The olive tree (Olea europaea) is a small tree native to the coastal regions of the Mediterranean Basin. Whether an olive tree can survive in a particular location is dependent on a multitude of variables. Olive trees require warm, sunny and dry weather conditions. Olive trees need a minimum of six hours of full sunshine daily. Olive trees can be grown outdoors in USDA Plant Hardiness Zones 8 and above. Gardeners in colder climates must grow olive trees in a greenhouse or containers that can be moved indoors during winter.
Olive trees grow best in well-drained, nutrient-rich, alkaline soil with pH levels of 7.0 to 8.5. Olive trees can tolerate mild saline conditions.Take a soil sample to your local county extension to test for compaction, permeability and pH levels. If pH levels are low, supplement the soil with garden lime until the desired pH levels are reached and maintained. Olive trees will grow in very poor soil, but they will reach their full potential if ideal soil conditions are available.
Olive trees do best in locations that receive 14 to 16 inches of rainfall a year. Commercial growers supplement water requirements with drip irrigation. Overwatering stunts the growth of olive trees and reduces the size and quality of the fruit. Excessive watering can kill an olive tree. Olive trees require good drainage and will not survive in areas of standing water.
Olive trees grown indoors should be watered when the soil is dried out to one inch below the surface.
Olive trees are slow-growing trees that retain their silver-green leaves all year long. Dwarf varieties of olive trees lend themselves well to container planting in Hardiness Zone 5. A Spanish variety, known as Arbequina, has a small, weeping form well adapted to container planting. Use a container large enough to allow the roots to spread out and breathe. The container should have excellent drainage.
If you plan to move your olive tree outdoors for the summer, wait until all danger of frost has past. Acclimate your tree to the outdoors slowly. Place the tree in a sheltered, shaded spot for at least a week before moving it to its sunny summer location.