Ask Mr. Smarty Plants

The short answer to your question is: very fast! The Eucalyptus spp., no matter where they grow, are noted for their rapid growth rate and can attain up to 90 percent of their height within 15 years. It isn't unusual for ten-year-old trees to reach 90-100 feet. The rate of growth will vary depending on species. For Eucalyptus robusta, J. R. King and R.G. Skolmen report that after 10.25 years the mean height of all the trees in one of Florida's first eucalyptus plantations was 54.4 ft. (16.6 m). For Eucalyptus grandis G. Meskimen and J. K. Francis say a growth rate of 6.5 ft/year (2 m/yr) is common and a maximum of 13 ft/yr (4 m/yr) has been reported. You can see a comparison of growth rates of three species, E. grandis, E. camaldulensis, and E. amplifolia, in Table 2. Guidelines on the establishment of three Eucalyptus species in Florida in "Eucalptus--Pulpwood, Mulch or Energy Wood?" by D. L. Rockwood from the University of Florida , IFAS Extension. You can also find a comparison of growth rates of E. amplifolia, E. grandis and cottonwood trees from Planet Power sponsored by the Florida Energy Office and DOE/SSEB (U. S. Department of Energy/Southeast Biomass State and Regional Partnership).