What precautions should be taken for foliar feeding of orchids?

In the previous article, I told you about all the advantages of foliar feeding for orchids. So what precautions should be taken for foliar feeding of orchids?

First, non-water-soluble fertilizers cannot be used for foliar feeding of orchids. For different fertilizers of the same nutrient element, the speed of foliar absorption differs. For potassium fertilizers, potassium chloride is absorbed fastest by leaves, followed by potassium nitrate, and then potassium dihydrogen phosphate; for nitrogen fertilizers, urea is absorbed fastest by leaves, followed by nitrate nitrogen fertilizers, and then ammonium nitrogen fertilizers. Fertilizers used for foliar spraying can only be water-soluble; non-water-soluble fertilizers cannot be used.

Second, pay attention to solution concentration and reactions. The principle is that, on the premise that the leaves are not harmed by fertilizer, the solution concentration should be appropriately increased, as this can improve penetration efficiency and give better results, but it must be kept appropriate.

Third, pay attention to how long the liquid fertilizer remains on the orchid leaves. Generally, the fertilizer solution is required to keep the orchid leaves moist for 30 minutes to 1 hour, so absorption is fast and the effect is good. If it dries quickly, the effect will be poor. If it is rained on shortly after spraying, the effect is also poor. Therefore, foliar spraying should be done in the evening of a sunny day or in the early morning with dew, and calm weather is better.

Fourth, the position for spraying foliar fertilizer should be chosen reasonably. Stomata are the doorways for gas and water during plant photosynthesis and respiration, so the spraying position on the leaves should be reasonable. For example, about 85% of the stomata on Cymbidium goeringii leaves are on the underside, and only 15% are on the upper side, so when fertilizing, special attention should be paid to spraying the underside of the leaves. Other varieties of Chinese orchids are roughly the same, so the focus should be on spraying the underside of the leaves.

Fifth, pay attention to the cleanliness of the water. The water used to dilute the fertilizer must be clean; turbid water containing impurities cannot be used. If tap water is used, it must be stored for more than one day until the chlorine has dissipated before use.

Sixth, a single fertilizer must not be applied over the long term. Different fertilizers should be sprayed at different growth stages of orchids, and a single fertilizer must not be applied alone over the long term. For example, in spring when orchid new shoots emerge, nitrogen fertilizers should be the main choice, such as urea, Hyponex (No. 5), etc.; from the beginning of July to the end of August, to promote flower bud formation, phosphorus fertilizers should be the main choice, such as Hyponex (No. 3), potassium dihydrogen phosphate, etc.