Dwarf citrus trees are popular because they do not grow to be 15 to 20 feet tall and wide like their larger counterparts. They can be kept at a size which makes harvesting fruit easy. A dwarf citrus can even be grown in a pot. The fertilizer and application schedule will vary slightly from those grown in the ground.
Citrus trees put a lot of energy into producing fruit, and this makes them heavy feeders. Fertilizing keeps dwarf citrus trees healthy. Healthy trees not only produce more fruit, but they are more resistant to insects. Caterpillars, for example, can eat leaves on a lush tree without causing harm. A weak tree, however, may have fewer leaves and be more stressed as they are nibbled away.
Dwarf Citrus Planted in the Ground
Dwarf citrus trees grown in the ground are fertilized with slow-release granular fertilizer in March, June and August. Granular forms do a better job of reaching all of the roots than fertilizer stakes, which are placed at four places around the tree's drip line.
Gardeners can choose from both synthetic or organic varieties of fertilizer. When looking at the three numbers on a citrus fertilizer bag, the first number, nitrogen, will be the highest. A quality citrus fertilizer will also include micro-nutrients like zinc, copper and boron.
No matter the fertilizer, it is important to follow the application directions on the bag. They will depend on the size of the tree.
Dwarf Citrus Grown in Pots
Dwarf citrus grown in pots need to be fertilized more frequently than those in the ground. The reason is that they are also watered more. This depletes the soil of its nutrients. Look for a citrus fertilizer with twice as much nitrogen as phosphate or potassium. Follow directions on the fertilizer label that are specific to container-grown plants.
Plants grown in pots can, over time, accumulate salt in their soil from fertilizer. Periodically flush the soil with water and make sure it drains properly to remedy this.
If your dwarf citrus becomes nutrient deficient it will show up in its leaves. Leaves that are light green all over indicate a need for nitrogen. However, if the leaves are light green and the leaf veins are dark green that means that the tree is iron deficient. Liquid iron chelate can be purchased in concentrate form. Once mixed according to the directions it is applied to the leaves or directly to the soil.
Having your soil tested by an extension service can give specific information about nutrients. This is done primarily with trees grown in the ground. Those grown it pots are simply repotted with new potting soil.
Effects of Over-Fertilizing
Too much fertilizer is not good for your tree or, in the case of those grown in the ground, the environment. Trees that are over-fertilized will produce small fruit and often exhibit curled or discolored leaves. A professional soil test can be done to see what nutrient levels are too high.