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fruit tree fertilization #937145

Asked June 29, 2026, 9:14 AM EDT

HI- We did a soil test with you last fall, but didn't apply the fertilizer this spring. Now we have apples on the tree. Is it too late to apply the fertilizer? Is there anything we should adjust if we do it now?

Ingham County Michigan

Expert Response

Hello Jennifer,

Based on your soil test

Using Phosphorus: Apply 0.5 lb 0-46-0 (Triple Super Phosphate - TSP) per 100 sq ft in the spring

I did the Fertilizer Calculator:
Based on 1 lb. P2O5/1000 ft.²
2.17 lbs of fertilizer to apply 1 lb. P2O5/1000 ft.²

However, fertilizer recommendations are in lbs/100 sq ft; I divided the result you get by 10.

.217 lbs of fertilizer to apply .1 lbs/100 sq ft. 

That is, it is 1/10th pound per 100 sq ft

I say you need to do at least one application of:

Phosphorus: Apply 0.5 lb 0-46-0 (Triple Super Phosphate - TSP) per 100 sq ft.

I am saying this because Phosphorus (P) is Below Optimum

One now and one in September.

I hope this helps!




An Ask Extension Expert Replied June 29, 2026, 4:28 PM EDT

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