Monkey puzzle trees, also known as Araucaria araucana, are needled evergreen trees that are prized for their open, pyramidal form and horizontal upward-arching branches. Native to Chile and Argentina, monkey puzzle trees thrive in climates with mild summers and are hardy in most parts of the UK. Despite their odd and showy appearance, monkey puzzle trees require simple care.
Plant monkey puzzle trees in full sun locations that receive six or more hours of direct sunlight per day to help ensure healthy growth and development. In their native Chile, monkey puzzle trees can be grown successfully in partial sun locations that receive as little as four hours of direct sunlight daily; elsewhere a partial sun location is unlikely to provide the light your trees need to grow and thrive.
Water monkey puzzle trees weekly whenever rainfall fails to provide them with at least 2.5 cm (1 inch) of moisture per week. Reduce the frequency of watering during the cooler autumn and winter months -- provide just 2.5 cm (1 inch) of supplemental irrigation every two weeks or as often as necessary, to keep the soil moist, but well drained.
Fertilise monkey puzzle trees monthly from early spring through summer using a half-strength solution of a water-soluble fertiliser product that has been specially formulated for use with evergreen trees. Follow the application instructions on the fertiliser packaging to avoid over-fertilisation, which may damage the roots of your trees.
Check monkey puzzle trees for diseased, winter-damaged or dead branches each year in the very early spring. Remove problem branches promptly as they can cause the health of your trees to deteriorate. Cut the branches with sharpened and sterilised loppers; make your pruning cuts at the edge of the branch collar.
Monitor monkey puzzle trees for increased insect activity; monkey puzzle trees often experience problems with common pests such as mealybugs, thrips, spider mites and scale insects. Treat affected monkey puzzle trees with horticultural oil or a garden insecticide if you notice the health of your trees declining due to insect infestation. Follow the application instructions on the horticultural oil or insecticide packaging for best results.
Periodically mist the foliage of your trees with water. Monkey puzzle trees perform best in humid climates.
Monkey puzzle trees drop branchlets and sharp, pointy leaves year-round. Wear gardening gloves when cleaning up monkey-puzzle tree debris to avoid injury.