Potash is especially important for the root crops, as beets, carrots, turnips, radishes and parsnips. It also enters largely into the composition of many other vegetables. Applications are particularly important for sandy soils and for muck lands.

Muriate of potash is the most common form used by vegetable growers; but sulphate of potash is preferred for potatoes, and kainit is used sometimes by asparagus growers.