Most mature avocado trees require regular fertilization with nitrogen. Typically, most other nutrients
are available in sufficient amounts in the soil. Nitrogen should be applied in fall or winter.
Dwarf plants or trees in containers with restricted root space may require less fertilizer.
Avocados occasionally suffer from deficiencies of micronutrients such as zinc or iron. These deficiencies
can be corrected by a foliar application of a liquid chelated micronutrient solution as the new
growth emerges in the spring. You can also apply micronutrients in the sulfated form, such
as zinc sulfate
or iron sulfate, to the soil.
Suggested application rates of nitrogen
- 1st year--1 tbsp nitrogen fertilizer 3 times
a year per tree
- 2nd year--0.25 lb actual nitrogen per tree
- 3rd year--0.5 lb actual nitrogen per tree
- 4th year--0.75 lb actual nitrogen per tree
- 5th year on--1 lb actual nitrogen each year
1 pound of actual nitrogen equals about 5 lb of ammonium sulfate per year or 100 lb of composted
cow manure each year. Organic fertilizers such as manure, bloodmeal, etc. can be
applied in the fall under the canopy.