Q.Eureka lemon tree with yellow leaves
So I brought home a Eureka lemon tree that had *slight* yellowing of the leaves. I planted it and it refuses to grow. Leaves have turned all yellow and are starting to fall off. I’ve done everything I can think of. What now? Things I’ve tried:
Dr Earth Fruit tree fertilizer
Epsom Salt
Spraying the leaves with kelp mixture
Mulching
The leaf spray seemed to help the most, although not 100%. Some parts of the previously yellow leaves are now more green, but not totally healed. I’m currently trying water restricting, in case it is a case of over watering, but the tree (which has small lemons on it and did when I bought it), has not put on any new leaves and hasn’t grown at all. It hasn’t died (yet–and I really don’t want it to!) but it is that sickly pale green/yellow color overall. Please help!!!

Your tree is most likely shocked from the move from pot to ground.
Yellowing leaves are generally a watering issue, either to much or to little.
A newly planted tree will need daily water for the first 2 weeks and with temperatures above 85 degrees you will most likely need 2 waterings a day.
Make sure the tree was properly planted and that the soil is adequate for the tree success.
Add 2 to 3 inches of hardwood mulch around the base of the tree to help it retain moisture.
Here is a link to refresh you on the care and growing requirements.
https://www.gardeningknowhow.com/edible/fruits/lemons/how-to-grow-a-lemon-tree.htm