetative phase at temperatures of around five degrees Celsius, which in turn can lead to dehydration in the dead of winter. Therefore, plant heaters should never be set too warm, as this disturbs the plant in its winter dormant phase. The heat also attracts pests such as mice, but fungi and scale insects also feel very comfortable on heated plants. In addition, there is the problem with many heaters that they only heat on one side and some parts of the plant remain unheated. In such a case, warming wraps are a better choice as they provide even heat.

tips and tricks

Wrap your olive with a commercially available outdoor chain of lights, then wrap the trunk and crown with a thick fleece material. You can cover the roots with a thick layer of bark mulch (at least 25 centimeters!) and with foil to protect against moisture.

Category:

Trees