Xylosma Yellow Veins May Be Due To Lack of Nitrogen

Q. My xylosma bush leaves are dark green with yellow veins, the exact opposite of an iron shortage. I planted these from 5-gallon containers this past January. As the leaves get older, they become more yellow. What is the problem and what can I do

Leaf vein yellowing on xylosma

A. You are right, a lack of available iron commonly affects the color of leaves on newest growth. Mild iron chlorosis in plants is identified with yellowing leaves with their veins remaining a darker green. Newest leaves grown from the plant get yellower and yellower as the season progresses and the green color of the veins may disappear altogether.

            Sometimes the chlorosis is so severe the entire leaf, including the veins, become yellow and the edges of the leaves begin to scorch during hot weather. Besides leaf yellowing, shortages of iron appear always on the newest leaves while the older leaves remain darker green.

 Yellow Vein

            Green leaves with yellow veins has been reported in citrus, frequently grapefruit, and called “Yellow Vein”. I have not seen Yellow Vein on xylosma but there’s a first time for everything.

            In the 1950’s Yellow Vein was demonstrated to be from a lack of nitrogen. Applying high nitrogen fertilizers, like ammonium sulfate, corrected the problem in citrus the following year.

            Wood chips applied to the surface of the soil can also cause a shortage of nitrogen to growing plants if they are not fertilized. Other possibilities include chemical damage but probably no other plant nutrient besides nitrogen.

            What to do? Flush the soil around the roots with lots of water and then apply nitrogen fertilizers such as 21-0-0, compost or blood meal. Flushing the soil with water first might remove any chemicals present causing this problem.

            Apply a nitrogen fertilizer after flushing with water or the water could wash most of the nitrogen away. Apply high nitrogen fertilizers to the soil about 12 inches from the trunk and water it in. Follow label directions on the amount to use since it varies with each fertilizer and depending on its nitrogen content.