After the vegetables are received at the packing house several operations are necessary before they can be ready for packing. Many different classes of vegetables, as beets, carrots and other root crops, are washed to remove any soil that adheres. Water is used mainly for the sake of cleanliness, but it has other values which deserve consideration. It gives many vegetables a fresh, bright appearance and prevents them from becoming wilted and withered before reaching the market. Plumpness is also maintained, as is the case when the green pods of peas and beans are immersed in water for a few moments before packing for local markets. Thorough washing is generally regarded as necessary for celery, lettuce, asparagus and all of the root crops, and considered an advantage under certain conditions for many other crops. Whatever the vegetable, it must be clean to make a favorable impression on the buyer, although it is not always advisable to use water freely. Tomatoes, cucumbers, watermelons, muskmelons, squashes, peppers and eggplants can usually be wiped with a damp cloth to secure the required cleanliness.
Vegetables which are bunched may be washed before tying, but the most common practice is to wash after tying, because the work can then be done more rapidly. The bunches are thrown into a tank of water and washed; a brush is used if necessary. When the vegetables are not too much soiled, the use of the hose may be sufficient. Bunches of vegetables, like asparagus, celery and rhubarb, are often placed on end in washing tanks and water applied with considerable force from the hose, but scrubbing is also necessary sometimes.
Certain vegetables require trimming, stemming or shelling before packing.