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Growing potatoes in containers in the UK

Updated: October 2026

You have a patio, a balcony or a strip of garden, and a pack of eleven seed potatoes that will not fit in one bag. Earlies are the plants that belong in a pot. A container at least 30 cm wide and deep, with holes in the base, and one tuber for each 30 cm of diameter, is the Royal Horticultural Society starting point. A sack with no drainage, or a whole pack tipped into one tub, is how the crop rots or starves. The listings are on our [seed potatoes](/hub/root-vegetables/seed-potatoes) comparison. We did not weigh a harvest. A grow-bag product is not in this comparison.

You have a patio, a balcony or a strip of garden, and a pack of eleven seed potatoes that will not fit in one bag. Earlies are the plants that belong in a pot.

Our top picks

Carbeth Plants Carbeth 3 kg three-variety mix

Best overall

Carbeth Plants Carbeth 3 kg three-variety mix
9.4/10about £14.99
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Carbeth Plants Carbeth International Kidney 2 kg

Alternative

Carbeth Plants Carbeth International Kidney 2 kg
9.2/10about £11.99
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Carbeth Plants Carbeth Maris Piper 11 tubers

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Carbeth Plants Carbeth Maris Piper 11 tubers
8.8/10about £10.99
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On this page
  1. 1.Why earlies suit a pot
  2. 2.Size, compost and how many tubers
  3. 3.Drainage and watering
  4. 4.Which packs in this set mention containers

Why earlies suit a pot

The RHS prefers earlies in containers because the plants are smaller and they finish while a maincrop is still filling. A first early such as Pentland Javelin or Arran Pilot, or a second early such as Charlotte, matches that shape. The pot runs out of root space long before a maincrop runs out of season. Why earlies finish sooner is on first early versus maincrop. A maincrop can still go in a container if you accept a smaller crop than a row in the ground. The Maris Piper seller does say containers, grow bags and beds. One reviewer of that pack had no harvest from a trough in hot weather. That is one report, not a rate. Golden Wonder is sold as a late maincrop, and the seller does not give a pot.

Size, compost and how many tubers

Use a container at least 30 cm wide and at least 30 cm deep. Half-fill it with about 15 cm of peat-free compost, set the seed potato, and add more compost as the shoots grow, leaving some leaf in the light. The density rule is one seed potato per 30 cm of pot diameter. A 30 cm pot takes one tuber. A shorter RHS feature says an 8 to 10 litre container can be enough. Do not merge that aside into a new size. Simply Seed says one tuber in 30 litres and three in 40 litres or larger. Do not average one and three into two and call it the rule. An 11-tuber pack is not one bag. Plant what the containers can hold, and keep spare tubers for another pot rather than burying the surplus under the first one. Chitting and the open-ground trench are on how to plant seed potatoes.
Carbeth Plants Carbeth 3 kg three-variety mix

Testsieger

Carbeth Plants Carbeth 3 kg three-variety mix
9.4/10about £14.99
View offer

Drainage and watering

Compost that sits in water rots the seed. Any sack needs holes in the base, and the bag should be raised off the ground so those holes can actually drain. A pot on a solid saucer that stays full is the same problem. Bags also dry out in hot weather, especially against a sunny wall. Keep the compost moist, not flooded and not dust-dry. As shoots reach up, add peat-free compost and leave leaf in the light. The RHS school sheet says discard green potatoes. The Food Standards Agency says you can cut green parts away and should reject the potato if the rest still tastes bitter. A green tuber in a pot is not a harmless extra you scrub and eat. Water in the morning, and do not leave the bag standing in a tray of warm water afterwards.

Which packs in this set mention containers

Quote the seller, and only where the listing actually says a pot or a bag. Maris Piper states containers, grow bags and beds. The 3 kg mix states bags, tubs and raised beds. International Kidney states beds, containers and grow bags. Those are claims about where the seller says you may plant. They are not measured yields. Pentland Javelin, Arran Pilot, Swift and the Christmas mix do not give a pot size in the bullets. Do not read those four as container products on the strength of a heading. Golden Wonder names allotments, raised beds and vegetable gardens. Use that as open ground. A container decides the space. It does not decide whether you wanted a waxy salad or a floury chip potato.

Common questions

How many tubers go in?
One seed potato per 30 cm of pot diameter, in the RHS rule. A 30 cm pot takes one. Three tubers in that same 30 cm pot is a merchant or allotment habit, not the RHS density. An 11-tuber pack therefore needs several pots, or a bed for the ones that will not fit.
Do I need drainage holes?
Yes. Pierce holes in any sack, and raise the bag so the holes are not sealed against the ground. Compost sitting in a full saucer stays wet and the seed rots. Keep the compost moist. Do not leave it flooded, and do not leave it baked.
Are maincrops a good idea in a small bag?
They are the weaker idea. Earlies finish sooner and the plants are smaller. A maincrop stays into late summer and wants more space, so a small bag cuts the crop compared with a row. Use a large container if you insist, and plant one tuber per 30 cm of width.
How do I stop tubers going green in a pot?
Keep them covered. Add compost as the stems grow, and leave leaf in the light, just as you would earth up a row. If a tuber has already greened, the RHS school sheet says discard it. The FSA says cut the green parts away and reject the potato if the rest is still bitter. Use both. Scrubbing a green potato and serving it is not the advice on either source.
What if the bag dried out in a hot spell?
Water so the compost is moist again, and move the bag off a scorching wall if you can. One Maris Piper reviewer reported no crop from a trough in hot weather. That is a single review, not a percentage. Do not correct a dry spell by standing the container in a deep tray that never empties.

Related pages

Best seed potatoes

Seed potatoes

Buy certified seed potatoes: labels, counts and risk

First early vs maincrop potatoes: date, space and blight

How to plant seed potatoes: chit, spacing and earthing

Sources

Public UK sources, checked with the amazon.co.uk listings of 15 October 2026. Shelf prices and star lines are the figures in the display file. This page did not visit a garden centre.

  1. GOV.UK: Seed Potato Classification Scheme (retrieved 15 October 2026)
  2. Seed Potatoes (England) Regulations 2015 (retrieved 15 October 2026)
  3. SASA: Seed and ware potatoes classification (retrieved 15 October 2026)
  4. DAERA: Seed potatoes (retrieved 15 October 2026)
  5. GOV.UK: Farm-saved seed (retrieved 15 October 2026)
  6. RHS: How to grow potatoes (retrieved 15 October 2026)
  7. RHS: Potato blight (retrieved 15 October 2026)
  8. Potato Council: Growing healthy seed potatoes (retrieved 15 October 2026)