How to grow Arbutus

There are several species of this evergreen shrubby tree, though by far the most widely cultivated is Arbutus unedo, also known as the strawberry tree. This small, attractive species is originally from the Mediterranean as well as some parts of Ireland, and is popular with gardeners throughout the world for its easy, adaptable nature and ornamental value.

Arbutus is one of the few plants to have fruits and flowers on display at the same time. The spherical fruits remain on the tree for a year; yellow for the most part until autumn when they ripen to red just as the next generation of bell-shaped flowers begin to bloom. Equally as attractive is the dark, leathery foliage and distinctive, peeling, reddish-brown bark.

Whilst the fruit is edible, expectations are raised perhaps a little too high by the common name – most people find them bland and uninteresting to eat, and in fact ‘unedo’ comes from the Latin for ‘I eat only one’. Better instead to simply enjoy the tree as an ornamental feature, leaving the fruits for the birds (who don’t seem to mind the lack of flavour!).

Key Information

Soil pH

Position

Hardiness

Where to plant Arbutus

For best results, plant in autumn or spring. An autumn planting can be done by those gardening in mild conditions (and broadly speaking, this is the southern half of the UK). For those liable to cold winters, it is best to wait until spring (generally the northern half of the UK). Planting can also be carried out in summer, though be prepared to water regularly.

Arbutus has a fairly slow growth rate, making it a well-behaved and low maintenance addition to a garden. The small eventual size of the more compact cultivars makes them a good option for smaller spaces, and a tolerance of salt and air pollution means the tree is a popular choice for coastal and urban gardens. Just remember to avoid planting too close to a path, paving area, or decking, as the fruits do drop and can be messy in these situations. Ideal spots include the middle or back of a sunny border, or edge of a woodland area.

The smaller, dwarf cultivars can also be grown in a large container.

How to plant Arbutus

For planting in the garden, dig the soil area removing any large stones and weeds and breaking up any lumps. Mix in some organic matter such as manure or garden compost. Rake level and firm with your heels. Rake level again.
Water plants well and allow to drain before planting.
A good tip is to dig a hole twice the size of the root-ball. Fill with water and allow to drain before placing in the plant.
Place the plant in the hole, ensuring the top of the root ball sits level with the surface of the soil. Too low and the plant may rot, too high and the roots can dry out.
Backfill with soil and firm in gently with your foot.
Soak well with water.
Mulch around the base with well-rotted organic matter.
For planting in containers, first choose an appropriately sized pot. The best practice is to start just a few centimetres larger than the rootball and increase in size every year or two. Always ensure there are plenty of drainage holes in the bottom.
If you are using a large or heavy pot, it can be a good idea to fill and plant it in situ to save yourself the trouble of moving once full.
Use a good quality potting compost with plenty of horticultural grit mixed in, and, if not already present in the compost (check the description on the bag) some slow-release fertiliser granules.
Start by partially filling the pot with compost; enough so that when placed on it the upper surface of the root ball is about 3cm lower than the top of the pot.
Infill all the space surrounding the root ball with compost, firming down with your fingers then adding a little more so the plant is held tight.
Pick up the container and lightly tap on the potting bench or ground a few times to help further settle the compost around the plant.
Soak well with water.
A mulch with horticultural grit will look attractive and help to prevent a ‘cap’ or crust forming on the top of the compost (something container plants can suffer due to the artificial nature of their watering).

How to care for Arbutus

Pruning and Deadheading

Arbutus falls into the RHS pruning group 1, which means it requires little pruning and is best left largely untouched.

The only pruning occasionally needed is a light tidy in late spring. Simply remove any dead, diseased, damaged, or badly placed branches (e.g., those rubbing against others, or growing towards the centre). Try to resist the urge to do any more than this as it is likely to spoil the natural shape of the tree.

Watering

Like all trees, arbutus should be regularly watered during its first year or two in the ground, after which it should only need watering in very hot dry spells. Try to avoid getting water on the leaves as this can encourage fungal diseases. When watering, give a deep, thorough soak then wait for the top few centimetres of soil to dry out before repeating (this encourages the formation of deep roots, as opposed to watering little and often which can result in roots growing mainly in the surface of the soil). To check this, wiggle your finger down into the soil until you hit damp.

Container-grown arbutus have less access to moisture so need regularly watering throughout every growing season. Again, water deeply and allow the top few centimetres of compost to dry out before repeating, though be aware that in the height of summer this can happen very quickly, and some container-grown plants may need watering every day (particularly those in smaller pots). From mid-autumn, the British climate tends to take over watering needs, though do remember to step in in the event of an unseasonably dry spell.

Feeding

On healthy, fertile soil, a mulch of well-rotted organic matter (i.e., a layer of manure or garden compost applied to the soil around the plant) should provide enough nutrients for your arbutus. This has the added benefit of suppressing weeds and locking in moisture. Mulch when planting, and then again every autumn or spring.

