What to Do About Brown Leaf Tips on Chinese Cymbidium Leaves? A Detailed Guide to Prevention and Treatment

Orchid leaves grow vigorously, green and sturdy, with graceful leaf posture and spirited form, delighting the eye. If the leaf tips are scorched and the leaves withered, covered in spots like patches of psoriasis, even a rare and extraordinary flower will be greatly diminished. To grow good orchid leaves, I made improvements in the following six areas.

1. The potting soil must be breathable, well-draining, and moisture-retentive. It should have good crumb structure, soft and loose, like a sponge, with medium fertility; leaf mold from the mountains or peat soil is best. If you cannot get these in the city, mix your own nutrient soil. The formulas are: (1) 8 parts spent mushroom substrate, half a part of honeycomb coal ash, and half a part of composted bone meal or oil cake; (2) 6 parts composted sawdust, 3 parts honeycomb coal ash, and 1 part total of vegetable garden soil and an appropriate amount of oil cake; (3) 6 parts composted and sterilized rice husks, 3 parts honeycomb coal ash, and 1 part total of medium sand and oil cake. All three must be mixed thoroughly before use. Their common features are good breathability, drainage, moisture retention, and a soft, loose texture, which benefits the growth and development of orchid seedlings.

2. Watering must be reasonable. Tap water or well water (soft water) that has been settled, left to volatilize, or exposed to the sun can be used. When watering, observe three things: First, check whether the surface soil in the pot is dry and white; if dry and white, water; if moist, stop. Second, consider the season; in winter and spring, if the surface soil is dry and white, you may also water the next day to moisten it; in summer and autumn, when temperatures are high and sunlight is strong, once the surface soil is dry, water thoroughly in the morning and supplement by misting the leaf surfaces in the evening. Third, consider pot size and pot material; water small pots, go slowly with large pots; water clay pots, go slowly with porcelain, glazed, and plastic pots.

3. Fertilize reasonably. Orchid seedlings are very sensitive to fertilizer and have poor resistance to fertilizer damage. Fertilizing should be based mainly on farmyard manure, and it is best to keep it dilute. Too much fertilizer or too high a concentration causes reverse osmosis in orchid roots, resulting in water being drawn out and the root system withering and rotting. The day after top-dressing, water again to prevent residual fertilizer residue from collecting around the base. Orchids have symbiotic orchid mycorrhizae that fix nitrogen, so generally there is no need to apply nitrogen fertilizer. There are three "don'ts" for fertilizing orchids: do not fertilize newly planted orchid seedlings within half a month; do not fertilize during the orchid's dormant period; do not apply top-dressing under high temperatures and strong sun. For top-dressing, foliar spraying is good; use 0.1% monopotassium phosphate, or 1 part vinegar plus 500 times clear water, and spray both the front and back of the leaves. Rice vinegar contains acetic acid, lysine, and glutamic acid, which promote orchid seedling growth, enhance photosynthesis, and reduce transpiration loss.

4. Sunlight must be soft. Orchids are semi-shade plants and need diffused light. They like morning light and evening sunlight and fear direct strong sun. From Minor Heat to Start of Autumn, there are often blazing sun and high temperatures above 35-39°C, and even the "autumn tiger" above 40°C. Direct strong sun obstructs the physiological functions of orchid plants, especially with continuous high temperatures, causing the plants to become semi-dormant or dormant, making it difficult to form leaf buds and flower buds. In summer and autumn, when the sun is scorching, be sure to shade orchid seedlings by 80%, or move the pots to a place with diffused light. In winter and spring, they should receive full sun. The suitable temperature for orchid seedlings is 12-18°C; growth is hindered above 35°C, which is the direct cause of physiological disorders such as leaf scorch, brown leaves, and scorched tips in orchid leaves.

5. Ventilation must be good. The place where orchid pots are placed must have air convection, with a gentle breeze making the orchid leaves tremble slightly. When arranging pots for cultivation, do not crowd them; place them in a single row as much as possible, keeping a distance of 5 cm between pots. If you grow many orchids, it is best to place them on shelves or hang them in the air to ensure ventilation from above, below, and on all four sides.

6. Keep orchid leaves clean. Orchid leaves are the main organs for the plant's photosynthesis, respiration, and transpiration. Keeping the leaves clean is an important task in orchid growing.