Whаt dоes the cоllоcаtion ‘growing seаson’ mean in Paragraph 4? 4. A recent study published in The Lancet analyzed the length of pollen season and the amount of pollen per plant in 17 locations across the northern hemisphere. According to the data, which was collected over 26 years, 70% of the locations saw increases in the total amount of circulating pollen per growing season. In 65% of the spots, the pollen season got longer due to an "ongoing increase in temperature extremes," the authors reported