Grass growing under trees or along a shaded fence line often thins out no matter how much care it receives, because it simply is not getting enough light to compete with the rest of the lawn. Moss, on the other hand, thrives in exactly these damp, shady conditions where grass struggles most.
Rather than fighting to keep grass alive in a spot it clearly dislikes, allowing moss to take over that particular patch often produces a far better result with much less effort. It stays green through most of the year and needs no mowing at all once it becomes established.
A different texture, not a failure
A mossy patch has its own soft, dense texture that many people come to prefer once they stop viewing it as a problem to be fixed. Bare feet notice the difference immediately, and the contrast with the surrounding lawn can even become a deliberate, attractive feature rather than an eyesore.
Moss also supports its own small community of insects and other creatures that rarely visit a closely mown lawn. This quiet corner can become one of the more interesting parts of the garden simply by being left to develop in its own way, without constant interference.
Accepting a shady, mossy patch rather than repeatedly reseeding it saves time, money and a fair amount of frustration each year. Once the switch in mindset happens, many gardeners find they actually prefer the look and feel of moss to the patchy grass that used to struggle there before.
A mossy patch also copes far better with dry spells than thin, struggling grass does, since it simply pauses its growth and greens up again once damper weather returns. This resilience makes it a genuinely practical choice for a corner that has always been difficult to keep looking tidy.
Edging the mossy area neatly with a simple border of stones or timber can help it read as a deliberate feature rather than a neglected patch, especially to visitors who might otherwise assume the lawn has simply been left unattended in that one particular corner of the garden.