When you have a toddler, you know that small packages don’t necessarily produce small things. Like the little kid who produces big noise, the "Dwarf Washington Navel" orange tree (Citrus sinensis "Dwarf Washington Navel") grows to only 6 to 8 feet tall but produces full-sized, juicy oranges. Better yet, the fruit is seedless, so you won’t be picking up spit-out orange seeds off the dining room floor. "Dwarf Washington Navel" orange tree is hardy to U.S. Department of Agriculture plant hardiness zones 9 through 10, but you can grow it in a container in other areas and bring it indoors for winter.
1 Water an in-ground orange tree with 1 1/2 inches of water in spring and summer whenever the soil is dry to the touch. Potted trees should get 1 inch of water and you may need to water more frequently because the soil will dry out quicker.
2 Fertilize the potted "Dwarf Washington Navel" with a citrus fertilizer, such as 5-2-6, at the rate of 1 teaspoon per 4 inches of pot diameter. Use 2 teaspoons for pots over 12 inches. Apply the fertilizer in late winter, late spring and late fall by sprinkling it on the soil beneath the tips of the tree’s branches. Scratch the granules into the top 1/4 inch of soil. Water the tree until water drains from the bottom of the container after fertilizing. Feed the ground-grown "Dwarf Washington Navel" orange tree at the rate of 2 pounds for trees up to 3 feet in height, 4 pounds for trees that are from 3 to 6 feet in height and use 6 pounds for trees that are 7 to 9 feet in height. Water the "Dwarf Washington Navel" tree with 1 inch of water after fertilizing.
3 Sterilize your pruning shears by giving them a five-minute soak in a solution containing 1 part of household bleach to 3 parts of water. Remove branches that cross over other branches and those growing straight up by cutting them back to a main branch. Do this pruning in late winter or early spring. Remove sprouts from the base of the tree by cutting them off. These sprouts are known as suckers and they won’t produce fruit and may drain energy from the tree. This is the only pruning the "Dwarf Washington Navel" orange tree needs.
4 Inspect the "Dwarf Washington Navel" orange tree regularly for signs of pests during the growing season and use horticultural oil spray to control them. Mix the oil with water at the rate suggested on the label. A general rule of thumb is to mix 5 tablespoons of oil into 1 gallon of water and pour it into a spray bottle. Water the tree before spraying and spray the oil on all surfaces of the tree, including the undersides of the leaves, to the point of runoff. ensure that all surfaces of the tree are covered with the spray.