See what factors lead to citrus freeze damage and what symptoms to look for.

It’s that time of year when severe freezes could affect citrus trees, causing citrus freeze damage. A bad cold snap could happen at any time during the winter months. A recent publication in Citrus Industry Magazine shared the ins and outs of citrus freeze damage written by Extension agents with UF/IFAS. See a summary below.

Factors Responsible for Freeze Damage

A few factors increase the likelihood that citrus freeze damage will occur, and the severity of the damage. According to the publication, factors that contribute to freeze damage include:

  • minimum temperature
  • duration of freezing temperatures
  • stage of tree acclimation

Additional factors that determine a citrus tree’s susceptibility to freeze damage include:

  • tree vigor
  • scion and rootstock
  • crop load
  • grove and soil conditions

Citrus Freeze Damage Symptoms

Citrus freeze damage is caused by the liquid in the plant’s cells freezing and damaging the cell structure during cold weather. Symptoms of freeze damage vary, but could include:

  • Dark, water-soaked areas on the surface of the leaves
  • Areas turning brown
  • Frozen, killed leaves appear bleached or tan to brown in color
  • New succulent growth will often turn blackishwhen frozen

Recommendations for Determining Citrus Freeze Damage

Research into freeze damage has been on-going, and there are many recommendations on detecting and determining freeze damage, though there isn’t much that can be done to reverse freeze damage. Detection tips include:

  • Leaf drop within a few days indicates that the wood is likely not damaged or killed, but leaf retention on the twigs usually indicates wood kill.
  • Scraping the outer layer of bark can reveal green tissue that, in most cases (but not all), indicates live wood, while brown tissue means the wood is freeze-damaged and dead.
  • It is recommended not to initiate pruning operations until the extent of the damage is known.
  • Fruit drop caused by freeze damage may occur quickly or take time.
  • Some fruit shows no external damage, other fruit may have dark or reddish-brown depressions, pockets or pitting on the peel surface.
  • Fruit damage can be extensive internally

Griffin Fertilizer is committed to helping both growers and ranchers make sound agronomic and economic decisions in order to maximize the health of their grove and pasture. As a full-service custom dry & liquid fertilizer blender and crop protection product distributor, we will continue our mission to further advance Florida agriculture. For questions or concerns about your farm or pasture, contact us and one of our team will be in touch.

Photo courtesy of USDA.