Arbutus unedo f. RUBRA strawberry tree
Arbutus
I am a great admirer of the Mediterranean macchia. This term refers to a unique type of predominantly evergreen broadleaf vegetation found in the arid and often rocky landscapes of southern Europe. It includes species such as osmanthus, strawberry tree, holm oak, rosemary, broom, Phillyrea, and many others. These plants have developed a defensive arsenal against extreme drought (thick, leathery leaves serving as water reservoirs), heat (glossy foliage reflecting sunlight), and grazing animals (spines or repellent aromatic oils), which has enabled them to survive in very inhospitable places.
We have also discovered that this resilience somehow translates into their frost hardiness, too, so we began testing them one by one. Today we already have an entire group of Mediterranean plants that are thriving increasingly well here in zone 6, since with the changing climate the soil is losing water and these shrubs and small trees are not only accustomed to drought – they actually require it. Moreover, they are evergreen, which is an important advantage for our long winters.
Strawberry tree is another of my favourite evergreen plant, formerly classified as tender in C.E. continental climate, but we began a long-running trial where we test a group of Mediterranean plants for their hardiness. It started when we noticed that many macchia plants have to struggle with adverse conditions almost on daily basis such as less and less water year after year. The climate is changing and macchia plants both show their assets and do their best to adapt. The surprising, yet in the end understandable moment was that their resilience and ability to survive is also reflecting in their hardiness. This makes them exceptionally suited for milder parts of our climate (Central Europe) because along with resistance to drought, wind, heat, and poor soil they seem to benefit from current lack of water in the ground whose excess had always been a killer for tender plants. Therefore, some of these drought-tolerant macchia plants make a whole new group of desirable species even here. Arbutus unedo is one of them and we continue testing more and more varieties as they become available from breeders. So far, all of them we have trialed performed a miracle!
Rubra is a common name for all forms of strawberry tree with red flowers. Only those plants which also boast other distinct features were selected and registered as individual varieties. It makes evergreen, narrowly oval to obovate, 6-10 cm long, leathery leaves with serrated margins, more conspicuous closer to the tip. They are medium to dark green and glossy. The twigs are orange, reddish when young, and as the bark ages it becomes shredding and changes to a pastel mahogany color, peeling off in small flakes.
The flowers are urn-shaped, raspberry pink to rosy red, and composed in pendent racemes. They make a splendid show opening in autumn when almost nothing else blooms. Depending on weather and climate type, flowers may continue blooming until late spring, and sporadically throughout summer, too. Meanwhile mature small, spherical, and edible fruit which is bright red when mature hence the name strawberry tree. It contains as much as 20% of sugars but the taste is rather dull, so it is mostly used in preserves and liquors.
Strawberry tree grows moderately into an upright and slightly spreading shrub with a domed canopy. I saw beautiful specimen plants trained into small multi-stemmed trees which reveal their attractive bark. To do so, select 3-5 main branches as a strong framework, remove all laterals until the top and clip its canopy into a mushroom head every summer. Thus, you can achieve a beautiful Mediterranean-style jewel. In its natural habitat it can grow 8 m tall or even more, however, in C.E. climate it makes about half of that.
Being from the heather family (Ericaceae) one would expect it would demand the same conditions as for example rhododendron. Not exactly. It needs extremely well-drained, humus rich soil in full sun or only light shade. Slightly acidic soil enhances the depth of green colour in leaves but is not essential. Always avoid compacted or water-logged ground where the roots may rot. It will need even moisture after transplanting but once established stay away from watering. We have not been able to observe its hardiness under all possible conditions but so far it has withstood -17 °C here which makes it suitable for at least USDA 7 without any protection. However, North American growers plant it up north to zone 6 claiming it can withstand -23°C without damage. Choose older plants for growing in zone 6 and provide good mulch for winter. It is disease free and as far as pests vine weevil attacks it rarely.
Last update 28-02-2024
