winter protection, cumbersome viticultural technique aimed at protecting vines in cold, continental climates against the effects of winter freeze. Vines are buried in autumn to benefit from the fact that winter temperatures below the soil surface are never more than a few °C below freezing point, whereas the air temperature can be more than 20 °C/36 °F colder. Burying vines is, however, labour-intensive and expensive. This was traditionally practised in central Europe and North America, but is uncommon now because of the cost. Only in the vineyards of russia, parts of ukraine, some of the central Asian republics, and china is it still considered an acceptable price to pay for viticulture, although some severe winters in upper new york state in the early 21st century have engendered some reconsideration. The procedure has been modified so that just those few canes to be used for fruiting the following year are buried. Vines are also trained so that they have several trunks, so that those killed in winter can easily be replaced. See fan-shaped training systems.