In the year after a flood, new weed problems will be likely. Mechanical and chemical methods need to be considered in both the flood year and subsequent years to manage weeds. A bioassay test in which seeds are planted in flooded and non-flooded soil samples can be helpful to determine if soils are safe for intended crops. If the crop recovers after the flood, make an effort to reduce the impact of weed competition. This may not be practical if fields are too wet to enter for mechanical or chemical weeding.
Check fields regularly to monitor crop and weed development.
Take note of weed species. This may happen if weed seeds were carried into the field by floodwater. Make a field map of these weed locations and use it to plan next year's weed management program. Consider whether herbicides can be safely applied. Most labels clearly specify the maximum growth stage of the crop at which the product can be used.