Landscaper's Challenge: Diagnosing Citrus Tree Problems

One of the benefits of living in the Sarasota Florida area is being able to grow beautiful and productive citrus trees. Nothing says Florida like being out side in the evening when the fragrance of blooming Orange trees is carried in the air.

However as with many other fruit trees, citrus trees can be prone to problems both from nutritional deficiencies and diseases or fungus. The one major advantage a landscape maintenance company or homeowner has when figuring out what is wrong with an ailing citrus tree is most of the common citrus tree problems have highly visible symptoms. These symptoms can show themselves in a variety of ways including overall yellowing of the leaves, yellow spots or yellowing veins on the leaves, black spots or other problems with the fruit, or even dropping all of the fruit in a short amount of time. In this article we'll show a few examples of some citrus tree problems and how to remedy them.

The problems can be put into 3 general categories, Disorders, Diseases & Pests, and Nutritional deficiencies. Problems with inconsistent irrigation can also lead to issues with citrus plants.

Well start off with a quick note on a subject near and dear to our hearts: irrigation. Citrus trees like to have consistent moisture evenly dispersed. A weekly moderate watering of the tree would be preferred to letting things dry out then a heavy douse of water. Also over watering your citrus trees can cause major problems with root-rot and invite fungus and other pests so when diagnosing citrus tree problems always start with the irrigation and soil conditions. Further on that end, though citrus trees need consistent even soil moisture to stay in top health, they also require well drained soil, that is not in a low or soggy spot. Once we have ruled out watering problems as an issue we can look at the other possible causes.

This article will focus on Nutritional Deficiencies

One of the easiest problems to overcome with citrus trees is fixing a nutritional deficiency. To determine the type of nutritional deficiencies your citrus plant may have well need to take a close look at the leaves. The leaves will yellow in a variety of ways specific for each deficiency but the culprits is usually found in deficiencies of Nitrogen, Magnesium, Iron, Zinc or manganese. If your citrus plan suffers from any of these, your yard maintenance company should be able to fix the problem with the proper fertilizer coupled with a supplement of the deficient mineral.

Nitrogen Deficiency - A common problem with citrus is nitrogen deficiency. This will show it's self with and overall yellowing of the leaves. The color has a slight orange hue as opposed to a bright yellow common with other problems and the yellowing covers the entire leaf, not just spots or the veins. The veins will be nearly the same color as the leaves. The tree will have fewer leaves than normal because a nitrogen deficiency will cause it to drop leaves. The new leaves will be much green than the old leaves. A proper fertilizer program should correct nitrogen problems.

Zinc Deficiency – Zinc deficiency, also known as "little leaf", "mottle leaf" and rosetting will cause major problems with citrus plants especially if it is bearing fruit. A bad case of zinc deficiency will not only affect the color of the leaves but actually change there shape from more rounded to more pointed and much smaller than healthy leaves. Zinc deficiency will drastically reduce the size of fruit growing on the tree. Zinc deficiency cannot be corrected wit traditional fertilizer but can only be corrected by spraying a solution of sulfate, oxide or nitrate. The best time of year to spray the citrus tree would be during the spring flush to ensure that new growth has adequate zinc going forward.

Iron Deficiency – If your citrus plant's new growing leaves are very light colored and the veins of the leaves are actually a darker green than the leave the plant may have an iron deficiency. This problem is common in alkaline soils, or when the plant has been over irrigated or sitting in overly wet soil for long periods. Iron problems will cause the leaves to be reduced in size and the tree may drop older leaves early. This one is easy to fix though your yard maintenance company just needs to apply an iron fertilizer supplement.

Magnesium Deficiency – A magnesium issue will certainly be noticeable. Causing bright yellow blotches on leaves that will over time connect together to form large yellowed areas that may cover all of the leaf except for the tip and the base and the midrib. Really bay cases will defoliate branches and some leaves may begin to get a bronze hue. Defoliated stems often die back from magnesium deficiency however this problem is readily treatable. Simply water in Epsom salt, which can be purchased at any grocery store and the problem should be quickly corrected.

Manganese Deficiency – Manganese deficiency can be a little tougher for your lawn maintenance company to diagnose. It may be confused with the early stages of zinc deficiency. The leaf tissue will become a lighter green color than the veins of the leaf. However the color difference is not nearly as distinct as with other deficiencies like zinc or magnesium. The leaves will not be reducing size or shape but will be thinner and less robust. As with zinc, treatment is with a spray on the leaves. The spray should contain a manganese (Mn) solution.

We will follow up with another post on diagnosing citrus plants focusing on disorders.