Eucalyptus trees are popular for their silvery foliage, distinctive bark and the fresh scent released when leaves are handled. They're also among the easiest ways to make a small garden feel instantly different. But there is one serious drawback: the wrong eucalyptus can grow far larger than you expect. Before planting one, think about its mature size and whether you're willing to prune it regularly.
Choose the species before buying
Eucalyptus is a large group, mostly native to Australia. Species vary enormously in height, hardiness and growth habit. The familiar cider gum, Eucalyptus gunnii, is widely sold, but it can develop into a substantial tree if left alone.
The snow gum, E. pauciflora subsp. niphophila, is another option for suitable UK gardens, with striking bark and relatively good cold tolerance. Some less hardy species need a sheltered position or frost-free protection.
Check the plant's eventual height, not its size in a garden-centre pot. The RHS notes that eucalyptus can put on a metre or more of growth annually under favourable conditions.
Where should eucalyptus be planted?
Most species need full sun and freely draining soil. A site sheltered from strong, cold winds is preferable for young trees, particularly in exposed northern gardens.
Don't place a vigorous eucalyptus immediately beside a house, boundary wall, drain or small paved courtyard without considering its future root system and canopy. Large trees draw substantial water from the soil, and a plant that looks manageable now may be expensive to remove later.
Avoid persistent shade and sites that remain waterlogged through winter. A raised, well-drained position can help in gardens with heavy soil, although planting on a mound doesn't solve an unsuitable location beside buildings.
When is the best time to plant?
The RHS recommends planting eucalyptus in spring or summer. This gives young trees time to develop roots before winter winds and cold weather arrive.
Choose a healthy specimen, ideally a relatively young tree rather than the largest container plant available. Smaller eucalyptus plants often establish more successfully because they adjust their roots to the surrounding soil before the top becomes heavy.
Water the pot before planting. Avoid taking a newly bought tree from a protected nursery into a freezing gale; gradual acclimatisation is helpful when conditions have changed sharply.
How to plant eucalyptus in the ground
Remove weeds from around the planting position and dig a hole no deeper than the rootball, but wide enough to loosen the surrounding soil. Set the tree at the same depth it occupied in the pot.
Unlike many flowering shrubs, eucalyptus generally doesn't need a rich planting hole full of manure or garden compost. The RHS specifically advises against enriching the soil this way when planting. Healthy contact between roots and existing soil is more important.
Backfill, firm gently and water thoroughly. Mulch over the root area on damp soil to reduce weeds and evaporation, leaving a gap around the trunk to discourage rot.
The RHS advises leaving small newly planted eucalyptus unstaked because they establish stronger roots when they can move naturally. Avoid choosing an exposed site in the first place; large or unsafe trees need professional assessment.
Can eucalyptus grow in a container?
Some compact types and regularly pruned specimens can grow in large pots, but they need substantial root room. The RHS suggests containers about 60cm across or larger for suitable eucalyptus.
Use a free-draining potting mix and a heavy, stable container that won't tip during wind. Check moisture regularly because leaves keep using water even when the garden is dry.
A container restricts the roots, but that does not guarantee a permanently miniature tree. Repotting, root management and pruning may still become necessary, and some species eventually outgrow practical pot culture.
In winter, position a pot where drainage remains good. Standing it on feet can keep holes clear and prevent the compost from remaining soggy.
Watering while the tree establishes
Young eucalyptus trees need help through dry spells after planting. Water deeply enough to reach the rootball and surrounding soil, then let the surface begin to dry appropriately between waterings.
Once established in suitable ground, many eucalyptus species need less supplementary watering. However, extreme drought can stress even a mature tree, particularly on shallow soil.
Container plants are different. They may need frequent checks during warm weather because their compost volume is limited. Avoid both repeated severe drying and leaving roots standing in water.
Do eucalyptus trees need feeding?
Usually not much. Eucalyptus is adapted to conditions that may be relatively low in nutrients, and rich fertiliser is rarely the solution to poor growth.
If a tree is pale or struggling, investigate drainage, temperature, exposure and root condition before feeding. A species unsuited to local winter conditions will not become hardy because it receives extra nutrients.
A suitable surface mulch may improve soil conditions without the need for heavy feeding. Keep the material clear of the trunk.
Why eucalyptus leaves change shape
Young eucalyptus plants often have rounded, silver-blue leaves prized by florists. As a tree matures, some species develop longer, narrower adult leaves.
This is normal. It doesn't mean the tree is sick or that you've been sold the wrong plant. Regular pruning can encourage fresh juvenile foliage, which is why some gardeners coppice eucalyptus to supply stems for flower arrangements.
Pruning, coppicing and pollarding
Coppicing means cutting an established plant low down so it produces fresh stems from near the base. Pollarding involves cutting branches back to a framework higher above the ground. Both can be used on suitable eucalyptus, but timing, species and plant health matter.
These are major pruning techniques, not jobs to improvise with a tall tree and a ladder. The RHS recommends checking the species and using appropriate methods. Large, mature trees may need professional arboricultural advice.
If you're growing eucalyptus mainly for young decorative foliage, choose a variety suited to regular coppicing from the start. For a specimen tree, lighter corrective pruning may be better than severe repeated cutting.
Remove obviously dead, damaged or dangerous branches promptly, using a professional for work beyond safe ground-level reach.
Preparing eucalyptus for winter
Established hardy species generally cope with ordinary British winters in suitable positions. Young plants can still suffer in harsh winds and cold exposed spots.
Protect a newly planted tree from winter waterlogging. In containers, move the pot to a sheltered location, keep drainage open and avoid leaving wet compost frozen for long periods.
Don't wrap the whole canopy in non-breathable plastic. If frost protection is needed for a particularly vulnerable plant, use appropriate horticultural materials and allow air movement.
Common eucalyptus problems
Leaves turn brown after winter: Cold winds, frost or damaged roots may be responsible. Wait until conditions improve before deciding how much live growth remains.
The tree leans: Check for wind rock, poor staking or a rootball that hasn't established securely.
Growth is unexpectedly vigorous: The species may be naturally large. Plan suitable pruning early rather than allowing it to outgrow the site.
Leaves wilt in wet ground: Poor drainage may be interfering with root function.
Branches are too high to prune safely: Don't climb into a large eucalyptus. Use a qualified tree professional.
The right tree in the right place
Eucalyptus can be an attractive, long-lived feature where there is enough room. Select a suitable species, give it sun and drainage, water it through establishment and decide early whether you want a specimen tree or a regularly pruned foliage plant. Most long-term problems come from choosing a tree too large for the garden, not from complicated day-to-day care.
Source
Royal Horticultural Society: How to grow eucalyptus.