The leaves of your beloved mini tree suddenly fall off? We explain what can cause this and give tips to counteract it.
You have just proudly carried it home, transplanted it or placed it in its new, much nicer place in the sunny living room - but suddenly the bonsai is completely naked and bare. Despite the horror, it is now time to investigate: why does the bonsai just lose its leaves? The following list shows you numerous reasons that can drive bonsai to drop leaves. If you have an acute emergency to take care of, take a look below to see whether you can still save a bonsai without leaves.
Bonsai Loses Leaves: Possible Causes and Reasons
When a bonsai tree loses all its leaves, the reason is usually a mistake in care. A lack or excess of water, a lack of light, a mistake in fertilizing or the wrong temperature can all cause a bonsai in the house or in the garden to drop all its leaves. But even a sudden change of location or pests can cause sensitive bonsai trees to drop their shells.
Tip: Excess water, lack of water, over-fertilization and lack of nutrients. These problems can lead to leaf shedding and they all affect the bonsai's substrate. They can occur particularly quickly if unsuitable soil is used for the bonsai. Therefore, choosing a suitable bonsai soil is an important first step to keep a bonsai he althy.
Excess water
Too much water is not good for the bonsai at all. If a bonsai is always wet, no oxygen can reach the roots and the entire substrate. The consequences are fermentation processes and the promotion of putrefaction. A substrate that is too absorbent can also be a problem. If the tree grows in material that is too absorbent, it never dries properly and encourages harmful fungi and bacteria. Both will slowly weaken the plant, allowing it to gradually shed all of its foliage.
The solution: Make sure you use a suitable, permeable bonsai substrate for yourBonsai and repot newly purchased bonsai soon after you receive it - the container fillings from the sale are often a bit older or even specially adapted to the long transport and unsuitable for permanent cultivation. Always check the moisture of the substrate with your finger first and only water when it is dry.
Water shortage
A lack of water can also cause bonsai to drop leaves. Because the pots of bonsai are relatively small in order to slow down the growth of the plant, the water-storing volume is also very limited. If watering is then neglected, there will soon be no more water available - the result can be leaf shedding and the death of the bonsai very quickly.
The solution: A lack of water can also be triggered by the "transport substrates" mentioned above, because these sometimes become hard as stone after drying and can hardly be moistened again. So again the tip: Always repot newly bought bonsai as soon as possible. Otherwise, it is simply a matter of watering regularly and using a high-quality bonsai substrate that stores enough water well. If watering is difficult due to the tiny surface area, a weekly soak of the entire pot may be a more practical alternative.
Lack of Light
The small bonsai have a great need for sunlight. Indoor bonsai in particular often suffer from simply being too dark. This leads to poor growth or, in the worst case, to shedding the foliage.
The solution: The right place for a bonsai is the light-flooded window on the south side. It is even better to place indoor bonsai outdoors in the summer, where they can absorb a lot of energy in the form of sunlight. Just like for outdoor bonsai that grow outdoors all year round, the perfect place for the bonsai in the garden is not in the blazing midday, but rather in the sloping morning or afternoon sun. However, a slow acclimatization to the new circumstances is advisable in order to avoid sunburn and sudden water shortages due to increased evaporation.
Tip: Ficus bonsai like the Ficus Ginseng ( Ficus microcarpa) and also several Ulmus bonsais have a special characteristic: They quickly adjust the amount of their leaves to the respective light conditions. Because of this, it can happen that when the light conditions change, they suddenly lose a part of theirDiscarding leaves and only keeping the amount you really need - that's not necessarily a cause for concern.
Cold or heat stress
Not every bonsai is the same and every species has been adapted to specific conditions in its evolutionary history. If your bonsai is too cold or too warm, this can exceed its physiological possibilities, which can result in stunted growth, shedding of leaves and eventually in the death of the sapling.
The solution: If cold or heat stress are the causes of leaf shedding, the solution is very simple: Adapt the growth conditions of your protégé to their needs. It is even easier to explore the options available to you from the outset and then select the right bonsai.
Overfertilization or lack of nutrients
A nutrient deficiency or excess can also lead to leaf fall. While nutrient deficiency is gradually becoming apparent through typical signs - the bonsai develops yellow leaves, hardly grows or shows typically arranged leaf discolouration - a nutrient excess is somewhat more difficult to recognize. In general, the plant then suddenly makes a limp impression, so the foliage is without cell pressure, soon discolors and is quickly shed - with heavy over-fertilization, the death of the plant is as good as sealed. In contrast, the plant can endure a lack of nutrients for a long period of time before shedding its leaves as a result.
