Bonsai care (olive)
Location
The olive is not a houseplant, so it should spend most of the year outdoors. It prefers some shade. Place it somewhere bright, but keep it out of direct sun, especially in summer. From June through August you can keep it indoors, in a well-lit spot. From September, though, be sure to move it back outside. The olive copes well with the Tbilisi climate.
Watering
A bonsai needs regular, careful watering. In nature, a tree’s roots grow deep into the ground. If it happens not to rain for a while, the deep roots still allow the tree to get the water and nutrients it needs. Confined to a container, a bonsai has no way of directing its roots to grow where they need to. There is very little soil in a pot, which is why a bonsai depends on watering far more than a tree growing in nature.
It is also worth noting that on hot summer days, the movement of water through the plant and its evaporation from the leaves regulate the tree’s temperature and protect it from overheating. As long as the soil is moist, a plant can keep developing normally even in very high temperatures. When water runs short, “scorch” spots appear on the leaves and shoots, and in the end this causes the tree to dry out and die.
How much and how often to water
How often a bonsai needs watering depends on the conditions it is kept in, the soil in the pot and the species itself. A bonsai should be watered not on a strict schedule but as it needs it. In late spring and summer, for example, watering once a day may not be enough. There is another misconception: that watering while direct sun is on the plant harms it. In summer it is sometimes even essential to water a bonsai during the sunny part of the day. So don’t set yourself a schedule along the lines of: “The bonsai must be watered once a day, in the evening.”
Some species need soil that stays constantly moist, others need less moisture, but letting the soil dry out completely for a day or two very often kills the tree. Be sure to check the condition of the soil every day and water when it needs it.
There are a few simple signs that the soil is drying out: as the soil starts to dry, its surface changes color; the surface of dry soil is noticeably harder. If your bonsai has been in its pot for a few months, you can also tell whether it needs water simply by picking it up. The difference in weight is quite noticeable — dry soil is much lighter. On deciduous trees, the first sign of late watering is drooping leaves and new shoots. Bonsai are watered with a special small watering can that lets the water flow out slowly. Pouring a lot of water at once washes away the soil surface and leaves hollows here and there.
Use ordinary tap water. Its drawbacks are chlorine and a high salt content. After regular watering with such water, the surface roots and the rim of the pot become covered with a white crust, which you will need to remove from time to time.
Make sure that after watering, water runs out of the drainage holes; otherwise only the surface may get wet while the soil deeper down stays dry. Quite often a bonsai is planted in its pot in such a way that much of the water poured on runs off the surface and over the side. In that case, pour the water slowly, only as much as the surface can hold without overflowing, wait for it to soak in, then add more, until you are sure that all the soil in the pot is wet. The sign of thoroughly wetted soil is water running out of the drainage hole.
Suppose the soil in the pot has dried out completely. If you look closely at the pot in that case, you will see a gap open up between the pot and the soil. If you water it in this state, much of the water will run straight through the gap and out of the drainage hole.
In this situation it is better to stand the pot in a larger vessel, fill it with water up to the rim of the pot, and lift it out once the soil surface is wet. The excess water will drain out through the drainage holes. In spring and summer a tree needs much more water than in late autumn or winter. In winter it may turn out that you water the tree only once a month for the whole season (do not water a bonsai during frosts).
The time of day you water also matters. In late spring and summer, when temperatures are high, try to water so that the soil in the pot stays moist through the night. Water in the evening, after sunset. If you water only in the morning or at midday, the soil will soon dry out and the tree will spend practically the whole night in dry soil. In autumn, when the sun is no longer so scorching, you can water your bonsai at any time of day, preferably in the morning.
Now for overwatering. When the soil around the roots is constantly wet, the amount of oxygen in it drops. This then damages the fine roots. The damaged roots begin to rot, and if the process isn’t stopped, much of the root system will gradually rot away. As a result the tree first weakens and, if the situation isn’t corrected, dies. So once you have watered your bonsai thoroughly, let the soil dry out gradually, and only then water again.
Soil in a pot can also become waterlogged from persistent rain. But even a week of nonstop rain will not harm the tree. The danger is when the soil in the pot stays soaked with water constantly, all season long.
Bonsai care in winter
In winter, trees are dormant and their active growth is suspended until spring. Dormancy is just as essential to a tree’s vitality as the period of active growth. That is why bringing a bonsai into the warmth in winter simply because it “might get cold” is fatal for the tree. Of course, bringing it indoors for a day or two to decorate a room will do no harm. But if it spends the whole winter in the warmth, it will certainly die.
In temperate regions, where winters are not too harsh, a bonsai needs no special conditions to overwinter. But in regions where winter temperatures regularly drop low (-5°C and below), the tree must be protected from frost. This applies above all to the roots. Bonsai roots are not buried deep in the ground, so they can easily freeze. In the Tbilisi climate the risk of freezing is lower. But if hard frosts go on for a long time, take a vessel much larger than the pot and bury the tree, pot and all, in sand or sawdust. That way the roots are relatively well protected from frost.
