Quick Answer: Hilling, earthing up or ridging is the technique in agriculture and horticulture of heaping soil up around the base of a plant. It can be done by hand, 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, force the plant to grow longer stems, or for some crops this blanching technique keeps the stems or shoots pale and tender, or influences their taste. Hilling helps to smother weeds. It may also be used to stabilize the stems of crops which are easily disturbed by wind.