How and when to water Dendrobium
Plant of tropical origin, it lives in a particularly humid climate, which can be recreated by abundantly vaporizing water on the highest part of the plant, trying to avoid the flowers. The frequency will be every other day in the summer months (even daily in case of strong heat), and will be reduced as the outside temperature drops. Radical wetting, on the other hand, must be more reduced and controlled: small amounts of water three times a week in the summer, preferably dispensed early in the morning. These too will be reduced with the arrival of autumn, until they are almost non-existent during the winter. In case the irrigations are insufficient or the climate is too dry, you will notice that the root system has a distinct silvery gray shade. In this case, you can resort to watering by immersion, placing the plant in a container full of water, so that the pot is covered with liquid up to about halfway. Let it rest for half an hour, then place it in an empty container for a few hours, so that the excess liquid can drain and does not create dangerous stagnations.
How to grow Dendrobium orchids
The Dendrobium prefers a medium-high temperature in the vegetative phase (about 24 ° degrees in summer) and low in winter (10 °). Furthermore, while thriving in very bright areas, it fears direct exposure to sunlight, responsible for burning the leaves. Therefore pay particular attention to doors and windows from which direct light enters: it could be excessive for the plant. To determine this, you can carry out this simple test: bring your hand close to the glass, and observe how the shadow is cast in the chosen area. If the contours are sharp, the light is too direct, if the contours of the shadow are blurred, the area is bright but sheltered, and will be perfect for your Dendrobium. The pruning of leaves and flowers is not necessary, as the plant it eliminates the dry parts by itself. A thinning of the roots may be necessary, perhaps during the repotting operations. Handle the plant with great care, check the root system by cutting only the dry and emptied parts. Clean it carefully from the previous soil, and repot it, taking care to avoid watering for a week, to avoid the development of mold.
Fertilization of the Dendobrium orchid
Since the plant prefers a very ventilated and dry soil, usually formed for the most part by gravel or bark, fertilization becomes essential. This type of soil, in fact, does not provide the sufficient quantity of nutrients to the plant, which will struggle in particular to flourish. A monthly fertilization is necessary, preferably adding a specific commercial product to the irrigation water, or a specific and balanced fertilizer orchids, available at florists or garden centers. Consequently to the thinning of irrigation with the lowering of the temperature, fertilization will also be limited. They will resume in spring and, in case you intend to give a greater boost to flowering, a specific preparation must be used, with higher doses of phosphorus and potassium.
In case of Dendrobium disease, the leaves will give the first signs. Curls, spots and altered color are the warning sign of an alteration in the health of the plant. The main parasites that attack orchids are spider mites, aphids and scale insects, which deprive them of their lifeblood. Pesticide treatments are not well tolerated by orchids, for this reason it is advisable to resort to small preventive measures, such as leaf wetness, or the mechanical elimination of unwanted guests, it being understood that in the most serious cases the intervention of an adequate insecticide.Also some cultivation errors can lead to the development of diseases: fungi, bacterial and viral infections will attack the leaves and roots. This happens especially when there are stagnations, and therefore the excess water is not free to flow, or if clean tools have not been used for pruning operations. Such infections, although latent for years, are often incurable when they appear. It is therefore advisable to use only tools cleaned with alcohol for pruning, and to ensure adequate drainage with the use of a layer of expanded clay.