Protecting bonsai in summer
At temperatures above 30°C, unless special measures are taken to protect a bonsai, the tree can be damaged or even die. How well a tree withstands abnormally high heat depends on its own heat tolerance and on how many hours of the day the high temperature lasts.
On a deciduous tree the effects of heat are easy to spot. A tree cools itself through its leaves, by evaporating water. In high temperatures it loses moisture quickly. When a bonsai doesn’t get enough water in the heat, the leaf temperature can reach a critical point. Wilting leaves are the first symptom of water shortage. In extreme heat a tree may go dormant prematurely (as it does in autumn). The leaves change color and drop, first the inner and lower leaves of the canopy, then the rest. When a bonsai stands in direct sun, the soil in the pot also heats up considerably. High temperatures can damage the roots as well. Under such conditions the tree becomes less resistant to diseases and pests. These processes are hard to notice on a conifer, however, because its needles give no such “signal”. That is exactly why conifers need special attention in summer. A tree can cope quite well with very high temperatures if you give it normal conditions to function. There are a few simple ways to protect a bonsai from extreme heat. Keep it out of direct midday sun, or rig up some shade. Don’t stand a bonsai on a surface that gets very hot in the sun: stone, concrete, metal. Try to raise the humidity around the bonsai: mist it more often and water the area around it. Make sure the soil in the pot never dries out completely. Watering at midday is another way to cool the roots.
Fertilizer
For normal growth and development, besides carbon (C), hydrogen (H) and oxygen (O), which a plant takes from air and water, a plant must obtain macro- and micronutrients from the soil. The macronutrients are nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg). Various micronutrients are also needed in very small amounts: iron (Fe), copper (Cu), zinc (Zn), molybdenum (Mo), boron (B), manganese (Mn), sodium (Na) and others. All of these elements are vital to a plant’s existence, the macronutrients above all. An excess or a shortage of any one of them has a marked effect on a plant’s development. For example: nitrogen is needed to regulate growth, for the leaves and for fruiting. A nitrogen deficiency soon shows itself as slowed growth. An excess makes new shoots keep growing for longer. Nitrogen-rich fertilizer is not applied in the second half of the growing season. Phosphorus promotes the plant’s development and root growth, and strengthens its tolerance of drought and frost. Potassium gives the plant resilience to stress (very high or low temperatures, too much or too little moisture). The right amount of potassium improves the buds’ ability to survive the winter and the tree’s resistance to fungal and bacterial diseases. Calcium is essential for normal metabolism in the plant. Because there is so little soil in a pot, the nutrients are soon used up. That is why regular feeding with a fertilizer that contains all of these elements is just as essential as watering. Without additional feeding a tree develops poorly, its leaves and needles lose color, and it falls prey to disease more easily.
For bonsai you can use either organic or mineral fertilizer, but never mix the two together and apply them that way. There is fertilizer made specifically for bonsai that contains all the necessary elements. It comes either as a liquid or as solid granules. Liquid fertilizer is dissolved in water at a given dose and the tree is watered with the solution in the usual way. A tree absorbs liquid fertilizer quite quickly, so on conifers it is applied once every 3 weeks. Granular fertilizer works over a longer period. It is either mixed into the soil or placed on the soil surface in special small baskets. With each watering a little dissolves into the water and slowly feeds the bonsai. You can order special bonsai fertilizer online. If you can’t find such a fertilizer, you can use a balanced compound fertilizer sold in garden centers or flower shops. As a rule, these contain all the elements plants need. For bonsai it is best to use one that dissolves easily in water, as it is more convenient to use. The packaging always lists the composition in percentages (NPK) and how much water to dissolve it in. Take great care when feeding and measure the dose accurately, because too much can kill the tree. Ideally it should be NPK 10-10-10 and contain micronutrients. Feeding normally begins in early spring and ends in autumn. No fertilizer is needed in winter. Never feed a freshly repotted tree. Fertilizer may be applied only 4–5 weeks after the start of the growing season, once the bonsai has rooted in well At Samto Kimia you can buy “Kristalon 20-20-20” fertilizer. Dissolve 2 grams in 1.5 liters of water.
Misting
Misting is essential for both deciduous trees and conifers. Start misting when warm weather arrives in spring and continue until leaf fall begins. In summer it is best to mist every day; naturally, there is no need to do it in rainy weather. Mist your bonsai when you water it.
Some water-soluble fertilizers are also intended for spraying on the leaves. This encourages lush, healthy foliage, and the leaves don’t fall ill so easily. There are also water-soluble foliar feeds whose spraying gives quite good results. If you need to spray with dissolved fertilizer or foliar feed, do it once a week, or as often as you feed the soil.
Diseases and pests
Like all plants, bonsai suffer from diseases and are attacked by pests. So it is best to spray preventively once a month from spring to autumn. Dissolve Ridomil Gold, Strobi Star and Actellic together in water at the recommended doses and spray. Never spray a bonsai in an enclosed space.
