Olives
Edible olives can be grown as an ornamental tree or in a grove to harvest fruit for oil or eating. Olive trees are also tolerant of being grown in a large container in a warm courtyard (although don’t expect much fruit from potted trees). Once established, olives are very long-lived plants.
Olives are wind pollinated and many varieties fruit better with cross-pollination from a nearby compatible variety. Check pollination needs when purchasing plants. Also seek the variety that best suits your needs with advice from your local hardware or garden centre, as some varieties are best for oil production while others are best for eating.
Autumn to early winter when the fruit is plump and either dark green or purple-black is the time to harvest olives. Ripe olives are bitter and must be processed in brine before they can be preserved for eating.
Growing conditions
Aspect Sunshine is vital so select a warm, protected, north-facing spot.
Soil Any well-drained, slightly alkaline soil (pH 7-8) can grow an olive. Space productive plants at least 6m apart. Improve soil by applying Seasol Super Compost throughout the year.
Climate These are Mediterranean plants that do best in warm, frost-free locations but will grow from cool regions to the subtropics. Most olives require around 200 hours of chilling before flowering and fruiting occurs.
General care
Watering Once established, olives are very drought tolerant but benefit from deep watering as plants regain their leaves and during extended dry periods.
Feeding and mulching Feed in late winter or early spring throughout the growing season by applying a complete fertiliser for fruiting plants such as Seasol plus Nutrients Fruit & Citrus. Supplement with a liquid fertiliser such as PowerFeed PRO SERIES Fruit & Citrus every 2 to 4 weeks during the growing period (spring to autumn). Keep nearby grass mown.
Pruning Prune olives in winter after harvest to encourage new growth and spring flowers. Young plants benefit from early pruning and training to produce trees that have a single trunk and a framework of three to four main branches. Protect young trees from frost.
Watch out Although olives tend to be tough plants there are pests and diseases that affect olives. Major pests include olive lace bug and scale, which attack the leaves, and olive moth caterpillars, which attack leaves and flowers and can reduce fruit production. Pests can be controlled with EarthCare Enviro Pest Oil insect spray. Spray both sides of the foliage and repeat 14 days later if needed.
Diseases include leaf spots such as peacock leaf spot, anthracnose and root rots. These can be controlled with applications of organic fungicides. Also be sure to prune for good air circulation and grow the trees in well-drained soils.
Stressed trees are more susceptible to both pests and diseases so keeping trees growing strongly also reduces both pest and disease problems. If pests do occur, spray with EarthCare Enviro Pest Oil insect spray.
