Citrus Care: How to Fertilize Citrus Trees

Citrus care consists of a number of tactics, like proper watering and monitoring for pest problems and proper fertilization. You need to be aware of the types of minerals your tree needs so you can fertilize it properly. It also means you should know the soil that the tree grows in and be aware of any potential inhibitors to the tree's ability to pull necessary nutrients from the soil.

Step 1 – Learn the Minerals Your Tree Needs

Most standard lawn fertilizers are insufficient as a citrus tree fertilizer. They don't contain the micronutrients that are needed, or they don't contain them in a strong enough concentration for optimum citrus care.

Citrus trees need the same nutrients as other trees, like potassium, phosphorus and nitrogen. But they also have specific needs that other trees don't have, including minerals like copper, boron, zinc and magnesium. The best source for these nutrients is in a specially formulated, slow-release citrus tree fertilizer.

Step 2 – Look into Mycorrhizal Fungi

Mycorrhizal fungi is a fungus that may not be present in the soil if other trees are not nearby. This fungus improves the tree's ability to pull needed nutrients from the soil. It can be added to the soil when a tree is planted, but can also be added later to improve the health of your tree.

Step 3 – Look at Potential Problems

If your trees have young leaves that are pale yellow or green, you may need a special solution in your citrus care plan. The leaves may either appear completely pale, or have distinct vein markings which are dark green. This may be a sign of iron deficiency. In extreme cases, new leaves are small and yellow, and may stop growing almost as soon as they appear.

Step 4 – Test the Soil's pH Level

Check your soil pH level to see if it's too alkaline. If the level is 7 or above, then the soil is too alkaline and your tree can't benefit from the minerals that are there. Chelated iron tablets put in the soil will cause iron to slowly be released and will lower the pH level as well as add more iron for your tree to absorb.

Step 5 – Fertilize

Complete citrus fertilizer comes in two varieties: one that you spray on to the tree to coat the leaves or one that is applied to the ground on the edge of the tree's drip line. Apply this complete citrus fertilizer once every month or two during spring and summer, and once every two or three months during fall and winter. Take care not to over-fertilize as this can cause smaller and less vibrant fruit.