Of course, you should keep your eyes open for signs of pests all year round. During the winter, however, many plants are not as fit and resistant as in the summer. Therefore, aphids & Co often have it particularly easy and infest your olive tree. Although pests are annoying, they can be easily controlled if detected early. We explain to you which signs to look out for and what you can do for your olive tree in the event of a pest.
Then the aphid is at the door….
It is mainly the less robust plants that are quickly attacked by pests or pathogens. These have an easy game when the plants are weakened and thus have little to resist an attack. This can have very different causes: An unfavorable location, too little or too much water or nutrients, the wrong care… In winter, some risk factors are added. We must distinguish whether the olive tree winters outdoors or indoors.
Olives are Mediterranean plants and therefore rather not frost fans. Already from -5 degrees, the first frost damage can occur and lower temperatures are only tolerated for a short time. Therefore, wintering outside can stress and damage the tree if it is too cold. The good thing is that most pests are not active at these temperatures, but if it gets warmer again in the spring, they can attack the weakened olive tree all the more easily.
If the winter is not so severe, it is usually wet and cold in our latitudes. So rainy and really uncomfortable. The olive generally needs little water and does not cope well with permanently wet soil.
Depending on the weather and the climate conditions in your region, the tree must therefore be protected from frost and rain. Protective covers are super handy for this. However, they have the disadvantage that the olive tree can “sweat” under them. Humid weather and a little sunshine then creates a real greenhouse with very high humidity. In this atmosphere, especially fungi feel pudelwohl, which can spread on the trunk, branches and leaves. Therefore, the driest possible location and regular airing is very important. An alternative is to wrap only the tub very well and protect the trunk, but leave the tree crown free.
When wintering indoors or out, a location that is too warm is the worst thing that can happen to the olive tree. It needs winter dormancy to grow vigorously again in the spring. For this reason, a place where temperatures are around 5 to 10 degrees is necessary. In addition to heat and high humidity, the tree also does not like a location that is too dark. All this stresses the plant and until pests appear on the olive tree is then often only a matter of time.
Olive tree: recognize & drive away pests
Even despite good care, sometimes an infestation can not be prevented. Then it’s a matter of: What crawls, sticks or grows here and how does it disappear again? To that end, let’s take a look at the 5 most common pests that the olive has to contend with in the winter:
- Scale insects
- mealybugs or mealybugs
- Thick-mouthed weevil
- Spider mites
Aphids in all colors and forms
Aphids generally like it rather warm and dark. So if you have an infestation, the first thing you should do is check to see if you can find a brighter, cooler location for the olive tree.
The best known aphids are also the least problematic. Although they usually appear in large groups, they are very easy to see and can be easily removed. The small animals are usually green or black and have a proboscis with which they suck the plant sap from leaves and stems. They like to hide on the undersides of leaves. If your sapling is not too big yet, but the infestation is quite severe, it may make sense to simply shower off the whole plant. Otherwise, you can also gently wipe the leaves with a damp cloth. Spraying with a nettle decoction is also helpful. This can also be made from dried leaves, since fresh nettles are rather scarce in winter.
- scale insects
These nasties are not so easy to detect and remove. The so-called cup scale aphids hide under oval shells of different sizes, where they also suck the cell sap from the plant. The animals can be wiped off, but this may spread their eggs even further on the plant. You should therefore use a cotton swab soaked in methylated spirits, then the animals will die. It is also useful to spray the plant afterwards. For this purpose you can use, for example, nettle decoction or solutions with neem oil. You can also buy oil-based preparations that are gentle on plants.
Effective, but not particularly natural, are special control agents that are added directly to the irrigation water and absorbed through the roots. The aphids absorb the toxic substances through their cell sap. However, the use of such insecticides is only recommended in the case of a really stubborn infestation that you cannot control in any other way.
These little animals live up to their name, as they are covered with a woolly layer. They belong to the scale insects and can be controlled in the same way. However, their eggs are usually found in the plant soil. Therefore, in case of a heavy infestation, you should resort to means from the specialized trade to quickly contain the problem. Repotting in the spring is then advisable.
An effective do-it-yourself remedy is a mixture of water and oil. For a half liter you need:
- 400 ml water
- 100 ml oil (preferably rapeseed oil)
- 2-3 squirts of dishwashing liquid
Spray the plant thoroughly. The pests cannot breathe under the oil film and die.
- thick-mouthed weevil
If you bring your olive into winter quarters and you notice feeding marks on the leaves, they may possibly be from the thick-mouthed weevil. This beetle is not active in winter, but its larvae overwinter in the soil. Threadworms, so-called nematodes, which can be bought in specialized shops, help against them. So if you find new feeding traces in spring, it may make sense to use nematodes or repot the olive.
- spider mites
Spider mites like it dry and are therefore more of a danger if your olive winters indoors. These tiny creatures form fine webs on the underside of the leaves. Spraying with nettle decoction or mixtures with oil will also help against them.
Keep your eyes open
We hope, of course, that pests are scarce on your olive tree. To keep it that way, special attention is needed, especially in winter. Visit your olive tree regularly and see how it is doing. Prevention is still the most effective measure against pests. This means that in winter you need to know the needs of the olive tree and take care of them. A bright and cool location, rather dry soil, low humidity and suitable protection from frost are important. Whether indoors or outdoors, your olive will thank you if you get it through the winter well.
I have 30 years of experience and i started this website to see if i could try and share my knowledge to help you.
With a degree a Horticulture BSc (Hons)
I have worked as a horticulture specialist lead gardener, garden landscaper, and of course i am a hobby gardener at home in my own garden.
Please if you have any questions leave them on the article and i will get back to you personally.