In late January and through February the river red gum in front of our house revealed a very welcome secret – it is carrying dual crops. The cycle of seed development usually lasts 2 years, from bud to seed fall, and healthy trees have two alternate cycles running simultaneously. That means the tree will always be producing seed each year in the peak seed production period. Our tree has mature fruit with open valves, indicating that the tiny pinhead-sized seeds have already been shed, while at the same time tiny buds are forming to develop into the next crop which will flower next summer and mature into seed in 2 years, in summer 2016. The flowers of November and December 2014 have transformed into immature fruit which will ripen on the tree during the year and mature into seed in summer 2015.
Summer (November to March) is generally the peak production season for red gums; in the Mid-North of South Australia it is November – December, and in the South Australian River Murray Valley it varies from November to March across individual trees and sites.
Mature red gum fruit shed their pinhead-sized seeds immediately if they break off the tree[/caption]
During the Millenium drought 2000-2010 in South Australia, river red gums reduced their reproduction, firstly only carrying one crop through a 2-year cycle, and then reducing the amount of seed produced by at least 10 times. The healthy growth on our local urban red gum gives hope for improved production and regeneration in river red gums across Australian landscapes this year.