Myths, Moss and Mushrooms
It's is a common belief that moss growth is due to soil acidity and that the addition of limestone will improve the soil and kill the moss. Though pH does have some bearing on moss development, it is not the limiting factor. It is not too likely that an arbitrary application of limestone will effect the moss, and too much lime can have a negative effect by impeding nutrient movement in the soil.
Moss growth will prevail in areas where excess shade and moisture are present, and where poor soil quality impedes drainage and nutrient uptake. If the soil looks good, do what you can do dry out the area. Limit irrigation and prune overhanging limbs to provide at least three hours of sunshine each day.
If the soil is thin and compacted or contains a high percentage of peat or humus, the addition of fresh soil may be necessary. Physically removing the moss is not usually difficult. Once done, the area can be top dressed with fresh loam and re-seeded. By controlling the shade and moisture on your new seedbed you will be able to reclaim your lawn from moss encroachment.
Mushroom development is a cause of concern for many customers. Though mushrooms are a fungus, treating the lawn with fungicide will not provide an effective control. Mushrooms develop on decaying woody matter. A buried stump or wood chips and twigs within the soil will provide an excellent location for mushroom colonization. If excavating the problem area is out of the question, picking and disposing of the mushrooms is the best defense.
Mushrooms propagate through the spread of spores. Mowing or otherwise disturbing the mushroom cap can spread spores and aggravate the problem. To reduce the number of mushrooms in a lawn area, gently pick and place the mushrooms in a bag for disposal. You will have to repeat the process a few times before eliminating the problem. Good luck and be careful not to step on any Leprechauns!