Question:  I just moved into a house that has been empty for several months.  There are neglected citrus and avocado trees in the yard.  How should I care for them?
Susan Finn SLO
 
Maggie King  Master Gardener

Is it any wonder that we love living on the Central Coast?  In most areas of the county, citrus trees and avocados can be grown with relative ease.  They are beautiful year round.  They produce bountiful quantities of delicious fruit.  Few scents are more intoxicating than citrus blossoms.  Surely, one of our most important gardening tasks should be proper care and feeding of these wonderful gifts from nature.  

Lack of proper nutrients can affect fruit size, flavor, color and abundance. Commercial citrus growers use sophisticated techniques to analyze the nutritional needs of their trees.  For the home gardener these tools are not practical, but there is some basic information that will help us care for our orchards.

The primary nutrient that citrus trees need regularly is nitrogen.  For young, non-fruit-bearing trees, frequent, small applications of nitrogen are recommended.  Once maturity is reached, a citrus tree in the home garden should be fertilized at a rate of about one pound of actual nitrogen per tree per year.

Nitrogren deficient

Iron Deficiency

Both phosphorous and potassium should be supplemented occasionally.  Deficiencies in iron, zinc and other minerals are relatively uncommon in California orchards, but when present can usually be treated with foliar sprays.  Deficiencies of minerals show up in characteristic changes in the leaves.

Calculating the amount of ACTUAL nitrogen and other nutrients in any given product can be challenging.  With the variation in citrus types, fertilizer formulations, soil types and specific planting locations, a single recommendation for when to fertilize is not possible, but most experts suggest a good dose of nitrogen in late winter or early spring.  As always, the Master Gardeners are happy to answer your questions. The following websites may be helpful as well.