Arbutus unedo – Strawberry Tree
American gardens rely heavily on Asian plants sprinkled with some American natives, but are relatively light in European species. There are quite a few excellent garden plants from the area, though, and one of our favorites at the JC Raulston Arboretum is Arbutus unedo, sometimes called strawberry bush or just arbutus.
The genus Arbutus is comprised of about 14 species and a couple of hybrids. All the species are notable for their beautiful cinnamon-red or silvery bark. As members of the Ericaceae or heath family, they have panicles of white, urn-shaped (urceolate) flowers similar in size and shape to Pieris. Most of the species also bear showy orange to red fruits which are highlighted by the evergreen foliage. Arbutus species have an interesting geographical range as they are found in western North and Central America, southern and western Europe, Asia Minor, and north Africa.
Most species do not appreciate the high heat and humidity of our southeastern summers or the damp cold of our winters and as such are best grown in cooler, maritime or Mediterranean environments. The notable exception to this is Arbutus unedo, which ranges from Ireland to Portugal, Spain, France, Italy, Greece and over to Croatia, Bulgaria, Albania, and the Ukraine as well as Lebanon, Syria, Turkey and across the north African countries of Algeria, Morocco, and Tunisia. With such a wide range from the cool, damp of Ireland to sweltering north Africa, it is no wonder that this species can tolerate the variable weather of the southeastern United States.
Arbutus unedo is a handsome evergreen shrub or small tree which can slowly attain heights of 25'–30'. The branches and trunks are gnarled and twisted, giving a feeling of great age even to relatively young plants. The reddish-gray bark is fissured and can be very handsome with age. The foliage is a beautiful lustrous green, 2"–4" long with a serrate edge. It flowers in the fall, typically late September to November with some flowers appearing into the winter. The urn-shaped, white to sometimes pink-tinged flowers in 2" panicles make a nice display against the foliage. The ¾"–1" rounded, reddish fruits ripen about a year after flowering, providing the unusual (for a temperate plant) occurrence of flowers and fruit on display at the same time. Plants are self-fruitful and do not require a separate pollinator.
Strawberry bush is an easy-to-grow member of the heath family, tolerating both acid and somewhat alkaline soils. It performs best in relatively well-drained soils in full sun to part shade, and heavy clay soils should be amended for best performance. It is highly salt spray tolerant, making it a beautiful plant for seaside plantings. Over time, it will become much wider than tall, but will often send new shoots up from the base. Plants can be pruned up to expose the gnarled character of the trunks which resemble old Pieris and Kalmia (mountain laurel).
This species has been cultivated for centuries in Europe and the specific epithet "unedo" is derived from the Latin for "I eat one," denoting the edible aspect of the fruit, but perhaps also giving a clue its bland, somewhat unpalatable qualities. The bark has been used in tanning and the wood makes excellent fuel for fires, but is good for little else due to its twisted character. The fruits have been used to make and to flavor liquors, especially in Portugal. Perhaps most significantly, besides its obvious ornamental qualities, it is an outstanding nectar source for bees since it flowers at a time when many other flowering plants are shutting down for the winter, but temperatures are still warm enough for bees to be active.
Arbutus unedo can grow to a size that may make it difficult to fit into the typical home landscape, but there are several smaller forms which can be tried instead. 'Compacta' is an old form which is probably the smallest of the bunch, growing slowly to 4'–6' in a decade or more. It flowers through most of the winter and will set full size fruit. Unless it is grown almost as a bonsai, do not expect to enjoy the trunk and bark but instead use it as a low evergreen shrub. The cultivar 'Elfin King' grows somewhat larger, typically 8'–15' over time. It can be grown as an evergreen shrub or pruned up into a small tree, perfect for the smaller garden.