One of the tallest eucalypts commonly used in landscaping, the blue gum (Eucalyptus globulus), ranges from 150 to 200 feet tall when mature. Windbreaks often use blue gum or other tall species of eucalyptus. Tall eucalypts are also common as highway plantings or in parks. Another use for these massive trees is to soak up water to dry out soggy areas. Other species that regularly top 100 feet in cultivation include river red gum (Eucalyptus camaldulensis) and manna gum (Eucalyptus viminalis).
A number of eucalyptus trees approach 90-100 feet in cultivation. Such trees provide a better match for residential properties than the taller species do. For example, lemon-scented gum (Eucalyptus citriodora) attains 75 to 100 feet in height when mature and can grow in close proximity to architectural structures. This species has lemon-scented foliage due to the presence of citronella in the leaves. Other moderately tall species include sugar gum (Eucalyptus cladocalyx) and swamp mahogany (Eucalyptus robusta).
Small yards call for compact eucalypts that remain under 90 feet when mature. For example, dwarf blue gum (Eucalyptus globulus v. compacta) and Sydney blue gum (Eucalyptus saligna) both grow to about 70 feet, while Mindanao gum (Eucalyptus deglupta) is slightly taller at 80 feet. In contrast, candle bark gum (Eucalyptus erythrocorys) grows only to about 13 feet tall. Other smaller tree eucalypts include silver-topped gimlet (Eucalyptus campaspe) at 15 to 25 feet, bushy yate (Eucalyptus conferruminata) at 20 to 30 feet, and ghost gum (Eucalyptus pauciflora) at about 40 feet.
Although the prototypical eucalyptus grows as a tree, a number of species grow as bushes or shrubs. Some of the most diminutive eucalypts never get above 10 feet tall. For instance, Kruse's mallee (Eucalyptus kruseana) ranges in height from 5 to 8 feet and is described in "Sunset Western Garden Book" as "almost a ground cover." Many mallees can achieve heights typical for small trees, but they retain a bushy, multi-stemmed growth habit. Two examples are blue-leafed mallee (Eucalyptus polybractea) and oil mallee (Eucalyptus kochii), both growing to about 13 feet.