Flooding: Before & After
Restoring Vital Services — Care of flooded vegetable gardens
There is little that can be done to save a vegetable garden that has been flooded. Whether or not the plants survive and live will depend to a large extent on how long the garden remained flooded. Most vegetables cannot tolerate standing water for any length of time.
If possible, provide some means of draining any excess water from the garden immediately after flooding. This means digging ditches or furrows that will allow water to drain away from the garden.
As soon as the soil dries enough, work the ground to break away any crust that may have formed. Try to wash away any soil film that has settled on the leaves of the plants. You should know within a week if the plants are going to live. If they do survive, you will probably need to spray fungicides and insecticides to control diseases and insects. It will probably be necessary to side-dress most crops with nitrogen since floodwaters probably leached much of the original application of nitrogen away.