Answer: You didn't mention whether the site is sunny or shady so I've included recommendations for both types of sites. These plants have fibrous roots which will help knit the soil together to keep it from eroding:
Lily of the valley; Sweet Woodruff; Wild Ginger; Red Barrenwort; Periwinkle;
Convolaria Majalis; Galium Odoratum; Asarum Europaeum; Epimedium X Rubrum;
Sedum; Snow in Summer; Moss Pink; Thyme; Lamium; Chamomile; Sedum Spurium; Cerastium Tomentosum; Phlox Subulata; Thymus Serphyllum; Lamium Maculatum.
Best wishes with your landscape!
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