800px digital thermometer Photography credit: Xell

Effect of Low Temperatures on Orchids

Culture

by Anu Dharmani

Originally published in BellaOnline

Posted by Sys Admin about 2 years ago.

Article Blog   Article Index

Tropical orchids are more susceptible to injury due to cold than the temperate orchids. These injuries caused by exposure to low temperatures, affect all parts as well as at all stages of development of tropical orchids; except dormant and underground pseudobulbs. Extent of injury depends upon the duration of exposure to the chilling temperatures. Short periods of exposure may produce only temporary damage. However, prolonged exposure to cold weather can lead to permanent injury, which can cause death of tissue and in extreme cases, the orchid.

Symptoms of cold damage are not unique, but common with other diseases and stresses. These symptoms are not immediately visible but become evident only after internal tissues and functions get affected. Sometimes the symptoms appear much later, once the plant is shifted to warmer temperature and higher light intensity. 

Some of the symptoms are: 
• Orchids exposed to extreme cold show stunted growth and decreased vigour
• Appearance of surface lesions on affected parts 
• Plant tissue appearing water soaked, even if sparingly watered.
• Discoloured leaves; turning brown or yellow
• Plants show a decreased resistance to disease and pests

Prevention and Cure: 
• Use of protective structures is advised such as jute cloth/sacks, burlap sacks, plastic sheets; taking care that the plant is able to breathe. You can also cover the roots with extra growth medium to prevent freezing of roots.
• Orchids, especially the tropical ones, should be acclimatized to decreasing temperatures to increase their resistance to cold.
• Avoid over watering and keep an eye on weather forecast. Remember to reduce the watering frequency, if a dip in temperature is predicted.
• If an orchid gets exposed to low temperatures and shows signs of cold injury, it should then be kept in high humidity but with a lower sunlight intensity.
• Cold injuries do not spread; more sensitive parts are more easily affected. It is best to remove the damaged part/tissue. 

However, remember prevention is better than cure.

Share on Social Media:  
Log in to Add a Comment
New Topics
  1. Milena Radeva asked question Orchid name in category Phalaenopsis
  2. Gilda Gómez asked question Dendrobium loddigesii in category General Discussion
  3. Edward Zapata asked question Selfing Question on Pollinating. in category General Discussion
  4. Edward Zapata asked question Name of Cymbidium? in category General Discussion
  5. Paph hsinying jewel x paph hsying jewel september 09 2018 Adrienne Alexander asked question Can Zygopetalum (genus) be added to the look-up? in category General Discussion
New Comments
  1. giuseppe di ciommo commented on scheduled event "Southern Ontario Orchid Society Orchid Show & Sale" by Southern Ontario Orchid Society
  2. Gilda Gómez commented on topic "Dendrobium loddigesii" by Gilda Gómez
  3. Gilda Gómez commented on topic "How to add a not-listed plant" by Adrienne Alexander
  4. John Vernam commented on orchid Den. Little Andree
  5. Image Carol Holdren commented on member plant Rlc. Prada Green Deluxe by Mary Lane
  6. Edward Zapata commented on topic "Selfing Question on Pollinating. " by Edward Zapata
  7. Edward Zapata commented on orchid Wils. Tropic Breeze
  8. Edward Zapata commented on topic "Some advice please" by Pieter Opperman
  9. Image Carol Holdren commented on member plant Lyon. Over Easy 'sun kissed' by frank Methmann
  10. nguyen doan commented on member plant Aergs. articulata by Tom Kuligowski