Why didn't my spot treatments control the moss?

Spot treatments of moss control products are frequently the most effective and economical way to beat back infestations. But every once in a while, we hear of situations where spot treatments failed to do the trick. The question is, why?

The answer in most cases is that you really need telescopic vision to find early signs of moss infestation. Most people miss these little bundles of joy, and as a result, these small, nearly invisible patches are now free to…