This genus is one of the most useful of our introduced exotics. True, it is sometimes found to be a nuisance, especially when the common Blue Gum has been planted in good soil along narrow streets and its roots have been within reach of a poorly laid sewer, for it will find out poor work more quickly than most sewer inspectors, the tiniest crack or the smallest pinhole being surely discovered by the roots of this rampant gross feeder. Should a pin-hole be left in the sewer pipe, the Eucalyptus quickly enters and in a very short time fills the pipe so full of roots, that it stops up the entire pipe, sometimes for the distance of a hundred feet. This is not the situation for a Eucalyptus of the globulus variety, but the tree merits a place in the landscape and that place should be a prominent one. In an out of the way corner which cannot be used for any other crop, or, on some high knoll where shelter is needed and little else will grow, Eucalyptus globulus (Blue Gum) can be planted to advantage, but there are many other species which may be introduced and which give fine effects even in the most choice collections.
For instance take Eucalyptus piperita: when grown in a suitable place it is as graceful as the Birch; and no Willow has a finer drooping effect than Eucalyptus saligna with its willow-shaped leaves; or again, the red-flowering variety (Eucalyptus leucoxyla, var. macrocarpa), when laden with its bright-pink, myrtle-like blossoms has a most striking effect in the landscape, while the scarlet-blooming Eucalyptus ficifolia is very effective even in small gardens as are also Eucalyptus cornuta (yellow flowered), Eucalyptus tetragonus (crimson-flowered and a dwarf grower), and Eucalyptus Landsdowniana (also a dwarf grower with small red flowers and rather broad dark-green leaves). Still another dwarf grower of bushy habit is the Eucalyptus pyriformis so named on account of the pea shape of the calyx; this species has pink flowers and is said to grow in the poorest lands" such as in the dryest regions of South Australia. Eucalyptus corymbosa and its varieties give graceful foliage effects where room can be spared for them. Eucalyptus viminalis is a species which is almost indispensable where trees of a graceful or semi-drooping habit of growth are desired. Where the rainfall is light and a symmetrical well-balanced top is desired, the Eucalyptus cory-nocalyx can be safely recommended as it has been proven beyond a doubt to survive our dryest seasons, even when most of the strong vigorous growers, like Eucalyptus globulus and Eucalyptus amygdalina, have died off for lack of sufficient moisture. Eucalyptus amygdalinais said to be the tallest-growing tree in the world, attaining, in the valleys of its native country, to the height of between five hundred and six hundred feet; it has rather dense foliage and a bright-green leaf. Eucalyptus sideroxylon (the iron bark) is one of the most desirable for planting in our interior valleys as it stands drought well; it is best known by its dark-brown iron-like persistent bark, red flowers and light-gray foliage; planted in group-form it gives a most striking effect in the landscape.
There is a great variety of this family of Australian trees, and, where space can be secured or spared, that space can be profitably used for planting the different species of this very ornamental and useful genus.
Propagation is by seeds. Sow the seeds in boxes or pots filled with light sandy soil, in March or early in April; cover the seeds lightly with sandy leaf-mold, and water thoroughly. Place in a cold frame and shade lightly during hot sunshine until the seeds have germinated; as soon as they have made four leaflets remove the sash from the frame and replace it with a lathed cover to protect the seedlings from strong sunshine and also from the ravages of birds. When the plants are two inches high, transplant them into boxes about four and one-half inches deep filled with good strong loam, planting them about three inches apart. Return them to a situation similar to the one from which they were taken; give them a good watering and keep them shaded during strong sunshine for a few days, afterwards gradually exposing them to the open air. Plant them, in March or April, where they are to remain.