went to dig up any remaining spuds out off the ground and most are rotten ,i pesume theve been left in to long some have cracks which looks like that led to the roting ,when is the latest i can lift to avoid rotting ?
Depends what type they are, the ones that I've left in the ground the longest are PFA dug up in November.
I tipped out some last week from the toy tubs and dustbin and they were OK and eaten already, I still have a tub left with them in. ::)
I lift mine as soon as I think they are ready as the longer they stay in the ground the more likely they are to have slug damage. Actually I tend to wait until the first slug holes appear and then I life the whole lot. Is there any real advantage to leaving them in the ground? Maybe you have storage space issues? If so, maybe a proper potato clamp would work better than just leaving them where they grew. I've never tried one though.
PFA and COngo end of October/early November is as late as I let mine go.... then you'll find a few perfect ones left in all winter when you're digging in spring...always.....
Mine are all up and into store by the end of September. Chances of any left in the ground being of use after this date is slim. I have one sack left so most have kept well.
Wireworm, slugs and wet would most likely ruin them if left on my plot much after the end of September.