Since Kew Gardens expanded its Mediterranean Garden about 15 years ago and created two new mounds criss-crossed with rocky paths between ancient olive trees, cypresses, lavender and cistus, I have been intrigued by another of the trees planted there, the cork oak, Quercus suber. What a tree! Every few years it is stripped of its unique corky bark, which gradually regenerates, only to have it peeled off again several years later: sustainability in action! The cork production industry is vital to the economies of rural communities in Portugal and south west Spain as well as parts of North Africa, southern France and Italy.
One of the most memorable interpretation displays I have seen in any museum (and Royal Botanic Gardens, Kew is a museum, it’s just that its collection is living), was erected in the Mediterranean Garden to demonstrate the threat to the cork industry of the introduction of synthetic wine bottle stoppers made from plastic and metal. Visitors were invited to return with their used wine bottle tops and deposit them in one of three clear-fronted compartments to demonstrate which of the three methods of sealing wine bottles was most commonly used. This citizen science project proved surprisingly popular and the containers gradually filled over the course of the summer. I seem to remember that the natural corks container always appeared the fullest but I haven’t been able to find the official outcome of the experiment. It certainly drove home the message that far from plundering a natural product, choosing wine in bottles with natural corks supports a sustainable way of life.
A fortnight ago I was lucky enough to visit the beautiful area to the north west of Seville known as the Sierra de Aracena. Wooded hillsides protect quiet villages, the forests of cork and holm oaks providing rich foraging for the Cerdo Ibérico (popularly known as the Pata Negra), the black-footed pigs from which the region’s famous Jamón Ibérico is produced. The friend I travelled with lives in the New Forest and commented that it reminded her of the pigs which each autumn are allowed to roam freely in the forest snuffling for acorns, beechmast and chestnuts under the ancient tradition of ‘pannage’.
Our base for three days’ walking was a small hotel, the Posada San Marcos, in the pretty village of Alájar.
The 18th century house on the edge of the village was restored about eight years ago, using sustainable building materials including cork. With fire-proof and damp repellent qualities, cork is apparently often used as an insulating material and has the benefit of conserving heat and acting as a sound-proofing barrier.
The hotel’s garden ran down to a river, beyond which rose a steep hillside densely planted with cork oaks with smooth trunks to about three or four metres.
Undeterred by heavy rain on the first day’s walk, we followed a path through the forest towards a neighbouring village, Linares. Narrow and rocky, the path was reduced by the rain to a small stream in places bounded on either side by moss and fern covered stone walls beyond which grew the cork oaks.
Slick with rain, the lower trunks of the cork oaks resembled dark chocolate riven here and there by reddish gashes, with what resembled long sleeves of gnarly cork encasing the upper trunks and limbs.
It was clear that the junction between the two surfaces was created by man, given the neatness of the margin between the flayed trunk and the lichen encrusted cork. The weather was fine and dry during our second and third days’ walking and I could see that when dry, the more recently stripped cork oak trunks are a beautiful reddish brown. I understand that the cork outer bark can be peeled away once the tree reaches 25 years of age, and the tree can then be stripped every nine to ten years without damage.
We stayed in Seville at the end of our trip and came across a chain of shops selling accessories made from thinly cut cork: handbags, fans, watch straps and jewellery. Very pretty but a far cry from the coarse surfaces of the trees 80k away in the shady forests of the Aracena. My favourite cork object were the rough-hewn (and very light) stools and bowls we found in a the small town of Fuenteheridos where we stopped for lunch during one of our walks.
When I returned to Osterley on the Friday after my holiday I went to see the Osterley Park Cork Oak, an impressive 250 year old specimen located beside the Middle Lake and protected with a metal railing barrier. It is designated as one of the ‘Great Trees of London’. Whilst the climate of west London cannot rival the hot and generally (!) dry conditions in the western Mediterranean, Osterley’s cork oak is thriving. As an ornamental it has not been shorn of its cork carapace and its trunk remains gloriously gnarled. With this and the specimens planted at Kew, it’s comforting to know that examples of this fascinating tree exist close to home, no passport required.