Potatoes grown in a sack

.Hi,

I am sorry if this is a simple question but I have not been able to find an answer elsewhere.

I am going potatoes in a sack for the first time. 

I should get some ‘earlies’ in late June / July and a main crop in September.  My question is after I have harvested the ‘earlies’ do I start again by adding new compost and new tumbers or do I leave the original tumbers and compost in the sack and just take out the ‘earlies’ when harvesting lose in late June?

Many thanks.

Once you harvest first earlies, that's it for this year. The seed potatoes you planted to produce the potatoes you harvested, will have turned to mush, therefore, no longer viable. You will need to clean the sack out and use the compost for something else.

It is the norm to plant potatoes between March and April.

First/second earlies - end march to mid april                                                         Main crop - mid april to late april

I have tried doing this for three years with only a few potatoes being produced. I have now given up on sacks and plant in the open ground. Problems there are slug damage and blight, but earlies lifted in June/July are usually OK. Growing in a bag requires carefull watering and regular feeding and must be a skill some people master and others don't. They also have to be cropped all at once which is not ideal.