How long it takes for a eucalyptus tree to grow depends on the specific variety and things like soil quality, access to water, and climate. Eucalyptus trees are known to have a moderate to fast growth rate. As an example, The Forest Red Gum, can grow up to 1-2 meters (3-6 feet) per year until it reaches maturity. The Forest Red Gum will eventually grow to 20-50 meters (65-165 feet) over the course of 20-50 years, depending on conditions. Young eucalyptus trees can provide some food and shelter for koalas, but if given the choice, they prefer more mature trees with an abundance of leaves and more canopy for sleeping.