Ever since King Carlo III of Naples started excavations in 1748, thousands of studies have been made of the lost city of Pompeii, but the site still comes up with surprises. For the last ten years, a laboratory of applied research an offshoot of the superintendent in Pompeiis department of archaeology has been researching a hitherto little-known aspect of 1st century AD town life. The results have been set out in a fascinating exhibition entitled: De Gustibus from the Vegetable Garden to the Table, at present on show inside the ruins of Pompeii.

The laboratory, headed by Anna Maria Ciarallo, has just completed a census of Pompeiis orchards and vegetable gardens. There were a total of 402 inside the city walls, she says. Previously, it was thought that slaves went outside to work in the fields, but now we know that they also worked on cultivated land within the city. Some of these plots were quite small and probably served private households.

Most of the agricultural areas are grouped at the eastern end of the excavations, near the amphitheatre and the large palestra, or outdoor gymnasium, at the opposite end of Via dellAbbondanza from the main entrance at the Porta Marina gate.

The exhibition has been set up as an itinerary leading visitors through a series of vegetable gardens, vineyards and orchards that the laboratory has lovingly restored and replanted as they originally were before the fatal eruption of 79 AD.

Pompeii offers a unique opportunity for this kind of research because the volcanic explosion preserved furrows, plant roots, seeds and pollen, Ciarallo explains. We can therefore be sure of making a reconstruction that is 99 per cent accurate. We know how the plots were laid out and that some had their own wells and others got water from the town aqueduct.

One of the surprises revealed was traces of lemon trees, thus scotching the common belief that lemons were introduced from Arab countries only in the Middle Ages. Another was the profusion of vineyards.

Grapevines were by far the most common type of cultivation, says Ciarallo with a smile. At first, I asked myself why. Of course, tradition has always claimed that the people of Pompeii were great consumers of wine, but when we went more deeply into the matter we found that wine had many uses. Essences of wine were the basis of many medicines and a lot of food was preserved in vinegar. Maybe there wasnt all that much left over just for drinking.

The De Gustibus tour begins at the Thermopolium one of the many ancient snack bars that were dotted around the city, where visitors can purchase products based on ancient Pompeiian recipes and herbal treatments, including sachets of herbs and oriental spices and typical oils and essences used as beauty aids. To show how much eating habits can change, a bed has been planted out along one wall with plants like nettles, old mans beard, butchers broom and field marigolds, which are now considered weeds, but which the ancient Romans grew as edible crops.

In the kitchen, they used native herbs that we use very little nowadays, such as dill, cumin, sweet marjoram, coriander and mastic seeds. They also had spices from the Orient such as ginger, cinnamon, cloves and various kinds of pepper, Ciarallo says. Preserving foodstuffs for the winter was also very important. Apples, figs, olives, dates and grapes were all dried and preserved.

The next stop is the house of Octavius Quartio, commonly known as the Villa of Loreio Tiburtino; he was a well-off Pompeiian citizen with a splendid triclinium, or dining room, overlooking a landscaped garden with grapevine bowers, ponds and an orchard of almond, olive, pear, quince, pomegranate and cherry trees.

These were the home-grown fruit most commonly consumed at the table, Ciarallo explains, as she conducts us past the orchard of Giulia Felice, which has also been replanted. Other fruit such as peaches, that we eat nowadays, were used as medicines, and so were lemons, rosemary and sage.

The House of Venus, a little further down Via dellAbbondanza, is interesting because the garden was dedicated to the cultivation of plants that were sacred to the goddess of love. Roses, myrtle and pansies (the latter in place of the more ephemeral violets) are now blooming in front of the frescoed wall of Venus reclining placidly on her seashell.

Special attention has been given to grape-growing. Outside the walls, Mastroberardino, a noted Campania wine-producer, has set up a series of trellises in the fields to illustrate the various systems that were used to support the vines. The same company is also conducting an interesting experiment in one of the towns walled vineyards, where it has planted ten native Campania grapes to see which one adapts best to the area and the climate.

The last garden on the list is attached to a perfume-makers house, where the costly scents much favoured by women of ancient Rome were produced. The large garden is full of the flowers and shrubs commonly used in the perfumiers trade. Essences of roses, lilies, myrtle, violets, hyacinths and irises were mixed with the juice of unripe olives. Other ingredients included herbs that we now generally use for cooking, such as dill, basil and thyme.

The exhibition can be seen as part of a visit to the excavations, where it adds a new and vivid dimension to the scene of the tragic eruption.

The De Gustibus exhibition is open until 26 June. Entrance Piazza Anfiteatro. Full-day ticket (including all Pompeii excavation): 10, reduced 5. 08.30-19.30 (ticket office closes at 18.00). Combined ticket for Pompeii, Herculaneum, Oplontis, Stabia and Boscoreale: 18, valid 3 days.

For information tel. 0818575347 or see www.pompeiisites.org.