Nimbin Plant Selection Guide

Published in The Nimbin Good Times March 2006

David McMinn

We have had good rains, the high heat of summer is over and now is an excellent season to plant trees. Amongst your plantings remember to include numerous eucalyptus trees for the Koalas in our area. These delightful animals are found at Blue Knob and Tuntable Creek, but their populations appear to be quite limited. My neighbours at Blue Knob have occasionally seen them on their properties, but we have never had the thrill. In NSW, the species has been classified as vulnerable and the state's population is in decline. The greatest threat to the continuing survival of the species is the loss of habitat, but you can do your bit by planting suitable trees for Koala forage. 

Eucalyptus Species

Koalas eat about half a kilogram of gum leaves every day. However, these may contain toxic compounds, are hard to digest and have limited nutritional value. This poor diet means that the animal must conserve energy, so it sleeps for most of the day and looks for food in the evening. Koalas are fussy eaters and, in our region, they obtain the bulk of their food from only five Eucalyptus species.

Flooded Gum (E grandis) 30-40m. Very fast growth in moist soils - you will have a forest in several years - and the whitish columnar trunks are very attractive. The timber is now sold under the more saleable name of Rose Gum.

Tallow Wood (E microcorys) 20-40m. Growth is fast in drier soils. Frost tolerant. The timber can be used as fence posts, for flooring, in building construction and so forth.

Grey Gum (E propinqua) 20-30m. Moderate growth with a preference for drier soils. We planted 100 trees of this species on our farm, but only a few survived. Unless you get positive feedback from other growers, avoid planting Grey Gum in our area. Drier locations may be more suitable. 

Swamp Mahogany (E robusta). 20-30m. Fast growth. It is best sited in well drained soils near waterlogged areas. Do not plant in swamps as the trees will die, despite what its common name would suggest. Frost resistant.

Forest Red Gum (E tereticornis) 10-30m. It has slow to moderate growth, but this may be speeded up with a little slow release fertiliser. Light to heavy good soils. It likes to be planted near waterlogged areas. Seedlings do not cope well with frost. 

These Eucalyptus species are also excellent for other wildlife, as the flowers provide nectar and pollen for birds, bees and fruit bats. 

The trees will ultimately grow very large and must be sited sensibly. They should be planted well away from power lines and buildings. Do not locate them in areas where they can block out your views or create a fire hazard for you or your neighbours. We have planted hundreds of Koala food trees around the farm, mainly on the ridges and as wind breaks well away from the house. Many of the trees are now quite large, but we have yet to see a single Koala. We also have never heard them during the mating season (September to January), when the males emit pig-like grunts and growls and the females high pitched trembling sounds. Perhaps one day......

There are also several secondary food trees, such as Sydney Blue Gum, Blackbutt, Brush Box, Broad Leaf Paperbark and Grey Ironbark.

Other things you can do 

To prevent dogs mauling koalas, do not allow your dog to roam at any time and especially keep it confined at night when Koalas are most active. Restraining your dog is essential if you have Koalas in your area.

Become involved in environmental organisations that work to restore native habitat.

Slow down and take extra care when driving through well vegetated areas, especially those areas sign-posted for native animals.

If you do hit a koala when driving or find a sick, injured  or dead animal, please stop and help. Friends of the Koala may be contacted on 66221233.

All the best with your Koala tree plantings.