Q.What fertilizer for non-blooming citrus to encourage blooms?
10+ year old lemon and orange tree, 8 ft tall. Planted outside but protected in winter. Last year – new enriched soil added around trees. Fertilized – rarely. No blooms but new leaves. What fertilizer would encourage blooms?

Certified GKH Gardening Expert
A high-phosphorus fertilizer or bone meal will help to encourage blooming. Here is more information: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/phosphorus-plant-growth.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/bone-meal-fertilizer.htm

This article will help you:
https://www.gardeningknowhow.com/edible/fruits/lemons/learn-about-fertilizer-for-a-lemon-tree.htm