Washington Navel Orange in Vista CA

[Richard]

@cdamarjian
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Thick rinds on Washington Navel tree

Too much Nitrogen in proportion to P and K. For excellent citrus fruit you’d like annual proportions of 3:1:2 by weight – not volume. Fertilizers with N-P-K of 3-1-2, 6-2-4, 9-3-6, etc. meet this criteria. The growpower 5-3-1 – which I have used, is not an ideal balance but still a reasonable offering. One pound of it contains 0.05 lbs N, etc. As for quantity in citrus growing regions of California, a tree your size could utilize up to net 1/2 lb of N per year.