Dahlia season is at its peak in Martha’s garden.Credit: romrodinka / Getty ImagesIf there’s one flower that we can always guess will make a reappearance in Martha Stewart’s garden, it’s the dahlia. In fact, Stewart is even said to have helped make the dahlia as popular as it is today, thanks to her use of them in the wedding industry. Now, dahlias of all shapes, sizes, and colors take up part of Stewart’s Bedford estate each year. In Stewart’s g…