Eucalyptus trees are pruned when they are young in order to shape them into their final, mature form. Trim older trees only if necessary to remove dead or diseased wood. There are several different methods used to prune eucalyptus trees, depending on their purpose in the landscape.
Prune eucalyptus trees in the form of a hedge. Plants are spaced 3 to 4 feet apart in the hedgerow and are individually pruned for shape. When the hedgerow is 2 years old, prune off 1/3 of each individual tree's height. Shape each of the remaining trees into a pyramid by trimming off the tips of the side branches. Every year, remove 1/4 of each tree's height in the same manner and reshape into a pyramid.
Prune your eucalyptus to control its height using a method called "coppicing." To do this, prune all trunks to a height of 18 inches and cut off all side growth. This will encourage the plant to bush out and produce lush growth quickly. Use this method on eucalyptus trees that are at least 2 years old.
Prune 3 to 6 year old eucalyptus trees using a method called "pollarding." Cut off the top of the tree so that the trunk is 6 to 10 feet high. Do not remove the lower branches. This encourages the tree to branch out and is used to most often to shape a eucalyptus tree as a focal point in the landscape.
Prune your container grown eucalyptus trees once a year using the "coppicing" method in Step 2. This will keep them at a manageable height of between 4 and 8 feet. The best time to prune container-bound eucalyptus is in the spring. Prune eucalyptus growing in the landscape in summer.
The best time to prune eucalyptus trees is in hot, dry summer weather; they recover more rapidly.
Do not prune eucalyptus trees during extremely humid conditions; they may develop a fungal infection.