Hilling, earthing up or ridging is the technique in agriculture and horticulture of piling soil up around the base of a plant. It can be done by hand (usually using a hoe), or with powered machinery, typically a tractor attachment. Hilling buries the normally above-ground part of the plant, promoting desired growth. This may encourage the development of additional tubers (as with potatoes), force the plant to grow longer stems (leeks), or for some crops (chicory, leeks, asparagus etc.) this blanching technique keeps the stems or shoots pale and tender, or influences their taste. Hilling may also be used to stabilize the stems of crops which are easily disturbed by wind.