There are three Arbutus species that every California landscape architect should know: A. menziesii, A. 'Marina,' and this one, A. unedo 'Compacta.' Of the three, only A. menziesii is native to California, but the other two are also native to Mediterranean climates. Well, some references, including Sunset, claim our subject, A. unedo 'Compacta,' is native to Southern Europe (therefore Mediterranean) and Ireland. What's up with that? There must be a study out there to explain, but I did find this reference from Catherine Nelson, Center for Urban Horticulture:
Evidence of tree pollen preserved in bogs suggests that the tree was introduced to Ireland in the form of seeds some 4000 years ago during widespread immigration of the Beaker culture in Europe.
A. unedo, or strawberry tree (we will get to the common name in a moment), is considered to be a small tree, but when we look at the cultivar, A. unedo 'Compacta,' calling it a tree is misleading. Most arborists accept classifying trees versus shrubs is based on mature size, but that height is variable between authorities. For example, as an arborist I have always understood that a plant must reach at least thirteen feet or more to be classified as a tree. Others might say only ten feet, and still others will determine classification by form, such as when a shrub, like a rose, is grafted to become a tree rose. So, for me to call this compact strawberry "tree" a tree when it only reaches about ten feet, that is asking the world! In other words, I would classify it as a shrub regardless of its appearance. I will still categorize it here under both shrubs and trees, because people often associated it with trees or design with its tree form in mind.
This compact form of strawberry tree is an attractive plant. It is commonly grown as a multi-trunk, and with age will lend itself to a sculptural form with exfoliating bark. All Arbutus noted here have beautiful, tiny, bell-shaped flowers in hanging clusters that are either pink or, in the case of A. unedo 'Compacta,' white, followed by the real show stopper, the fruit (shown above). As the fruit continues to age, the color will change from green to yellow, orange, and ultimately red like a strawberry (now we know the reasoning behind the common name). When the fruit is red it is edible but tastes nothing like a strawberry. Mild in flavor, some say notes of pear, I tend to eat them right off the tree....er, shrub.
A few specimens at West Valley College appear to be thriving without irrigation (shown below). Unlike our native madrone, or A. menziesii, strawberry trees are easily adaptable to ornamental landscapes, but be careful of overwatering, especially in heavy soils. There is another cultivar called A. unedo 'Elfin King' that is most assuredly a shrub and not a tree, because it only reaches 5' tall. This dwarf cultivar would be a great substitution for smaller spaces.
West Valley College Campus Location: Arbutus unedo 'Compacta'
Cilker (north garden)
Lat: 37°15'57.91"N
Long: 122° 0'40.64"W
facts
Botanical Name: Arbutus unedo 'Compacta'
Arbutus: Traditional Latin name for the species, Arbutus unedo.
Unedo: Edible fruit, derived from unum edo for "I eat one," implying that one might be enough due to their mild or uninteresting flavor, or only one is gratifying.
Compacta: Dense, compact
Common Name: Dwarf strawberry tree; compact strawberry tree
Family Name: Ericaceae
Origin: Southern Europe
design considerations
Positioning: Lawn (with good drainage), background
Garden Themes: Mediterranean/dry, coastal, kitchen
Uses: Edible, planter, border, accent, informal hedge, screen, focal point
identifying characteristics
Type: Evergreen shrub
Form: Round
Texture: Medium
Size: 10' tall and wide
Outstanding Feature(s): Flower, fruit
Bark: Red-brown, exfoliating
Leaf:
Type: Simple
Arrangement: Alternate
Shape: Oblanceolate, obovate
Margin: Serrate
Color: Medium green
Surface: Smooth, slightly glossy
Flower: Autumn into Winter. White, urn-shaped, small, in panicles. Showy.
Fruit: Autumn into Winter (approximately one year after bloom). Attractive, showy, round, highly textured fruit is bright green when young turning yellow, orange, then red when ripe. Flowers and fruit at all stages may be present at the same time. Edible (recipes online).
cultural requirements, tolerances & problems
Sunset Zones: 4-24
USDA Zones: 7-9
Light: Full sun to light shade
WUCOLS SF Bay Area Hydro Zone: Low
Soil:
Texture: Clay, loam, sand. Well-drained
Moisture Retention: Accepts brief periods of dryness.
pH: Slightly acidic to slightly alkaline
Tolerances: Heat, drought, pollution, coastal, lawn planting
Problems: Fruit drop may be messy
Branch Strength: Strong
Insects: Scale, thrips
Disease: Anthracnose, phytopthora, root rot, rust
cultural interests
The Strawberry Tree shows up in various historical accounts of Western culture. The ancient Greeks prized the wood for flute-making. In ancient Roman culture it is mentioned by Pliny the Elder and Ovid. In Italy the poet Giovanni Pascoli describes the tree as a symbol for the Italian flag because they both bear the colors of green, red and white. Its fruit was central to Hieronymus Bosch’s painting ‘Garden of Earthly Delights’. Madrid Spain’s coat of arms features the Arbutus and a bear (‘The Bear and the Strawberry Tree’ or ‘El Oso e El Madrono’). In Ireland there is an ancient folk ballad “My Love’s an Arbutus.”
~ As referenced by Catherine Nelson (2016)
citations & attributions
Gilman, E.F., Watson, D.G. (1993). "Arbutus unedo: Strawberry-tree." Department of Agriculture, Forest Service; Southern Group of State Foresters. Accessed on July 26, 2021, from https://hort.ifas.ufl.edu/database/documents/pdf/tree_fact_sheets/arbunea.pdf.
Nelson, C. (2016). "December 2016 Plant Profile: Arbutus unedo." University of Washington Botanic Gardens, Seattle. Accessed on July 26, 2021, from https://botanicgardens.uw.edu/about/blog/2016/11/26/december-2016-plant-profile-arbutus-unedo/.
Norris Brenzel, K. (Ed.). (2012). The New Sunset Western Garden Book. New York: Time Home Entertainment, Inc.
SelecTree. UFEI. "Arbutus unedo Tree Record." 1995-2021. Cal Poly State University, San Luis Obispo. Accessed on Jul 26, 2021, from https://selectree.calpoly.edu/tree-detail/177.
Water Use Classification of Landscape Species. "WUCOLS IV Plant List." University of California, Division of Agriculture and Natural Resources, Davis. Accessed on June 28, 2021.
Photos:
All photos by TELCS.