Soil Conditions and Vegetable Storage

Excessive moisture in the soil before harvest can influence the storage life of some vegetables. Among crops most likely to be influenced are potatoes, onions, winter squash, pumpkins and sweet potatoes. Wet weather before harvest can influence crops in two ways that may lead to reduced storage life. The tissue of the crop may be higher in water content. Also, fungus diseases present are more easily spread by heavy rains and can infect plants more easily when they are wet for longer periods.

These conditions may work together since vegetables with a higher water content than normal are more easily bruised during harvest. Bruised tissue is more easily infected and consequently rots faster. Abrupt heavy rains after dry periods can also lead to cracking, which could be another source of infection. To get the longest storage life from these or other vegetable crops harvest carefully to avoid bruising or scraping; provide proper conditions for pre-storage hardening and drying; and provide the best storage conditions possible in your home.

If you have a storage area that you use yearly, it is possible that diseases are already present from past storage. Therefore, thorough clean-up is important before placing a new crop in storage. Wash storage boxes, baskets or shelves with a solution of one part chlorine bleach in nine parts of water along with a household detergent. Before storage many vegetables will benefit from a curing period. During this period vegetables should be spread out or placed where they get good air circulation around them.

Potatoes should be cured at temperatures close to 60 or 65 degrees for two weeks before putting in final storage. This allows the skin to toughen and any scratches or cuts to heal over. Before finally placing them in cool, humid storage, check them carefully to remove any that have started to rot or have not healed over because of deep wounds. Onions should also be cured at warm temperatures with good air circulation for about three weeks before placing in mesh bags or open crates for final storage.

While potatoes need cool storage with high humidity, onions need cool storage with low humidity. Pumpkins and winter squash should have hard rinds and good color when harvested. After harvest they should be kept very warm (about 80 degrees F.) for about 10 days. During this time any wounds should heal. Stems should not be removed since the open end where the stem was attached is easily infected by disease causing rots. Best final storage temperature for these crops is 55 degrees F.

Sweet potatoes should not be harvested until near frost since they should still be growing. They are easily bruised during digging, and therefore also need to be cured before final storage. About one week at 80 to 85 degrees F. should allow enough healing to occur. After that time they should be kept at about 55 degrees at a fairly high relative humidity.