This will cause the leaves to go a yellow or brown color and they will usually drop off.
When plants start getting waterlogged the leaves at the bottom of the plant will be affected first.
By the time the upper leaves of the plant start turning yellow and brown you have a real problem.
The problem arises because of the fact that plants need air as well as water around their roots to survive and with excessive watering the air pockets in the soil are filled with water.
Without this air the roots of the plant will begin to die and as the roots are needed to supply the plant with the necessary nutrients to survive, the plant begins to die from the bottom up.
That is why you see the lower leaves getting affected first.
To remedy the situation you will need to allow the soil to dry out to reduce the water content.
If the plant is in a container you will need to check to see whether there are sufficient drainage holes to allow excess water to escape.
If the soil has become compacted from all the water it is best to remove the plant and give it some new soil.
Often when plants begin to wilt they can appear to be lacking water when the opposite is the case so it is best to check the moisture content of the soil before assuming the plant needs more water.
When watering the plants allow the soil to dry out completely, or partially between watering to reduce the chance of them getting waterlogged.
Try to improve the drainage of the soil for plants in the garden and even consider raising the garden for better water control.
