Radishes are annual vegetables that are members of the Brassicaceae or Cruciferous family, along with broccoli, cabbage, cauliflower, kale, and collards They are started from seed in spring (for a spring harvest) or late summer (for a fall harvest) Some of the smaller radishes mature in as few as 25 days and the larger winter radishes can keep you waiting for up to 60 days Radishes, like most vegetables grown for their roots, are direct seeded in the garden Radishes grow quickly, they can be squeezed in between other plants in the vegetable garden Radishes are good for loosening and cultivating the soil for slower-to-sprout vegetables, like carrots