Orchids With Frost Damage

Temperature

• Orchids with frost damage most likely suffered the injury if temperatures have fallen below 50 degrees Fahrenheit. Most orchid species grow best when nighttime temperatures hover between 60 and 70 F. When frost fills the air, the majority of orchids recover from damage if the temperature remains in the mid-30s for only a short time. As long as no frost forms on the leaves, the orchid generally escapes serious injury.

Environment

• Frost damage occurs when dew freezes on orchid leaves' surfaced as the result of air temperature dropping below freezing. Symptoms of frost injury typically begin several days after the frost event occurred with their intensity dependent on the extent of the frost and the growing environment immediately after the damage. Signs of injury begin showing more quickly if the environment reverts immediately to warm and sunny conditions.

Treating Damage

• If orchids with frost damage are subjected to the warm, humid and sunshine-laden weather after a frost, they quickly lose water and suffer stress, resulting in a browning and wilting of the leaves. However, immediate watering is not advisable. Allow the soil to dry and place the plant in a humid environment, but one free of direct sunlight and high temperatures. Only water the plant when new growth appears.

Damage Prevention

• The best way to protect against orchid frost damage is to thoroughly understand the temperature preferences of each particular species. Orchids that are most vulnerable and container-grown should be moved indoors when cold weather threatens. Do not water orchids planted in the earth outdoors the day before a cold event threatens. This minimizes the amount of water in plant tissue that can freeze, thus reducing cold injury to the orchid.