Location
Olive trees are not indoor plants, so they should be kept outside for most of the year. They are shade-loving plants. Place them in a well-lit area, but avoid direct sunlight, especially during summer.
From June to August, you can keep them indoors in a well-lit spot. However, starting in September, they must be taken back outside. Olive trees adapt well to Tbilisi's climate.
Watering
Bonsai requires regular and careful watering.
In nature, the plant’s roots grow deep into the soil. If there is a period of time without rain, the plant can still obtain the necessary water and nutrients through its deeply rooted system.
In container-bound conditions, the bonsai has no way of regulating the direction of its roots’ growth. In a container, the soil is very limited, which makes the bonsai more dependent on watering than a tree growing in nature.
It is also worth noting that during hot summer days, the movement of water and its evaporation through the leaves regulate the plant's temperature, protecting it from overheating. As long as the soil remains moist, the plant can continue to develop normally even in very high temperatures. However, in case of water deficiency, "burn" spots may appear on the leaves and shoots, which ultimately leads to the plant's drying out.
Watering quantity and frequency
The frequency of watering bonsai depends on the environmental conditions, the soil in the container, and the species of the plant itself. Bonsai needs to be watered not according to a strict schedule, but based on necessity. For example, late spring and summer watering once a day may not be sufficient. There is also a misconception that watering when the sun’s direct rays hit the plant is harmful. In summer, watering bonsai during the sunny part of the day is sometimes even necessary. Therefore, avoid creating a rigid schedule, such as: "Bonsai must be watered once a day, in the evening."
Some plant species require the soil to be consistently moist, while others need less moisture. However, the absolute drying of the soil for a day or two, in most cases, leads to the plant drying out. Be sure to check the soil condition every day and water when necessary.
There are several simple signs to detect soil dryness: when the soil starts to dry, its surface changes color; the surface of dry soil is relatively hard; if the bonsai has been in a container for several months, you can also determine the need for watering by lifting it. There is a noticeable difference in weight; dry soil is significantly lighter. The first sign of delayed watering in deciduous trees is the wilting of leaves and newly grown shoots. A special, small watering can is used to water bonsais, which allows the water to flow slowly. When pouring a large amount of water all at once, the surface of the soil gets washed away, creating small depressions in some areas.
Use regular tap water for watering. The negative aspect of this water is its chlorine content and high levels of minerals. After regular watering with such water, the surface roots and edges of the container will be covered with white deposits. You will need to remove these deposits periodically.
Pay attention that after watering, the water should come out from the drainage holes; otherwise, only the surface may get wet, while the soil beneath remains dry. It’s common for bonsai to be potted in such a way that a large amount of water poured during watering overflows from the surface out of the container. In such cases, pour water slowly in small amounts, ensuring it doesn't spill over the surface, and wait until the water soaks into the soil. Add more until you're sure the soil is completely wet. The sign of well-moistened soil is water coming out of the drainage holes.
If the soil in the container completely dries out, you will notice that an open space forms between the container and the soil. If watered in this condition, the large amount of water will flow straight through the empty space and exit from the drainage holes.
In this case, it is better to place the plant in a larger container, fill it with water up to the container's edge, and once the surface of the soil becomes wet, remove it. Excess water will drain through the drainage holes. In spring and summer, the plant requires more water than in late autumn or winter. In winter, it is possible to water the plant only once a month throughout the season (do not water the bonsai during freezing periods).
It is also important to know when to water your bonsai during the day. In late spring and summer, when temperatures are high, it is preferable to water in such a way that the soil in the container remains moist overnight. Water in the evening, after sunset. If you water only in the morning or midday, the soil will dry out quickly, and the plant will be in dry soil throughout the night. In autumn, when the sun is no longer as scorching, you can water the bonsai at any time of day, preferably in the morning.
Regarding overwatering: When the soil is constantly wet around the roots, the amount of oxygen in the soil decreases, which leads to the deterioration of fine roots. Damaged roots begin to rot, and if this process is not stopped, large portions of the root system will decay. As a result, the tree weakens, and if the situation is not corrected, it will die. Therefore, after thoroughly watering your bonsai, allow the soil to dry out slowly before watering again.
Excessive wetting of the soil in the container can be caused by continuous rainfall. However, even a week of persistent rain will not harm the plant. The danger arises when the soil in the container remains saturated with water for an extended period, throughout the entire season.
Bonsai care in winter
In winter, trees enter a state of dormancy, and their active growth temporarily halts until spring. This dormant period is just as vital for a plant's survival as the active growth phase. Therefore, bringing bonsai indoors during winter solely to prevent it from "getting too cold" is harmful to the plant. Of course, bringing it inside for 1-2 days for decoration will not harm it. But if it stays in warmth all winter, it will inevitably dry out.
In moderate climates, where winters are not too harsh, bonsai does not require special winter care. However, in regions where temperatures regularly drop below -5°C in winter, protecting the plant from freezing is essential, especially its roots. Bonsai roots are not deeply buried and can easily freeze. In Tbilisi's climate, the risk of freezing is lower, but if prolonged severe frosts occur, place the plant in a much larger container, buried in sand or sawdust, to protect the roots from frost.
