Extension Educator Says Fire-Damaged Avocado Trees Need Care

According to reports from KGTV in San Diego, CA, more than 100 acres of avocado orchards have been scorched in the Lilac wildfire. While the damage may be limited to certain areas, Ben Faber, University of California Cooperative Extension educator for Ventura County offers avocado growers some tips for post-fire management.


Q: What type of damage should avocado and citrus growers be looking for?

Faber: As far as I’ve seen, it’s only been avocados affected by the fire and some of the nurseries up against the hills. The winds have stripped the avocado trees of the fruit all over the two counties. It was blowing on and off more than 50 mph for a week and is still blowing.

Q: Obviously wind damage is somewhat unavoidable, but is there much growers can do in the meantime to help the trees recover? Should growers be concerned about tree stress? Would any of these trees possibly drop fruit as a result?

Faber: With all the wind and heat, growers need to repair their irrigation systems and get water on the trees. With uneven tree damage, growers are going to have to be careful about overwatering damaged trees so that they don’t create root rot situations. It’s going to be hard with some trees damaged and some trees healthy both on the same irrigation system.

Q: What type of biocontrols would possibly be affected by the ash? Is there much growers can do to help keep natural predators happy and nearby? Are there alternatives growers should be considering until the natural ecosystem starts to balance back out?

Faber: Most predators are affected by ash because it slows them down. Pests aren’t so mobile. The predators will spend much of their time grooming and won’t have the time to hunt down mealy bugs, scale, mites, and so on. So the balance is thrown off. We need rain to wash the leaves off, and there is no rain forecast until later in January, maybe. So increased pesticide applications may be necessary, but they will be less effective also because of the ash on the leaves, impeding the efficacy of the chemicals. Asian Citrus Psyllid controls are not going to be as effective, either.

Q: Is there any advice you’d give growers in your area that have been impacted by the fires and winds?

Faber: Legally you can’t pick avocados off the ground and put them into the market. Contact the local USDA-Farm Service Agency office for disaster coverage.

Faber also suggests growers concerned about fire damage visit his blog post about fire damage in avocados, a post about fire readiness, a post about grafting post-fire, and another post about management decisions to make with avocados during fire season.

“The important rule to follow after a fire is to do nothing — don’t prune, don’t fertilize, and maybe don’t water. Or rather, water very carefully. Dry winds may have sucked the water out of the ground and may need to be replenished. The fire may have burned the irrigation lines and they need to be replaced,” Faber writes.