Eucalyptus delegatensis

Cultivation Details

Eucalyptus delegatensis is native to the temperate climate of southeastern Australia, where it is found at elevations up to 1,500 metres. Summers are warm and can be dry, with most rainfall occurring in the winter months and a dry season that can be up to 3 months long. Mean annual rainfall is within the range 2,500 - 3,700mm, sometimes as snow; mean maximum of the hottest month is 21°c; mean minimum of the coldest month is 0°c, and there are generally around 70 - 100 frosts a year^[1]. When dormant, the plant can survive temperatures down to about -12°c, but young growth is more tender and can be severely damaged at -1°c^[2]. Requires a sunny position, succeeding in a wide range of well-drained soils of high to moderate fertility^[2]. The soils of the better forests in which it grows are moist but well-drained loams, especially those derived from granites or dolerites, but the mother rock may be a variety of sedimentary deposits in some places^[1]. Prefers a pH in the range 5.5 - 6.5, tolerating 5 - 7^[2]. A quick-growing tree that is easy to regenerate^[1]. It responds well to coppicing^[3]. Eucalyptus delegatensis occurs at a higher elevation than any other important timber species in Australia. The natural occurrences of the species are likely to have snow on the ground for several weeks each year^[1]. Annual wood production potential is 10 - 25 cubic metres per hectare^[2]. Eucalyptus species have not adopted a deciduous habit and continue to grow until it is too cold for them to do so. This makes them more susceptible to damage from sudden cold snaps. If temperature fluctuations are more gradual, as in a woodland for example, the plants have the opportunity to stop growing and become dormant, thus making them more cold resistant. A deep mulch around the roots to prevent the soil from freezing also helps the trees to survive cold conditions^[4]. Many members of this genus are remarkably adaptable however, and there can be a dramatic increase in the hardiness of subsequent generations from the seed of survivors growing in temperate zones^[4]. The tree has good prospects for planting in cool areas with a fairly high winter rainfall. It is one of the eucalypts resistant to frosts at least as severe as 9°c at the time of planting^[1]. It has beens introduced into South Africa in Zones E and G on a relatively small scale and showed good height and diameter growth, but did not become a preferred species. Several countries have good specimens but the main commercial plantations are in New Zealand. In New Zealand it is planted both in containers and as bare-rooted planting stock. With adequate root-pruning good seedlings are prepared and planted either by hand or by machine The trees grow vigorously but the leading shoot is attacked each autumn by the fungus Mycosphaerella nubilosa, which results in multiple leaders. One of these becomes the main stem early in the next growing season, but successive attacks of the fungus cause a series of large branches to develop on the trunk. This is not of great significance if the crop is being grown for pulpwood, but is more serious in the case of sawtimber^[1].