Urban gardener, Cleve West: The world's first urban garden?

A brief but utterly absorbing foray in a bustling souk to root out the Egyptian equivalent of the Urban Gardener soon had us searching for an oasis as if our lives depended on it. The naïve decision to engage directly with anyone even glancing in our direction had backfired alarmingly when the manhandling tactics of a persistent trader sent us scurrying deep into a labyrinth of narrow streets. Rich hues, smoke and an irrepressible conflict of aromas did their best to seduce us but my partner, Christine, and I felt even more conspicuous and we shrank sheepishly from the cacophony, like day lilies at sunset, back to the relative sterility and comfort of our ship The Saga Rose.

I'd come to share the joys of an allotment and memories of this year's Chelsea Flower Show with Saga folk, while enjoying the ancient sites of the Mediterranean. Jekka McVicar was there too to talk about herbs, and as the lights of Alexandria vanished from the horizon, our minds turned to Benghazi, our next port of call in the Great Socialist People's Libyan Arab Jamahiriya.

With tourism still a relatively new concept in Libya, our souk experience there was, by comparison, a walk in the park, with people both charming and retiring. But my quest to discover something to report took a back seat until we reached the ancient site of Ptolemais.

The litter-choked no-man's land skirting Benghazi reluctantly gives way to ploughed fields and scrub where the hills of Al Jabal al Akhdar (The Green Mountain) that stretch southwards to the Sahara Desert provide a convenient barrier to the onslaught of the desert beyond. The land here, trapped between the hills and the sea was once, according to our guide, rich and fertile enough for a wide variety of fruit and vegetables but had suffered under Gaddafi's rule and now produced token wheat and barley crops, and grazing for goats.

The site of Ptolemais, despite being some two-and-a-half times bigger than Pompei, is unassuming at the entrance where a modest museum and restaurant face a small dusty courtyard with scattered treasures of sarcophagi, statues and, most valued of all, dense shade of Eucalyptus. The unforeseen trade-off for introducing this non-native (so prevalent now in the Mediterranean one could be forgiven for thinking them indigenous) for shade and stabilisation of sand dunes has been a reduced water table in some desert regions.

It's only after some five minutes' walking that the Cyrenian city come into focus. Axis and avenues, fractured walls, columns and baths furnished our imaginations while the dexterity of biblical goats deftly grazing scant foliage among thorns of acacias was captivating. With Jekka searching for herbs to back up research for a new book, I pondered the modest spaces of gardens adjacent to the Palace of Columns, a luxury dwelling in the heart of the city. The city, founded during the 3rd century BC, provides evidence of one of the earliest urban gardens. Not much bigger than a small town garden in London, seclusion, shade and fountains would have made it a priceless sanctuary from the bustle of the city and the intense heat of summer.

The earthquake that caused huge damage to the city AD365 means there is still much to unearth, but the giant subterranean cisterns that once stored almost five-and-a-half million cubic metres of water are still largely intact. These would have kept the city alive and may well have been used to irrigate crops, but the land would also have yielded drought-tolerant herbs for medicine, food and cosmetics, much as they do today. Jekka, in her element, snapped away at wild thyme, silybum and phlomis while I took curious satisfaction a-spying what looked like a type of eremurus (they'll make a plant hunter out of me yet). It turned out to be Giant Sea Squill ( Urignea maritime), a large, poisonous bulb that has been used by herbalists since Dioscoardies, a Greek physician, found it effective in treating heart and respiratory ailments. A red variety was also used by Bedouin to kill rats. The ancient urban garden was indeed a luxurious bounty.