Orchids with Yellow Leaves

Yellow Leaves

• Orchids may have yellow leaves for many reasons, including the amount of light or water they receive. These factors are especially important for maintaining the health of an orchid plant. Other factors may include nutrient deficiencies and pest or disease problems. Identifying the cause of the yellowing leaves on an orchid allows a gardener to take action to restore the orchid to health before the problem spreads and ruins the blossom or kills the plant.

Sunlight

• The amount of light an orchid receives is vital to its health. Although each species and cultivar requires a different amount of light, too much or too little light can be equally damaging to the orchid. Too much light scorches the leaves of the orchid, causing them to become burned and yellow. Too little light vitiates the orchid, leaving it weak, stunted and causing the leaves to take on a yellow pallor. Ensure the orchid receives the correct amount of light.

Water and Nutrients

• Fertilize the orchid according to the needs of the cultivar. A lack of fertilizer in potting or garden soil gives the orchid nothing to use for nutrients, leading to weak, yellow leaves and can potentially prevent the orchid from blooming. Too much water suffocates the roots of an orchid, causing leaves to swell and turn yellow or brown. Too little water causes dehydration and yellow leaves. Water orchids weekly to ensure the soil remains moist, or according to the cultivar's needs.

Pests and Disease

• Black rot, mosaic virus and collar rot are all diseases that affect the orchid; symptoms can include yellowing leaves, as well as dieback and spots on the leaves. Treat the plant with a fungicide to combat black and collar rot, and replace the potting soil; make sure the soil drains water easily to prevent fungi from surviving in it. Mosaic virus is fatal to orchids. Pests can include aphids and mites, which can be treated with pesticides.