Problems transplanting ferns?

im new at gardening.. my mom has a ton of ferns growing in her yard. i have tried to dig some up and transplant them in my yard. everytime i do this they wilt and die off. i have tried putting them in different spots. shaded spots and areas that get little sun. no luck. i have tried adding better dirt like the miracle grow stuff. no luck. any suggestions or what am i doing wrong?