Full-size orange trees can grow up to 50 feet in height and spread. This size makes it difficult to grow the trees in small yards. Many gardeners choose dwarf orange trees--smaller versions of the originals, with similar qualities. Like most citrus, oranges and their dwarf counterparts need careful fertilization for the best fruit.
According to Four Wind Growers, dwarf orange trees produce the same size blooms and fruit as full-size orange trees, but stay smaller, at 8 to 10 feet. Because these are dwarf trees grafted onto standard orange tree roots, they require similar care to standard orange trees.
Like standard orange trees, dwarf oranges require direct sunlight for six to eight hours every day. Oranges won't bloom or bear fruit without enough direct sunlight. Fertilizer will not compensate for a lack of direct sunlight.
Orange trees require deep, rich and fast-draining soil for both drainage and nutrition. Organic compost is an easy way to provide an orange with natural fertilizer, while keeping the soil loose and well drained. Because compost is organic, it will not "burn" the orange tree if you apply too much.
Purdue University notes that orange trees have precise nutritional requirements. The best fertilizer for a dwarf orange tree is balanced organic or 10-10-10 fertilizer, with additions of extra nitrogen for fruit harvest.
All fruit trees do well with a feeding in early spring to boost summer growth, and another feeding halfway through the summer to encourage fruiting. Purdue University suggests a third feeding after harvest to increase orange tree productivity.