The sweet olive (Osmanthus fragrans) is a small, evergreen shrub-like tree with dark-green leaves that have finely toothed edges. The sweet olive tree blooms during spring and summer with highly fragrant, small, tubular blossoms borne in clusters. In autumn, the sweet olive produces bluish-black, edible fruits. Growing to just 20 feet tall and wide, the sweet olive tree is cold tender and grows best in USDA hardiness zones 9 and 10, where winter temperatures rarely dip to 20 or 25 degrees Fahrenheit.
Select a planting site for your sweet olive tree that's in full to partial sunlight and in well-draining soil. Choose a location that has some protection from high winds and away from walkways to prevent staining them with the falling fruits.
Dig a planting hole that's the same depth as and twice the width of the sweet olive tree's root ball. Mix into the displaced soil some organic compost if your soil is nutrient-poor. Set the sweet olive tree's root ball into the planting hole with the tree standing straight up.
Back fill the planting hole with the displaced soil. Water the soil around the sweet olive tree deeply and thoroughly, soaking the soil generously to help it to settle around the roots.
Water your sweet olive tree deeply to soak the soil around the root ball once every month throughout the spring, summer and autumn. Water the tree deeply once each week during prolonged dry spells or droughts.
Feed your sweet olive tree once each year in early spring, well before the flowers emerge. Apply a slow-release, high-nitrogen fertilizer made for fruit or avocado trees, following the dosage instructions on the label.
Prune your sweet olive tree in fall after it finishes fruiting to remove all suckers growing from the base of the trunk. Remove the growth that produced fruits that year, because the olive tree won't bear fruit in the same place the following year.