Radishes (Raphanus sativus) are among the fastest crops in the garden: in spring and autumn they are ready three to five weeks after sowing, which makes them ideal for beginners, children and gaps between slower vegetables. Sow directly outdoors from March, 1 cm deep and about 3 cm apart, and repeat every two weeks for a continuous supply. They grow best in light, loose soil that is not freshly manured, in sun or light shade. The secret of mild, crisp radishes is even moisture: when the soil dries out, the roots turn woody, hollow and hot. In long summer days and heat they tend to bolt without forming a proper root, so pause sowing in July or use summer-tolerant varieties, then resume in August for an autumn crop. Flea beetles riddle the leaves with small holes in dry weather; fine mesh and regular watering help. Pull radishes as soon as they reach full size – left in the ground, they turn spongy within days.