With subtly shimmering, lush green leaves, robust cut tolerance and uncomplicated care requirements, the fig tree has established itself as a prime example of the beginner’s bonsai. Popular species, such as the weeping fig or the laurel fig, however, tend to respond to minor and major neglects in cultivation with yellow-discolored leaves. Instead of nipping a hopeful career as a bonsai master in the bud as a result of the damage caused by premature resignation, a targeted program to remedy the shortcoming should be initiated. Read here what yellow leaves on Ficus Bonsai are due to and what to do.
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Main cause of yellow leaves: Wet substrate
The skills in bonsai care include not only correct cutting and skilful wires. The balanced supply of water is just as important for a vital and healthy tree in miniature form. If there is a misalignment here, the ficus reacts with yellow leaves. If the tree is permanently too wet, the fine hair roots die. Paradoxically, despite watering too abundantly, there is a lack of water because the moisture is no longer transported into the foliage. Ultimately, the leaves turn yellow, later brown, and fall off.
What to do? – Repot and pour evenly.
You can pour out the excess water from the bowl and not water the ficus for a while. However, this approach is only advisable if waterlogging has only recently occurred. Yellow leaves on the Ficus Bonsai indicate a longer period of waterlogging, so that more consistent action is required. Therefore repot the suffering tree as soon as possible. This is how you do it:
- Loosen the ball of earth from the edge of the bowl with a sickle knife
- Lift the bonsai out of the bowl with a gentle pull
- Loosen the wet root ball with a root hook and shake off the earth
- Cut off the dead hair roots with disinfected scissors
If the length of the bonsai pot is at least 75 percent of the height, it can still be used. Ideally, you should clean the vessel and spread a special plastic grille over the water drain as a drainage. On top of this, fill in a first layer of the bonsai substrate in order to plant the ficus with roots arranged in a star shape. Press the fresh soil firmly all around with a wooden stick. The previous planting depth should be retained as far as possible. So that the tree can recover from the stress, no fertilization, wiring or cutting is carried out in the following 4 weeks.
From now on you should only water the Ficus Bonsai when the substrate is dry. Use a fine-sprinkled watering can or a ball shower from a specialist retailer and soft, room-warm water.
A typical symptom of a lack of nutrients in a fig tree are yellow leaves with green veins running through them. In the tightly limited substrate volume of a bonsai pot, the nutrients it contains are quickly used up. As a deciduous tree, the weeping fig and its conspecifics require a nitrogen-containing fertilizer, especially at the time of the new budding in spring. If yellow leaves develop even though you are already fertilizing regularly, lime in the substrate blocks the absorption of the nutrients.
What to do? – Fertilize regularly or repot every year and water without lime.If
you have not yet fertilized your Ficus Bonsai, the yellow leaves quickly turn a deep green color again if you apply a liquid fertilizer for green plants every 14 days from May to September. The dosage is based on the manufacturer’s instructions and should be slightly below if in doubt. Alternatively, you can repot the fig in fresh, pre-fertilized substrate every spring.
If the application of fertilizer was already on the maintenance program, check the pH value of the soil. The Chinese fig and other ficus species favor a slightly acidic to neutral soil acidity value of 5 to 6. If the value is 7 and above, the lime content is too high. Important nutrients, such as iron, no longer get into the leaves, which then discolor. If you switch the water supply to soft rainwater, the soil value comes back into balance.
Abrupt change of location to an unsuitable location
Fig trees love constancy in every way. This applies to the large specimens as well as to bonsai. Once the plant has acclimatized itself to the sunny, warm location, it reacts extremely annoyed to a change. If the conditions in the new place are dark and cool, the leaves turn yellow and are thrown off sooner or later.
What to do? – Change of location only under constant conditions
If the move to a new location is unavoidable, the light and temperature conditions there should also be sunny and warm. Ideally, the mercury column fluctuates between 18 and 22 degrees Celsius. If a Ficus Bonsai is exposed to cold drafts, the decorative foliage suffers. The same applies if the bonsai bowl is on the wintry windowsill on a cold bridge from the outside into the inside of the house. You can prevent this by placing the tree on an insulating surface such as styrofoam or wood during the winter after spending the summer outdoors.
All fig species that are suitable for bonsai want to spend the summer in the fresh air and enjoy the warm rays of the sun. In the first time after clearing, yellow leaves appear on the ficus in spring. At this point, you can almost certainly assume it is sunburn.
What to do? – Place more shady for some time
If sunburn is responsible for yellow leaves on a fig, only shading remains for 10 to 14 days. The tree recovers from sunburn in the partially shaded, warm and protected location. In the next year, you can prevent the shortcoming by initially setting up the bonsai for 1 week in partial shade on the balcony to harden it.
Lack of light during the winter
At home in the sunny, warm regions of the world, a fig tree is used to at least 12 hours of daylight. If the days get shorter in autumn, an evergreen bonsai reacts with yellow leaves that fall off after a while.
What to do? – Additional lighting
It is a completely natural process when the leaves on the fig tree turn yellow and fall off in darker light. At the beginning of the next growing season, the tree sprouts again. If, on the other hand, you don’t want to miss the elegant shimmering leaves in winter, provide additional light sources. A seat at the south window is not enough. In addition, the specialist trade offers special plant lamps that are installed above the Ficus. The higher the temperatures during winter, the more light is required so that the leaves do not turn yellow.
Dry heating air
In the tropical and subtropical regions, the humidity is naturally permanently at a high level of 80 percent and more. Although a number of fig species have adapted to the Central European climatic conditions, the dry heating air causes them problems in winter. As a first reaction, the pretty leaves turn yellowish-green.
What to do? – Spray and place a humidifier
If your Ficus Bonsai signals with yellow leaves in winter that it does not like the dry room air, you can remedy this with simple means. Daily spraying of the crown with soft, lukewarm water brings the tree to life. Fill the coaster with pebbles and water, create a tropical-humid microclimate around the mini-tree. Commercially available humidifiers, an indoor fountain or an aquarium increase the humidity in the entire room to a level that is also beneficial for the gardener’s health.
If a ficus bonsai is attacked by sucking pests, its defense strategy is to shed the leaves. Before that, however, the wood still draws in the remaining nutrients, so that the foliage turns yellow.
What to do? – Identifying and combating pests
Careful bonsai gardeners combine every care measure with a meticulous control of the fig tree for pests. In particular, the somewhat brittle bark is used by crafty scale insects as a hiding place. Aphids feel at home on the smooth foliage. As soon as you spot the tiny pests, control measures should be taken to help the bonsai defend itself. For example, you can effectively use the classic soft soap solution against aphids. To do this, mix 1 liter of soft water with 1 tablespoon of liquid core or soft soap and add 1 drop of alcohol. Dab scale insects with a cotton swab soaked in strong alcohol.
Yellow leaves on Ficus Bonsai are no reason to lose heart at once. Embark on a detailed search for the causes. If the problem comes to light, the solution is usually very straightforward. Location problems and an incorrectly balanced water and nutrient balance are often responsible for yellow leaf discoloration. Sunburn in summer and poor lighting conditions in winter are also common triggers, as is dry heating air. If there are pests behind it, there are excellent prospects of saving the bonsai in the early infestation stage, so that it presents itself again with its shiny green leaves.