granary. When softened by boiling it is good fodder for cattle during the winter; in the case of humans, too, it serves to warn off famine if years of crop failures come upon them. Olives The Romans grew olive trees in poor, rocky soils, and often in areas with sparse precipitation. The tree is sensitive to freezing temperatures and intolerant of the colder weather of northern Europe and high, cooler elevations. The olive was grown mostly near the Mediterranean Sea. The consumption of olive oil provided about 12 percent of the calories and about 80 percent of necessary fats in the diet of the average Roman. Grapes Viticulture was probably brought to southern Italy and Sicily by Greek colonists, but the Phoenicians of Carthage in northern Africa gave the Romans much of their knowledge of growing grapes and making wine. By 160 BC, the cultivation of grapes on large estates using slave labor was common in Italy and wine was becoming a universal drink in the Roman empire. To protect their wine industry, the Romans attempted to prohibit the cultivation of grapes outside Italy, but by the 1st century AD, provinces such as Spain and Gaul (modern-day France) were exporting wine to Italy. Fodder Columella mentions turnips as important, high-yielding food crop, especially in Gaul where they were used as winter fodder for cattle. As other "fodder crops" he lists Medic clover, vetch, barley, cytisus, oats, chickpea and fenugreek. Of Medic clover, he says it improves the soil, fattens lean cattle and is a high-yielding fodder crop. Cato the Elder wrote that leaves from poplar, elm and oak leaves should be gathered in the Fall before they have dried completely and stored for use as fodder. Turnips, lupines and forage crops were to be sown after the rainy season. Other crops The Romans also grew artichoke, mustard, coriander, rocket, chives, leeks, celery, basil, parsnip, mint, rue, thyme 'from overseas', beets, poppy, dill, asparagus, radish, cucumber, gourd, fennel, capers, onions, saffron, parsley, marjoram, cabbage, lettuce, cumin, garlic, figs, 'Armenian' apricots, plums, mulberries, and peaches. Storage Columella describes how produce is stored and gives advice to prevent spoilage. Liquids produced for market like oil and wine were stored on the ground floor and grain was stored in lofts with hay and other fodder. He instructs that granaries be well ventilated, cool, with minimal humidity, to prolong freshness. He describes certain methods of