Strawberry Tree, also called Irish Strawberry

Arbutus unedo

Origin:

It is native to Asia Minor and Mediterranean countries where it can be found growing wild.

Climate:

It is a sup-tropical species adapted to long hot dry summers and wet winters; nevertheless it can grow in the wet Summers of western Ireland. Mature plants are drought hardy and will survive down to -15°C.

Plant Description:

An evergreen shrub or small tree, 3-6m tall and about the same width, with reddish-brown bark that becomes flaky with age. The dense dark green leaves are alternate, leathery, elliptic, 4-10cm long, 2-3cm wide and have a serrated margin. Seedlings have a long taproot so take care when transplanting; when mature it is this feature which enables it to withstand dry periods. They develop a mycorrhizal association which assists their nutrition.

Relatives:

Ericaceae Family. Blueberry, cranberry.

Soils:

Provided the soil is well-drained it will grow in all soil types. It prefers an acidic pH but will still grow if slightly alkaline.

Propagation:

Seeds, cuttings and grafting can all be used. Seeds need stratification at 4-5°C for 3 months before sowing.

Cultivars:

Most cultivars have been selected on a non-fruiting basis as it is very commonly grown as an attractive ornamental plant. However some of these do produce tasty fruit and vegetatively propagated plants will fruit faster and more predictably than seedlings. Some such cultivars include Compacta (dwarf), Elfin King and Rubra (pink flowers). Studies focussed on optimization of fruiting qualities are virtually non-existant.

Flowering and Pollination:

Flowers are perfect, fragrant and appear in 10-30 flowered drooping racemes. The 5 creamy-white petals are joined nearly their full length to form an urn, inside which are 10 stamens and a 5 locular ovary. Pollination is by bees which are strongly attracted to the flowers.

Cultivation:

Normal care when young. The plant does best in full sun but will still fruit with some shade. It usually needs little additional fertilization, but will crop better if watered in dry periods.

Wind Tolerance

Reasonably wind tolerant if not overly hot and drying. It is even used in some places as a low wind break.

Pruning:

It usually develops into a well-rounded dense canopy that needs little attention. Trees may give better yields than bush forms.

The Fruit:

The fruit is a globose berry, 1-2cm in diameter, with a pebbled skin that begins green-yellow and then changes to bright red when ripe, with 5 small seeds within the flesh. Vitamin C is 2-5 times that of an orange, sugars can be 10-30% depending on variety, and health-promoting antioxidant levels are amongst the highest of 28 other fruit analysed in one study.

Fruit Production and Harvesting:

Fruit take about 12 months to mature so you can have both fruit and the current season's flowers on the tree at one time. Normal harvest time is late Autumn/Winter. Only fully coloured fruit should be picked over an extended season. They do not store or transport well.

Fruit Uses:

Fruit flavour for seedling-grown plants is often bland and they are consequently processed, but the better varieties are enjoyable as is. Best flavour is attained when totally ripe, with reduction in tannins and increases in sugars.

Pests and Diseases:

These are not a major problem, but aphids and Phytophthora can attack plants and birds are attracted to the fruit.

Comments:

The strawberry tree is a most attractive, small evergreen species which looks beautiful in autumn/winter with masses of both flowers and bright red fruit amongst its dense green foliage. If you plant one for eating fresh, try and ensure it is a graft or a cutting from a plant you know produces tasty fruit. Madrid’s Coat of Arms contains a bear and a strawberry tree!