The Globe and Mail reports in its Wednesday edition that sales volumes of legal weed increased 8 per cent in July. The Globe's guest columnist Michael Armstrong writes that summer sales also demonstrated the importance of an expanding network of bricks-and-mortar retail stores. It is time for federal and provincial governments to review their pot strategies. July's strong growth was due to dry weed sales climbing 14 per cent to 11,387 kilograms. Both recreational and medical volumes increased. By comparison, cannabis oil volumes rose only 2 per cent to 9,854 litres and remained below its May peak. Recreational sales grew to 5,558 litres -- but that gain was largely negated by medical sales falling to 4,296 litres. July was the second month of this oil divergence, implying that many oil users were switching suppliers. It is possible some medical users prefer the physical stores and/or wider product selections that recreational vendors offer. CannTrust Holdings also contributed to the switch-over by halting sales in July. It had been serving 72,000 registered medical clients, about a fifth of the national total. Given a sudden need to find new suppliers, some likely shifted to the recreational market.