Why do the surfaces of cabbage leaves repel water so superbly?
• Most leaves are coated in water-repellent waxes, which form a smooth cuticle. The super-repellent surface of cabbage leaves, however, has an extra powdering of flaky wax. When a droplet of water lands on this rough surface, it touches only the tips of the flakes. On a smooth cuticle, surface tension pulls the water over the surface, spreading it out, but this does not happen on the flaky wax because of the lack of contact with the surface. Instead, the water beads up and runs off the leaf. Other rough surfaces, such as leaves with fine hairs, have the same effect. An additional side effect of rough wax surfaces is that they scatter light more effectively – this is the source of the bluish-white sheen to your cabbage leaves. For a simple proof that it is the texture and not the chemistry of the wax that counts, smooth down a portion of the cabbage leaf with your thumb and then see how water behaves on this surface. Although cabbages are crop plants, the water-repellent effect is well
