All our Eucalyptus trees are container grown and are happy to be planted outdoors from March through to mid November in warm counties (October in cooler districts).
Watering is necessary a few times during the year, particularly during dry spells, until they are established. Never allow them to wilt—this is seriously bad news!
In cold areas, where you have an early autumn (like Scotland), it is good to plant from April through to June. Your Eucalyptus then have a full growing season to get established, before they meet their first winter.
In mild areas with low rainfall, or if you are planting in a field where it is difficult to water regularly, plant during the autumn; the soil is still warm and damp and the young tree will make good root and shoot growth before the winter.
Generally evergreens don’t enjoy being planted outdoors from the end of November through to February. However, if you want to take a risk and plant outdoors during this time, choose a frost free day, when the ground is not frozen and select a sheltered location. See how to plant for further advice. The 150 mm (6 inches) depth of mulch is vitally important. If very cold, cover the tree with a loose but secure tent of garden fleece, supported on a wigwam of bamboo canes or similar, until the weather improves.
Alternatively, over winter, you could adopt the following approach:
Unpack it and immediately pot up into an air-pot some 50-75 mm wider, using a good quality potting compost.
Keep the tree in a cool but frost free conservatory or greenhouse until March, with lots of sunlight.
Ensure the roots do not freeze.
Water, to keep the tree just moist, neither bone dry nor soggy.
When planted out in the Spring, your over-wintered tree will grow away with a very quick start.