Protection of Bonsai in Summer
At temperatures above 30°C, if no special measures are taken to protect the bonsai, it can be damaged or even dry out. How well the plant withstands extreme heat depends on the species' heat tolerance and the duration of the high temperature during the day.
The impact of heat on deciduous trees is easy to notice. The plant cools down through the evaporation of water from the leaves. During high temperatures, the plant loses water quickly. If the bonsai does not receive enough water, leaf temperature can reach critical levels. Leaf wilting is the first sign of water shortage. In extreme heat, the plant may prematurely enter dormancy, shedding leaves starting with the inner and lower ones. Direct sunlight can heat the soil, potentially damaging roots. Coniferous plants, however, do not show such "signals" and require extra care in summer.
Bonsai can tolerate very high temperatures if normal conditions for its functions are maintained. There are several simple methods to protect the bonsai from extreme heat. Avoid direct midday sunlight or use shading. Do not place the bonsai on surfaces that get very hot from the sun, such as stone, concrete, or metal. Try to increase humidity around the bonsai by spraying it more often or watering the area around it. Ensure that the soil in the container does not dry out completely. Watering at midday is another way to cool the roots.
Fertilizer
For normal growth and development, in addition to carbon (C), hydrogen (H), and oxygen (O) which the plant takes from air and water, it is essential for the plant to take macro and microelements from the soil. Macro-elements include: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg). It also requires various microelements in very small doses: iron (Fe), copper (Cu), zinc (Zn), molybdenum (Mo), boron (B), manganese (Mn), sodium (Na), and other elements. Each of these elements is vital for the plant's existence. This is especially true for macro-elements. An excess or deficiency of each has a noticeable impact on plant growth. For example, nitrogen is required for regulating growth, leaves, and fruiting. A deficiency in nitrogen is quickly noticeable by slowed growth. Excess nitrogen causes the prolonged growth of new shoots. Adding nitrogen-rich fertilizers does not occur in the second half of the growing season. Phosphorus helps plant development, root growth, and increases resistance to drought and frost. Potassium ensures the plant's resilience to stress (extremely high or low temperatures, excessive or insufficient moisture). The optimal amount of potassium enhances the plant’s ability to overwinter and resist fungal and bacterial diseases. Calcium is necessary for the normal exchange of substances in the plant. Due to limited soil in the container, nutrients quickly deplete. Therefore, regular addition of fertilizer containing all these elements is as essential as watering. Without additional nutrition, the plant develops weakly, leaves and needles discolor, and it becomes more susceptible to diseases.
Bonsai can be fed with both organic and mineral fertilizers, but they should not be mixed and added together. There are fertilizers specifically designed for bonsais, which contain all the necessary elements. Such fertilizers can be either liquid or solid, in granular form. Liquid fertilizer dissolves in water in a specific dose, and the resulting solution is used to water the plant. The plant absorbs liquid fertilizer quickly, so it is added to conifers once every 3 weeks. Granular fertilizers have a longer-lasting effect. Such fertilizer is either mixed into the soil or placed on top of the soil in a small container. With each watering, a certain amount dissolves in water and gradually feeds the bonsai. Special bonsai fertilizer can be ordered online.
If you are unable to find such fertilizer, you can use a combined fertilizer available in gardening or flower shops. Usually, such fertilizers contain all the elements necessary for plants. For bonsais, it is preferable to use one that dissolves well in water. This type of fertilizer is more convenient to use. The packaging always lists the composition in percentages (NPK) and how much water it should be dissolved in. When adding fertilizer, be very cautious and determine the correct dose, because an excess amount can cause the plant to dry out. It is recommended that the fertilizer contains NPK-10-10-10 and microelements.
Fertilizer application typically starts in early spring and ends in the fall. During the winter, fertilization is not necessary. Fertilizer should not be added to freshly transplanted plants. It is only permissible to apply fertilizer 4-5 weeks after the start of the growing season, once the bonsai has established its roots.
You can purchase "Kristalono 20-20-20" fertilizer from Mount Chemistry. Dissolve 2 grams in 1.5 liters of water for use.
Spraying water
Water spraying is essential for both deciduous and coniferous plants. Start spraying when warm weather begins in the spring and continue until the leaf-dropping period starts. In summer, spraying daily is recommended, but of course, there is no need to spray on rainy days.
Spray water while watering the Bonsai.
Some water-soluble fertilizers are also intended for foliar spraying. This helps the development of vibrant, healthy leaves, and prevents them from getting sick easily. There are also foliar fertilizers in liquid form, which have a very positive effect when sprayed. If necessary, spray with water-diluted fertilizer or foliar feed once a week, or at the same interval as you apply the fertilizer to the soil.
Disease and pests.
Like all plants, bonsai can get diseases and pests. Therefore, it is better to carry out prophylactic treatments once a month from spring to autumn. Dissolve Ridomil Gold, Strobistar, and Aktellik in water according to the required dosage and spray. Never treat bonsai in a closed space.