Black box trees flower mostly in summer, right? Wrong!! At least this year, for the first time since the start of monitoring black box in 2004, the majority of trees are in full glorious flower in winter!
The working hypothesis was that the majority of black box (Eucalyptus largiflorens) flowered annually in summer, timed to make the most of soil moisture after floods which naturally occurred in late spring-early summer every 2-3 years. The minority which flowered in winter appeared to be geared to moisture supplied by winter rains.
Black box trees grow at higher elevations on Murray-Darling floodplains and suffered severe die-back and death during the Millenium drought 2000-2010. They have been recovering since the life-giving floods of 2010-2012. Mass growth of black box seedlings is being nurtured with environmental water at several sites in the South Australian Riverland. Nature Foundation SA’s Water For Nature program has identified sustaining the seedlings as a priority, since the last major regeneration event to survive in significant numbers followed the 1955-56 floods.
Whatever the reason for the current spectacular flowering season, whether it is a return to ‘normal’ after years of drought, or the effect of unusually high local rainfall in January and May, this means that there will be mass seed available in 12 months’ time, when the ripe fruit open and drop their seed. That will be a key time to monitor soil moisture, and to add environmental water if needed to encourage fresh germination of black box to fill in the gaps in this community, currently dominated by aging stressed trees with pockets of 5 year old seedlings.
The dense clusters of cream flowers and healthy silver-green foliage indicate trees on the road to recovery, with dense pockets of thriving black box seedlings offering hope for the future. Environmental water used at these locations is bringing community benefits in improved amenity and landscapes on riverfronts to attract visitors, with benefits for tourism businesses and local traders.