The time to harvest potatoes depends upon the varieties you have chosen. Early varieties are ready to harvest when the flowers have appeared, main crop once the plants start to die back, main crop for over winter storage should have the plants trimmed when they start to die back and be left in the ground approx 2 weeks before they are lifted. If you want to double check your potatoes are ready and a reasonable size scrape away the soil near to the plant and you will unearth the tubers growing near the surface. If they are a good size then lift away, if not cover them up and leave a little longer.

How to harvest

Your main aims when lifting potatoes are to cause as little damage as possible to the tubers and to get them all out of the ground, no matter how small. Any tubers left behind will grow next season so you will soon find out if you have been successful, do not leave them in though as you will be storing up problems with pests and diseases in future. Use a flat tined fork if possible, a normal fork or spade will do otherwise.

Harvesting is best done in the dry weather as lifting wet soil is an unpleasant task and your potatoes will be muddy. When ready to harvest cut the plant stems away to approx 10 cm above soil level. If you are lifting main crop potatoes and planning to store them for winter, leave the tubers in the ground for another 10 – 14 days at this point. Push the fork into the soil a little distance from the plant and lift the roots into the trench, you will need to dig down a good spade depth to find all the tubers. Take a hold of the remaining stem and shake off the potatoes and soil, pick over the crop and gather in your harvest brushing off any loose soil.

Separate any; fork/spade damaged tubers, they are fine to eat so use these up first. diseased potatoes, should be disposed of, do not add them to your compost heap. green potatoes, are poisonous and should not be eaten.

Small potatoes look like pebbles so don’t be fooled, check through the soil thoroughly. Once found, if you can’t use them, dispose of them. The best way to do this is to cut them into tiny pieces and put them in your compost heap. If you add them to your compost heap whole they will probably grow.

What to use the old plants for

You guessed it, they make great compost.

Storing your harvest

Dirty potatoes store better than washed, once lifted brush off the loose soil and allow them to dry. Your potatoes will then need to be placed somewhere dark and dry. if the light gets to them they will start to go green and at that point they should not be eaten. 

Short term storage

It is best to place your potatoes in a potato bag in a cool, dry place until you are ready to use them, Potatoes should not be stored in a refrigerator. If you want to wash them make sure they are properly dry before you store them as they might start to rot and the smell is truly awful.

New potatoes will keep fine in a potato bag for up to 2 weeks, after this the skins start to toughen and the potatoes start to soften. As they get older “new” potatoes will keep in a potato bag for 1 month or so. They will need to be peeled rather than scraped but the potatoes themselves will taste fine once cooked, they are not as nice as the freshly dug treats though

Main crop potatoes will also keep well short term and should be treated in the same way as new potatoes. When first dug the skins may not have set and therefore they can be scraped..

Longer term storage

Main crop potatoes store well long term. Any surplus, lifted for immediate use, will keep in a potato bag in a cool place for many weeks before they start to soften. If storing longer term it is best to place the tubers in a covered wooden box, hessian or paper potato sack and keep them in a cool dark place such as a shed or garage. If exposed to light they will go green and should not be eaten. As the winter turns to spring the tubers will start to grow and you will need to start using them up, cut out the growing tips then peel and cook as usual. If they grow beyond this initial sprouting stage then the energy stored in the tuber will be used producing the new plant and will no longer be good to eat. Either dispose of them or grow them.

Frozen – fresh new potatoes freeze well but need to be blanched first, either in boiling water or oil, for 3 mins. Allow to cool completely before they are placed in ridged containers or freezer bags, label, date and place in the freezer.

Dried – yes perfectly possible but I wouldn’t go there, instant mash is freeze dried potato

Prserved - Potatoes are not ideal for pickles and chutney.

Canned and bottled - New potatoes can be bottled or tinned but don’t taste as good so unless you really need to I wouldn’t bother.

Happy harvesting!