In 1977 and 1978, plants of the strawberry cv. Cambridge Favourite were grown in identical outdoor bins (3.6 m long, 1.8 m wide and 0.3 m deep) at Invergowrie and Auchincruive, in the east and west of Scotland, respectively. In each year, compost from the same mixing and plants from the same source were used at both sites. Runner production varied from 2 to 4.5 times that usually achieved in commerce. This increase in productivity probably resulted from the improved growing conditions provided by the bins. Although the total number of runner-plants produced was the same at both sites, more large runners and fewer small unplantable runners were lifted at Auchincruive than at Invergowrie. The warmer growing season in the west compared with the east was considered to be the cause of this difference.