i am looking to start planting my second crop of potatoes. I have just unearthed my last potatoe crop, and want to know can i use these as my second crop. They are Charlotte, can i just simply plant them back. Thanks.
No, if you re-plant them they will stay dormant until next year. However, you can buy seed potatoes which have been kept in cold storage and plant those now. They are usually advertised as "Christmas potatoes". These are usually grown in bags so they can be moved into a greenhouse though - it may be hit and miss if you plant them in the ground, but if there aren't any early frosts you could be OK.
No, they won't grow this season.
Both 'Charlotte' and 'Maris Peer' are available from T&M, and others no doubt, for later cropping,'Carlingford' is another variety, usually for xmas potatoes.
Better using certified seed anyway,less chance of virus problems, it's possible to replant in the same place if you feed the soil for the second crop.