Cabbage, Brussels Sprouts & Broccoli

The cabbage family is a common group of superhydrophobic plants. It is easy to see the effect when washing broccoli or cabbage leaves. The hydrophobicity can be a problem if the plants become diseased or attacked by insects, as sprays can bounce off just as water does. The addition of a little surfactant to the spray (usually present in commercial formulations) prevents this. The cabbage superhydrophobicity is caused by wax towers on its surface, as can be seen in the electron microscope picture on the right. This is a quite different structure to that of the Lotus, which looks more like a collection of hillocks, but is produced in the same way. Cabbage is very accessible, and is used in this demonstration of superhydrophobicity by the Science Museum of Minnesota.