Moss in a lawn or garden bed doesn't harm the plants, but it does indicate less than ideal conditions for growing lawns or plants. Moss prospers in cool, moist soils that lack lots of nutrients.
According to Oregon State University, spraying herbicides with the active chemical ingredient glyphosate, in most situations, fails to fully kill moss. Burning or yellowing of moss scales may occur, but the moss endures and its spores continue to germinate.
Change the environmental conditions to get rid of moss. Increase light and air circulation to help soil dry out after rains or improve site drainage. Fertilise in nutrient-poor soils to encourage other plants to grow and shade or choke out moss populations.
Products containing nitrogen, iron or copper tend to kill moss more effectively, according to Oregon State University. Look for products containing copper sulphate, iron sulphate, ferrous ammonium sulphate or fertilisers rich in nitrogen.