If you garden on poor soil or feel your arbutus could do with a boost, applying a general purpose granular feed to the surface of the soil and lightly working in (known as a ‘top dress’) can reap benefits. Do this when mulching – first apply the top dress, then cover with the mulch.

Container-grown arbutus is different, as these rely solely on the gardener for nutrition. Get off to a flying start by making sure you use a good quality compost with some slow release fertiliser granules mixed in. After this, carry out a replenishing ‘topdress’ annually in spring. To do this, simply scrape away the top few centimetres of compost and replace with a fresh load with the same fertiliser granules mixed in. Remember also to repot your arbutus every few years, going up slightly in size each time until it reaches full size. Expect the eventual container to be at least 45cm across.

Cold Protection

unedo is rated H5, which means hardy enough to withstand a winter throughout most of the UK, providing it is grown in a sheltered, well-draining spot (exposure to cold winds and/ or waterlogged ground can spell trouble for this Mediterranean species).

If you’re growing one of the more unusual species or hybrids, these tend to have a hardiness rating of H4. This means they should be okay in an average UK winter, though may struggle as you get further north, or in an unusually harsh winter. Again, positioning is key – it’s even more vital to plant these in a sunny, sheltered, well-draining spot. In addition to this, a fleece jacket is useful for protecting against the worst of the cold, and an autumn mulch will offer extra insulation to the roots.

Like all plants, those grown in a container can be more vulnerable to the effects of winter. It is worth moving these to a frost-free environment if you have one (e.g., an unheated greenhouse or cool conservatory). If not, insulate the container with hessian, bubblewrap, or similar to protect the roots (and reduce the chance of the pot cracking!), and move to a sheltered spot such as against a south-facing wall out of the wind. Use one of these handy fleece jackets to protect top growth whenever there is a cold spell forecast.

Pests and Diseases

Arbutus don’t usually suffer from serious problems, though there are a few pests and diseases that can be an unsightly nuisance.

You may spot aphids taking up residence on your arbutus. Our advice is that these are part of a balanced garden ecosystem and the best approach is to leave them to their natural predators (e.g. birds, ladybirds, and wasps). When numbers are so large, however, that their feeding starts to inhibit and disfigure growth, you may feel it necessary to act. Regularly blasting off with a hose or wiping away with a cloth or piece of kitchen paper can help to keep numbers down without harming other members of the ecosystem.

Scale insects look like small whitish brown barnacles on the leaves and stems. Again, they are best dealt with by natural predators such as birds, though you can also scrape them off by hand if you wish.

Spots or lesions on leaves and twigs, or premature leaf fall, can be caused by a couple of fungal diseases. Remove and dispose of affected plant material straight away, and ensure you give your arbutus the right care to avoid repeat problems i.e., watering during dry spells and mulching annually.

How to propagate Arbutus

The quickest and easiest way to propagate arbutus is by taking semi-hardwood cuttings in late summer to early autumn. You can try collecting and sowing seed, but these are notoriously tricky to germinate and can take many years to become a flowering and fruiting tree.

Select healthy, non-flowering shoots from the current year’s growth.
Snip cuttings off the plant, taking a longer piece than the ideal eventual length of around 10cm (to allow for trimming).
Put them in a plastic bag straight away to prevent drying out.
Fill a pot (or several, if you have a lot of cuttings) with a perlite-heavy compost mix (at least 50% perlite).
Trim the end of the cutting to just below a node (point at which leaves grow).
Remove lowest leaves, leaving 2-4 leaves.
If the remaining leaves are large, cut them in half with a sharp knife (to reduce water lost through transpiration).
Insert the cuttings into the compost and water lightly. Several cuttings can be put in the same container if there is enough space to do this without them touching.
Place in a warm, sheltered spot with indirect light (a cool greenhouse, conservatory, windowsill, or porch is ideal).
Water regularly until roots emerge out of the bottom of the container.
Gently remove rooted cuttings and pot them into individual pots. Grow on in a cool yet frost-free environment such as an unheated conservatory, greenhouse, or cold frame, until they are large enough to be planted out.

* Many plants carry Plant Breeders Rights and cannot be propagated for commercial purposes.

Common Arbutus questions

How do I grow arbutus in a pot?
Simply choose a compact, dwarf variety such as ‘Compact’ or ‘Elfin King’, and pot as described in our ‘How to plant arbutus’ section above. Water frequently and feed annually, as per our ‘Watering’ and ‘Feeding’ section.
How fast does arbutus grow?
Arbutus is considered to have a slow to moderate growth rate. Smaller cultivars usually reach eventual size in 5-10 years, whereas larger forms may take 10-20 years.