Temperature

Best results from macadamias are achieved at temperatures between 20° and 25°c. Ground temperatures less than -1°c can damage young trees and frosts of -6°c will kill young trees while damaging flowers and foliage of older trees. Prolonged exposure to over 35°c will also have adverse affects and cause stress.

Rainfall

Average annual rainfall should be at least 1200mm, otherwise irrigation is required. The ideal amount for most soils is between 1500mm and 2500mm. Prolonged wet periods can cause trunk canker and blossom blight.

Altitude

The height above sea level influences both nut quality and the production of the trees. Strong winds can retard growth, flower set and yield and may even destroy trees.

Soil

Macadamias will prosper in a wide variety of soils with the exception of soil heavy in clay. Growers will generally look for well drained topsoil about 1 metre deep to a minimum 0.5m.