FOR PETER GLAZEBROOK, THERE WAS one bright spot to 2020. A leek he entered into last year’s Mansfield Grow Show, which judges declared to be a monstrous four feet long, won him a new world record. “That makes 16 world records I’ve held over the years,” Glazebrook wrote to me recently, via email. “However, it’s a competitive hobby, so I currently only hold three.” Today, he is the proud grower of the world’s heaviest cauliflower (60 pounds), potato (10 pounds), and, as of 2020, the longest leek. Glazebrook, a lithe, 76-year-old former building surveyor from Nottinghamshire, England, is one of...