Leaves of the zelkova

Question: leaves of the zelkova

good morning known in my Chinese elm that the leaves have a black border! What should I do?? Thanks for your attention Lele

Answer: leaves of the zelkova

Dear Lele,
the Chinese elm, zelkova nire, is a beautiful bonsai, very suitable for beginners, because it produces very small leaves, and is vigorous and resistant. Generally the edge of the leaves that tends to darken is a symptom of problems related to excess watering; it is not always easy to water the bonsai correctly; often we tend to water too little, leaving the little soil present in the pot to remain dry for a long time, and the result is dry or withered leaves; if instead it is watered too often it can happen that the earthen bread around the roots always remains completely soaked with water, leading to the suffocation of the roots, which are no longer able to have gas exchange with the outside, and with consequent development of fungal parasites . To cure the plant already affected by this problem it is advisable first of all to allow the soil to dry out between two waterings (check with your fingers: if you feel the soil is fresh and moist, send watering for at least a day), and practice at least one treatment with a systemic fungicide, or a product that must be vaporized on the foliage from which it will be absorbed, to enter into circulation in the plant. Often, in addition to the problem of excess watering, this type of pathology develops in plants grown in poorly ventilated areas, with little air exchange, and poorly lit. Bonsai, in the hottest summer months, tend not to love direct sunlight, especially during the hottest hours of the day, but it is always advisable to place them in bright, well-ventilated areas; in the case of your zelkova, it would not hurt to receive a little direct sunlight, possibly in the early hours of the morning. These plants fear intense frost, but if you live in an area where the winters have a fairly mild climate, you can think about growing it on the terrace throughout the year, so that it enjoys a more natural climate; if exposed to bad weather then, in autumn and spring, it will receive the correct amount of watering directly from the rains, allowing you not to think nagging at watering. In any case, whether outdoors or at home, when autumn arrives, it is advisable to further reduce the watering, wetting the soil only when it is completely dry. The zelkoves love a cool and humid climate, but they are afraid of water stagnation, this is why watering is to be provided whenever the soil is very dry, but the foliage often vaporizes, especially in the warm months, or in the case of plants grown in the apartment. Fertilizers (specific for bonsai) are supplied from March to September, every 12-15 days.