Question
I successfully germinated a DODECATHEON mix (which includes
D. meadia, meadia alba, amethystinum and pulchellum) this
spring.Tiny plants are now dormant and I plan to winter them
by sinking the pot in a plunge bed. Upon examination I
notice that roots are exposed and seem to be on the surface.
Should these be covered and if so with what, sand?
vermiculite? or? I garden in Merrill WI ~ z 4.
Thanks for your help.  

Answer
When roots are on the surface, it is usually an indication of shallow watering. That is why I always water newly germinated plants from the bottom. This encourages the plant to send its roots down, where it can benefit most from the nutrients in the soil.

Any potting medium will work fine to cover the exposed roots. I would definitely opt for the vermiculite, but a light sprinkling of a good potting soil will also be acceptable.

I hope this answered your question. Please write again if I can ever provide assistance.

Regards,

Mike