An olive tree in the German household – not necessarily a matter of course, at least not for the olive tree that would rather enjoy the southern sun. If he has then (discontentedly) decided to make do with the German sun, he is now banished to a dark cave even in winter – that is finally too much, and the most common reason for an olive tree losing leaves. Other causes require detective work, we’ll get you on the track.
Table of Contents
The most likely cause
It is very often complained that olive trees cultivated in our country lose leaves. An overview of the reports shows a very clear trend in the causes: the olive tree ( Olea europaea ) begins to shed its leaves at its winter location, more or less quickly.
Behind this is almost always clearly incorrect wintering. First, a few words about wintering:
1. In winter, an olive tree that has been outside during the summer is moved indoors. In most cases it is simply too dark for him there. In its homeland (Middle East, South Africa, Mediterranean region for a long time) the light already shines with a completely different intensity in summer. In winter, behind window panes, the light intensity decreases again by powers. That’s not enough for the olives anymore. They start shedding lots of leaves in self-defense.
2. This “self-defence” is even more stimulated by overly warm winter locations. Here the olive tree cannot switch to the dormancy that would be appropriate for the cloudy environment; in order to slow down its metabolism, it would need a rather cool environment .
3 . The olive tree is often watered too much at this winter location that is too warm . If the olive tree gets too little light, it will definitely slow down its metabolism. This is in the nature of photosynthesis: During photosynthesis (in short: plant nutrition) the plant converts low-energy substances (carbon dioxide = CO2 and water = H2O) with the help of light energy into high-energy substances from which it feeds. Too little light means hunger for the plant, if it doesn’t slow down its metabolism, it will starve.
Correct hibernation
Correct overwintering of the olive brings a remedy for all three causes of leaf fall.
Olive trees should also spend the winter outdoors if possible. Yes, you heard that right, outdoors all year round, on the terrace or on the balcony, even in the snow. Olives are trees, not houseplants, and they do need a cool period in winter. They also experience this in their natural habitats on the Mediterranean.
They tolerate a few degrees below zero without any problems, and winter protection takes care of the rest. The younger the tree, the more caring:
- Towards the end of the vegetation period, give an extra portion of Kalimagnesia, this allows fresh shoots to lignify and thus increases winter hardiness
- Better several small portions than one at a time, and not too much (read the manufacturer’s description)
- If it can get really cold, put a styrofoam plate under the olive tree
- Cover the root area with mulch, leaves, straw or similar, weigh down with stones
- Wrap the trunk and main branches with mats made of jute, sisal, coconut or straw (permeable to air, no plastic).
- Wrap crown with winter protection fleece, loose but windproof
- If it could get cold, you can incorporate an outdoor string of lights into the cases
- It is turned on in the evening (looks nice) and emits exactly the few degrees of heat that protects the tree down to around -15 °C
- Please let it burn for a few hours beforehand and measure the temperature, not every chain can be trusted
- Remove snow from the root area to allow the sun to reach
- Radically reduce supply, no fertilizer and minimal water
The tip for the olive tree in the holiday home in northern Finland would then be a tent with electronically controlled heating.
Hibernate olive trees warmer
If you don’t have a terrace or balcony where the olive tree could spend the winter outside, a cool adjoining room with a temperature between 5 and 10 °C would be the alternative quarters, even here with a very reduced supply. This cool side room can also be a bright stairwell. After consultation, the neighbors will certainly have sympathy and approve this location.
If you have no choice but to cultivate the olive tree in the normal living room due to a lack of cool adjoining rooms, this is really the most suboptimal option. Olive trees are tough and should usually survive, but if you’ve just been gifted a magnificent old olive tree, you might want to consider using a wintering service.
The following applies here: the supply must not be completely discontinued. The warmer the olive tree is in winter, the more water it needs. It is not fertilized in a normally bright (= too dark) location during the winter season. He should, so to speak, go “semi-quietly”. This will then usually lead to the leaves on the olive tree turning yellow, curling up and/or falling off. As a rule, however, the olives should sprout again in the spring. Not a dream life for an olive tree, new leaves form completely every spring, the alternative would be artificial light supply – but even then the olive tree lacks the winter rest. Working around the clock all year round without a break will probably not last forever. If you can’t think of anything that can give the olive tree a winter break,
What else could it be?
