How to grow potatoes in bags

Particularly appealing to newcomers, but still enjoyed by experienced growers, harvesting tasty potatoes from bags and grow-sacks is simple and rewarding.

Growing potatoes in bags is very space saving because you don’t need an allotment or garden patch – grow-sacks and bags can be placed on patios, decking and concreted spaces and are easily planted and cared for.

First earlies, second earlies, salad and maincrop varieties of potato can all be grown successfully inside bags and sacks.

How to chit potatoes

Potatoes will usually arrive to you as ‘seed potatoes’ from late winter or early spring.

To give them a head start, place these in open egg boxes in a cool, light and dry place, such as a porch. The potatoes will then ‘chit’ and grow stems, ready for planting in the bags.

Where to grow potatoes in bags

Potato bags and grow-sacks are best placed in sunny, warm locations. They can be started from around February inside a greenhouse or conservatory, then placed outside when frost risks have gone.

How to plant potatoes in bags

At the correct planting time, place about five tubers on top of 8inches (20cm) of good quality compost inside the bag or sack.

  • Cover with 4inches (10cm) of compost.
  • As plants grow and shoots appear, add more compost to cover the shoots.
  • Repeat this until the soil is 2inches (5cm) from the top of the bag.
  • Keep the compost moist, being careful not to saturate the soil.

How to feed potatoes in bags

  • Fertiliser can be added at the rate indicated on its packet or bottle.
  • Use either a potato fertiliser, or good general-purpose feed at planting and each time you ‘earth up’. Earthing up is the process of adding a new soil layer.
  • Don’t use fertiliser that’s high in potash as this may delay maturity.

How to harvest potatoes in bags

When the flowers are fully mature and open, which will usually be around June or July time, first, second and salad varieties are ready to harvest.

Either dig around in the soil with your hand to feel for potatoes, moving any excess soil into a spare container, or empty the bag out into a wheelbarrow and sift through the compost.

Maincrop potatoes can be lifted from bags from September onwards and be stored in cool, dark, frost-free areas in hessian sacks.

Harvest once leaves and stems have yellowed.