Post-freeze Avocado Grove Management
Freezing temperatures can cause fruit loss and even tree damage in California’s avocado growing regions. In the event of a freeze or snowfall, here are some key points to remember as you assess the damage in your grove.
After a freeze, California avocado growers should look for the following indicators of freeze damage:
- Firm, brittle, curled leaves
- Water‐soaked or discolored wood or twigs
- Older branches and trunks splitting and losing bark
- Discolored avocados, with hues ranging from barely visible bronze to black
Post freeze avocado tree care:
- Soon after frozen leaves fall, whitewash defoliated trees with white-latex or lime-based paint to protect damaged wood from sunburn, which can cause further damage.
- Do not apply dressings — or additional paint‐on sealants — to cracked bark, as it might strengthen bacterial or fungal infections.
- Broken limbs or other physical damage from snow and ice should be pruned as soon as possible to prevent further damage and promote healing.
- Pruning of frozen branches can be postponed until spring or summer, when new growth develops and the full extent of damage can be determined.
- Because freeze-damaged trees require less water, irrigation should be done judiciously and reduced in proportion to lost canopy, according to their evapotranspiration requirements (be cautious at this stage, as waterlogged root zones can further stress trees).
- Survey damaged trees before applying fertilizer, to identify what minerals are lacking, as nitrogen applications are likely to trend downward. It is suggested that avocado growers withhold nitrogen fertilization until midsummer (or longer). However, zinc sprays often are applied to expanding young foliage.
Post freeze avocado harvest
- Because stem-damaged fruit will drop within seven to ten days of a freeze, it should be picked first, assuming it is mature and not otherwise harmed by the cold.
- While stem damage may be apparent, fruit might be unscathed. When stems are completely girdled by a brown band, fruit will drop. Drops typically occur within seven to 10 days following a freeze.
- Do not pick any discolored avocados (barely visible bronze to black).