Olive trees are at home in significantly warmer environments. This has some typical consequences for treatment in culture in this country, non-observance of which (especially in combination with the unfavorable conditions that are usual in our country) can result in leaf fall:
- Olive trees are more used to drought, because emerging wet dries up quickly in the warm
- Keeping too moist can lead to leaf fall
- Olive trees are used to normal, real, well-drained soils that certainly don’t store too much water in Italy, Greece
- Anyone who buys their potting soil in stores or takes garden soil and does not practice proper soil care in the garden often cannot offer it
- Purchasable substrate is substrate, i.e. only a substitute for soil, which is often sold in compositions that are not very suitable for plants
- After a while, this tends to turn into a rock-hard block that no plant feels comfortable in.
- Maybe a great olive tree fertilizer was also bought, nicely packaged and nicely expensive, but also beautifully mixed wrong
- Your olive tree, like all plants, needs nitrogen, phosphate and potassium,
- This is written as N, P, K on the fertilizer, with numbers in front that describe the mixing ratio
- Olives will do well with any green plant fertilizer containing normal combinations of nutrients
- E.g. 2 parts N, 1 part P, 2 parts K, more P for flowers, a little more K for resistance/frost hardiness
- Even if you cannot find this information on a fertilizer, it is “wrong” simply because the necessary information is missing
- But it is particularly important for the olive tree that it does not get too much fertilizer, it is used to quite barren soil
- Then falling leaves can be caused by all sorts of pests crawling around on the olive…
remedy
If it is not due to wrong overwintering that your olive tree loses leaves, then first of all you need thorough information about the care of olive trees. Then the cause must be determined piece by piece in the process of elimination.
Bad cards from the start?
However, even that will not help if you have treated yourself to a bargain from the discount store, which unfortunately is an olive tree that has undergone a treatment that severely limits its further survival (it is not supposed to continue live, otherwise you won’t buy the next bargain). There are big trees with tiny roots sawn out of rocks, of course you don’t know where such a tree grew either. Or there are young trees with no proof of origin and no information on the variety, grown somewhere in the south, which will die here very soon.
You can try everything described here with such a tree, olive trees have a really tenacious will to survive, but at some point you may just have to say goodbye to them. When buying the next tree, remember that bargains are naturally rather rare, because people have to live from their work, and buy your olive tree from a specialist dealer who knows olives and will answer all your questions about origin, variety and cultivation can answer. That may be a few bucks more expensive (usually not much, people who are passionate about their job usually have other goals than the unrestrained money-making, that the goal is the “I-deal-with-everything-dealer”), but you have a contact person if your olive tree isn’t doing so well.
Simple natural phenomenon?
Maybe nature just takes its course: If only a few leaves fall off the olive tree now and then, that’s completely normal. After all, leaves are formed by the organism like skin flakes, depending on the species and individual, they have a different lifespan – whereby the individual leaf does not grow as old as the plant, just as grandma still has the same skin as in her youth.
care mistakes
Even if it is certainly not intentional, there are typical atrocities that particularly caring hobby gardeners like to do to their plants from time to time. These can sometimes lead to a plant losing its leaves very suddenly, in contrast to the normal leaf aging just described:
- Confused with an aquatic plant and watered much too often
- After a while, the roots begin to rot, then the leaves fall too
- The same happens if the roots are permanently wet because there is no drain on the pot or it is not working
- The olive tree is placed outside, but too early in the cold or too late in the bright sun
- Then the move gives him quite a shock, the olive tree loses leaves
- The olive tree is the last to be watered, with freezing cold tap water, another shock
- In winter, the olive tree stands in the stairwell, in a spot where there is a draft when the door opens
- Excessive growth in length caused by lack of light is never trimmed
- Then the tree loses control of its water balance and slowly starves to death
- The roots have no more space in the pot and can hardly absorb any more nutrients
Again and again you can read that the olive tree in its winter quarters in enclosed rooms certainly gets enough light because it is in a bright room/a south-facing window… No! Illuminance on a bright, sunny day in summer: 100,000 lux, on a winter’s day in the living room: 1,000 lux when things are going really well, dark tomb from the point of view of the plants!
First aid
Correct the wrong location, care mistakes, etc. and leave the olive tree in the right location, “drained” etc. for a while. Now decide: Either simply wait until next spring to see whether it will sprout green again as normal, or – if it seems rather lifeless or if it shows a lot of horny shoots – cut it radically right away, to a few hand-length branches, possibly with a dried-up root ball in the root ball Soak in an immersion bath and otherwise leave it alone until the start of the next growth phase in spring. Then spray it regularly and carefully with water – to stimulate budding, maybe once with a dash of liquid fertilizer (1 teaspoon, no more) in the water.