A bog garden is similar to a rain garden in that it holds water after a storm and allows it to slowly percolate into the ground. A bog garden, however, rarely dries out completely usually due to the high clay content of the soil. Filling the area with lush plants and flowers will keep the water shaded and disolved nutrient levels low. This will greatly reduce mosquito and algae problems. Sometimes you have a wet area in your yard that cannot drain anywhere. A good use for a bog garden is converting a patch of lawn that never dries out into an attractive plant oasis instead of a muddy mowing mess.