Unusually heavy rains drenched northern swathes of China in September and early this month, flooding the top vegetable-growing province of Shandong. The rise, at a time of growing scrutiny for inflation, is worrying government officials in Beijing who are keen to ensure sufficient food supplies ahead of winter. "Our natural gas prices are up at least 100% and we think they could triple during Chinese New Year," said Xu Dan, manager of the HortiPolaris greenhouse in Beijing, referring to China's most important holiday, due next February.