Not necessarily but then there many different things people lump under the label "moss" so it would depend on which of those it actually is. But most mosses prefer less than ideal conditions for a garden to thrive - things like overly wet soil that drains poorly, excess run-off, compacted soil area, heavy shade, excess nitrogen, etc.

So its presence in a garden is more of an indication of potential problems than any real threat to anything.

Dave

Or a lovely, calming setting.

If the moist conditions allowing moss to grow are from your frequent watering or recent frequent rains then it should be okay. If the moist conditions are like digdirt2 said, a low area where the water in pooling and not draining, it could be the "bathtub effect" of having a garden bed in clay soil or in a poor draining area. This is bad and will lead to root rot. The solution is to use a raised bed or create some additional draining capability. I wouldn't do anything yet. Wait and see how the plants do and if hot dry weather dries out the bed more quickly.