Earthing-Up: Earthing up simply draws up the soil around the plants.  Potatoes are earthed up to prevent tubers turning green and inedible with the toxin solanine.

Earthing-up also helps protect them against blight.

It helps protect against frost damage.  Newly emerged foliage can be protected by earthing-up the soil around the shoots.

When young stems are about 9 inches high (23 cm), start drawing soil up to the stems and covering to produce a flat-topped ridge about 6 inches high (15 cm).  Preferably this is done in stages, little and often.

Other Crops 

Earthing up can also be beneficial to brassica like Brussels sprouts, which can be top-heavy and have to survive the winds of autumn.

  • leeks, celery and Florence fennel are earthed-up to blanch the developing stems or bulbs.