Yellowish-Green Leaves on Willows

Question

My leaves on the willows are a yellowish green, not a vibrant green. I have fertilized the lawn and also put down ironite. Please let me know what else to do to get vibrant green leaves.

Answer 1

Most likely, it is a nitrogen deficiency. Use a nitrogen rich fertilizer. These articles will also suggest other possibilities:
https://www.gardeningknowhow.com/plant-problems/environmental/plant-leaves-turn-yellow.htm
https://www.gardeningknowhow.com/plant-problems/environmental/leaf-chlorosis-and-iron.htm