You can tell which fertilizer an orchid lacks just by looking at leaf symptoms
Collected in the wild in Zhejiang, has won awards at multiple orchid shows. A new cultivar of Cymbidium goeringii 'Three-Star Butterfly'.
Whatever nutrient an orchid lacks will show up on its leaves or on the plant itself; by observing this, you can apply the right fertilizer for the symptoms, so fertilizing is no longer blind.
(1) New leaves are shorter and narrower than old leaves and thin in texture, leaf color is pale yellow, lacking luster: nitrogen deficiency.
(2) Leaf buds elongate slowly and are slow to send out roots, leaf margins curl slightly upward: phosphorus deficiency.
(3) Leaf margins and leaf tips turn yellow (old leaves first, then new leaves), then turn brown; the main and lateral veins of the leaves are rather thin; leaf texture is soft and tends to bend and droop; if exposed to strong light and low temperatures, new leaves show slight dehydration: potassium deficiency.
(4) Old leaves turn yellow; the leaf tips and leaf margins of middle-aged leaves turn yellow and curl toward the leaf surface (commonly called "copper gong rim"): magnesium deficiency.
(5) Leaves shrivel, lose green color, and have little luster; even with proper shading, sunscald-like spots appear, and within the spots there are more spots; flower buds do not develop: manganese deficiency.
(6) Leaf tips are hook-shaped (except where this is a cultivar characteristic), commonly seen in plants grown in acidic soil and given acidic fertilizers: calcium deficiency.
(7) The mesophyll of young leaves turns yellow to white, and the midrib, leaf margins and leaf tips show scorched brown necrotic spots: iron deficiency.
(8) The middle section of the lower leaves shows pure rust-like spots, which gradually spread toward both ends of the leaf; the petiole ring of new growths is noticeably lower than that of old leaves: zinc deficiency.
(9) Leaf tips lose green color and gradually turn grayish-white, spreading to the whole leaf, and growth stalls: copper deficiency.
(10) The base of young leaves is damaged, the petiole ring is extremely brittle and breaks easily, the number of flowers is noticeably reduced, flower buds open slowly and bloom listlessly, and after blooming the flowers' lasting period is noticeably shortened: boron deficiency.
(11) Without applying chlormequat, new growths are still noticeably dwarfed; old leaves lose green color, then turn withered yellow, wilt and become necrotic: molybdenum deficiency.