The answer to 'flower bed erosion' is that it is a common problem caused by heavy rain, runoff, or poor soil drainage. Symptoms include soil washing away, plants leaning or dying, and exposed roots. Solutions can include adding mulch, planting ground cover, building retaining walls, or improving drainage.
If the erosion is severe or you're unsure of the cause, it's best to consult a professional landscaper. They can assess the issue and recommend the best long-term solution, whether that's DIY fixes or more extensive landscaping work.