This is one of my favorite gardening tricks – and a great solution for that “where did I plant what” puzzlement you might experience when looking at your garden. Carrots (and spinach, and beets) take a long time to germinate, and I often lost sight of where I planted rows, especially when I’m working with long rows. Easy solution: just plant radish seeds. Radishes sprout within 3-4 days, so they make great row-markers!