when should I worry about no signs of asparagus

I grew some Martha washington asparagus from seed last year but it stayed in pots until I got my allotment in late summer.  I then planted them out 12 in all but as of yet nothing is showing and I am starting to think they were not robust enoguh for the winter we had.  I do not want to start rummaging as it could be that they will send up shoots soon.  I know that I need them to grow and leave them for 3 years maybe more since they were from seed.  Do I dig around and see if anything is happening?  To be honest I do not need the bed as I have enoguh growing space.