Oh my, those trees are struggling. I'm so sorry! It's always disheartening when we work so hard to care for our little trees and things don't go as planned.
It looks like there are several problems going on.
First off, the trees look sun burned. Citrus do need plenty of sun; but they can benefit from a bit of afternoon shade in the harsh desert sun.
Second, the trees look nitrogen deficient. Desert soils are often severely depleted of nitrogen. This could be due to a lack of nitrogen in the soil or a failure of the trees to absorb nitrogen due to root rot, calcerous soil, high pH, or improper watering practices. Unfortunately these trees may have been doomed from the beginning when you mixed in garden potting soil with the native soil. This makes it very difficult to water correctly and creates an unhealthy environment that does not encourage the roots to establish themselves in the native soil.
Personally I would start over. Get a soil test from several spots in your yard and select a location with a ph between 6 and 7. When you plant your new trees do not mix in potting soil or any other soil amendments. Instead plant the tree several inches above the soil line and top dress with a good compost. Plant in the late fall or early spring so the tree has plenty of time to get established before 100 degree + weather. Also monitor soil moisture and only water when the top few inches of soil are dry. Mulching can help preserve moisture. Each watering should put at least 3 inches of water into the basin (15 gallons of water for a 10 sq. ft. basin).
Topic: Grapefruit, Orange Leaf Pics (Read 794 times)