Frost protection and avocados

Jan 8, 2010

Today Ventura County Cooperative Extension Farm Advisor, Ben Faber shares some of his knowledge of avocados with us.

Avocados in general are very frost sensitive, however backyards tend to be warmer than open fields and homeowners can often grow trees with less concern than growers.  All young trees are more susceptible to freeze damage than a tree that has a full canopy down to the ground.  The canopy traps heat and keeps the tree warmer than the surrounding air.

When trees are young they are small enough that frost cloth can be framed around the young tree.  This usually provides at least 5 degrees of protection.  Just a blanket can be used, as well as long as a structure is built to keep it off the tree.  When trees get older and are too large to cover, homeowners have used a sting of lights in the canopy to generate heat.  Make sure they are lights designed for the outdoors.

There are differences in how much cold a tree will take.  ‘Hass’ and ‘Holiday’ are very sensitive, while ‘Stewart’ and ‘Zutano’ are much more cold tolerant.  Here is a comparative chart of the different varieties

Variety Frost Resistance

Race

Typical varieties

Critical temperature below which fruit and/or trees are subject to damage

Mexican

Duke, Topa topa, Mexicola, Zutano, Bacon

25 Degrees F

Hybrids

Fuerte, Puebla

28 Degrees F


Guatemalan (Tender)

Ryan, Hass, MacArthur, Nabal, Endranol, Rincon

29 Degrees F

Guatemalan (Very Tender)


Anaheim, Dickinson, Carlsbad, Challenge, Hellen

30 Degrees F