The solution: A lot is gained when using fertilizers if you follow the manufacturer's specifications. If you don't want to use a special bonsai fertilizer, you can find out the right dosage by trying it out or by asking the manufacturer. In general, it is advisable to start with a little less fertilizer and to approach the optimal amount by observing the resulting growth behavior. After acute over-fertilization, the root ball should be rinsed under plenty of running water as soon as possible - this will wash out excess nutrients and limit damage. If you want to prevent over-fertilization, we recommend primarily organic fertilizers such as our Plantura organic fertilizers, because over-fertilization is not possible with them.
Tip: Good bonsai soil contains onesignificant proportion of fine clay minerals. These can absorb nutrients from the soil and store them, but also release them again when needed. In this way, surpluses are buffered and deficiencies compensated.
Change of location
"If a bonsai is suddenly moved and finds completely different conditions - drier air, less light, heat or cold - it takes a lot of strength to adapt to them again. Specialized cells are now formed in the plant or adapted transport routes for hormones or nutrients are modified - a huge, exhausting effort begins. No wonder, then, that sensitive bonsai species tend to shed all their foliage. However, it usually grows back quickly if you take good care of it. It is therefore also not unusual for a bonsai to lose all its leaves after repotting. The associated shortening of the roots is a huge challenge for the small trees.
The solution: Unfortunately, a drop of leaves as a result of a change of location cannot be prevented. Under no circumstances should you relocate the plant immediately because of the shock - it takes a little time and, with good care, will soon sprout again with new leaves. Keep in mind, however, that good care doesn't necessarily mean particularly frequent watering and fertilizing - the plant has little need for it without foliage.
Tip: The beautiful June snow (Tree of a Thousand Stars, Serissa japonica) is particularly notorious for its sudden fall of leaves is notorious as a very demanding bonsai species. In fact, the June snow is fairly easy to care for, it owes its bad reputation to the sudden fall of leaves after a change of location - for example from the shop to your living room.
Pests and Diseases
Pests or diseases are very rarely the cause of a bonsai losing its foliage. Both often only come into play when the bonsai has already been weakened by inanimate (abiotic) factors such as those mentioned above. And it is not uncommon for an unnecessary treatment with pesticides to provoke the leaf fall of the sometimes sensitive plants.
The solution: Bonsais are grown from a variety of very different tree species. And just as unmanageable is the abundance of pests and diseases that can lead to leaf fall in the various bonsai. If you have found a pest or disease, you should proceed as you would with any other plant: with determining the cause andsubsequent targeted combat.
Tip: Pests can also live in the soil in the bonsai pot. Fungus gnats, for example, are a common problem indoors. Their larvae are often introduced via inferior potting soil. Therefore, the same applies here: Choosing a high-quality bonsai soil can save you trouble later.
Bonsai loses all leaves in winter
Every year does your bonsai lose all its leaves in winter? Falling leaves are not necessarily the sign of a problem. All temperate broadleaf species and even some conifers such as larch (Larix) and sequoia (Metasequoia) also shed their needles in autumn.
The solution: Find out exactly what kind of bonsai your specimen is and check whether the leaf fall is not normal.
Can you save a bonsai without leaves?
If a bonsai has dropped its foliage due to seriously unfavorable living conditions, this is a sign that it is already in a very bad way. But if the plant is still alive, there is still some hope. If you're not sure, you can quickly find out: scrape the bark flat with a sharp object or your fingernail to remove the top layers. If the green cambium can be seen underneath, this shoot is still vital. It is quite possible that finer branches have already died, but the trunk is still alive and could sprout again. Therefore, if necessary, check different places on the bonsai.
What can you do now to best help your bonsai survive? Repotting or cutting are initially taboo. Try to optimize the sapling's living conditions, and most importantly, fix the problem that caused it to shed its leaves. Depending on how many reserve substances the plant has stored in the roots and trunk, it will be able to muster the strength to sprout. If the bonsai was doing badly for years before the leaves were dropped, its chances for a new start are not particularly good because there are hardly any reserves available. In general, a bonsai should have sprout again by next spring at the latest - otherwise its death is unfortunately sealed.
If you would like to read more about the correct care of bonsai, you will find our special article on watering hereof bonsai trees.
Many thanks to Floragard for the support!
