To grow olive trees, plant the saplings in spring after the danger of frost has passed. Choose a location with well-drained soil and at least six hours of full sun each day. Water young trees to a depth of 2 feet using an emitter system placed 24 inches away from the trunk of the tree. Avoid mixing compost or other organic matter into the soil. If temperatures often drop below 30 degrees Fahrenheit, grow the tree in a container.
After planting the tree, cover the surrounding area with a layer of mulch to prevent weeds. In hot weather, install a second emitter 24 inches away from the opposite side of the tree.
Fertilize the tree in the spring after new growth appears, and every two weeks afterward throughout the growing season. Apply a nitrogen-rich mulch, such as pea hay, to the base of the tree at the beginning of spring.
When caring for potted olive trees, place the container outdoors in spring after the last frost of the season, and bring the tree indoors before the first frost of winter. Water the tree when the top 1 inch of soil is dry during the growing season. During autumn and winter, water the tree sparingly, and apply a balanced fertilizer to the soil once monthly.