One of our most popular Facebook posts at the nursery of late, has been the discussion about all of the beautiful Grey Gums (Eucalyptus propinqua ) after they had shed their bark due to the deluge of rain that we experienced over the last few weeks.

As the trees usually shed their bark much later; usually in February, by which time the usual hot and dry weather has faded the bark to light pink/grey. By shedding early, they have retained their inner bark’s rich colour.

This discussion prompted me to do a bit more research about our local endangered species; – Blinky Bill, who regularly dines upon these native trees.

It would seem that Koala’s are not quite the low maintenance leaf-eaters that we presume them to be! While there are particular species that they like to eat, Koala’s also enjoy different tree species for other recreation. As I have found on my own property, Koalas often prefer a more-dense canopy for shade throughout the day- while they get their beauty sleep. Our resident male is often perched in our spotted gums (Eucalyptus maculata) and we have also seen them lounging in palm trees at Port Macquarie.

As it turns out, not all eucalyptus trees will cut the mustard however. Grow the right variety in the wrong PH soil or the incorrect climate, and the tree may produce toxins in the leaves like terpenes and phenols. This changes the flavour and the little furry guys won’t eat them- no matter how many you have planted.

This is because they have a complex habitat selection of food trees, which requires them to balance nutrient and water intake against those toxins. Tender tummies indeed.

Thanks to climate change, drought and fire, more than 2 million acres of habitat has died since August 2019. It has become quite urgent that we really address this situation or the koala’s will be threatened with extinction by 2025.

Koala’s feed and occupy trees with a girth of no less than 20-30 cm, and they also need a home- range area which is sired by one male Koala for any number of females. This equates to 25-30 trees per hectare to be able to support that colony. Breeding often needs a 5 hectare home-range, so things start to look a lot more complicated than just planting a few trees here and there.

As more males are born into the colony, they will be forced out by the alpha male and they may have to travel up to 40-50 km away to start their own home range, taking some younger females with them. This also helps with the gene pool.

Add to that, Koala’s often change their food preferences too. This requires a mix of both Primary and Secondary food trees to be planted. This reduces the need to travel which we know comes with many risks, like injuries from cars and dogs.  

So, it looks like half a dozen trees here and there is just not enough to sustain food for our Koalas as we move forward into the future, while subdivisions along the East coast flatten their forests for retirement living.

So, I make this suggestion. Have a family member on a farm, or a neighbour with more acres? Buy the trees and cultivate them together. 

Time is running out for Blinky………..

Depending on availability and season, we stock these varieties in tube stock size.

Eucalyptus species suitable for the Manning Valley and Great Lakes areas –

Eucalyptus Propinqua	Small fruited Grey Gum	Suits well drained soil, gravel-ridge soil structure.	Secondary food
Eucalyptus Robusta	Swamp Mahogany	Suits wetter soils and gullies.	Primary food
Eucalyptus Microcorys	Tallowwood.	Suits well drained soils and ridge-gravel sites.	Primary food
Eucalyptus Tereticornis	Forest red gum	Suits river-banks, low hills and plains, average drainage.	Primary food
Eucalyptus punctata	Grey Gum	Coastal areas, sandstone/shale, well drained soils.	Secondary food

Tanya
Wingham Nursery & Florist
02 6553 4570

References:

DPI NSW    
NSW Forestry Corporation 
 nefa.org.au 
National Resources Commission
savethekoala.com