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Tomato Grow Bag vs Pot

Updated: October 2026

If your patio has room for either one large container or a low planter, the tomato grow bag vs pot decision is mainly about root volume, watering and how much choice you want over the compost. The short answer is conditional: use a large grow bag for two plants when you can check moisture frequently; use a 30–45 cm pot for one plant when you want a deeper root run and compost you select yourself. Our [tomato soil comparison](/hub/fertiliser-soil-and-bark-mulch/tomato-soil) shows the formats and prices we compared. Choose the container before the brand. A qualifying purchase can earn us a commission at no extra cost to you.

If your patio has room for either one large container or a low planter, the tomato grow bag vs pot decision is mainly about root volume, watering and how much choice you want over the compost.

Our top picks

UK GROW UK GROW tomato compost 10 litres

Best overall

UK GROW UK GROW tomato compost 10 litres
9.6/10about £11.99
View offer
Munnie Munnie multi-purpose compost 60 litres

Preis-Tipp

Munnie Munnie multi-purpose compost 60 litres
9.2/10about £9.34
View offer
2you 2you vegetable grow bag 30 litres

Alternative

2you 2you vegetable grow bag 30 litres
0.0/10about £9.99
View offer
On this page
  1. 1.What each format is for
  2. 2.Water, depth and drainage
  3. 3.Which to buy for your space
  4. 4.Bags in this comparison

What each format is for

The RHS recommends one tomato plant in a 30–45 cm pot and two plants in a standard growing bag. A pot gives one plant its own container. A grow bag shares one shallow reservoir between two plants, which saves floor space and pot cost, and means one watering mistake affects both. Which? advises at least 10 litres per plant. Gardeners' World suggests two plants in a 60 litre bag and three in a 75 litre bag. A 30 litre bag split between two plants is 15 litres each: above the Which? floor, and not the 60 litre example. A pot lets you choose the compost. A prefilled planter fixes the blend. The tomato compost buying guide compares litres, peat wording and feed claims once the container is chosen.

Water, depth and drainage

Grow bags are broad and shallow, so the upper layer can heat and dry quickly. The RHS notes that containers may need daily attention in hot conditions. Uneven moisture is associated with split fruit and blossom end rot. Check frequently and water according to the compost and weather, rather than on an automatic daily schedule. Peat-free mix can look dry on top while damp below. Which? found that daily watering in its six-week coir trial washed out feed and produced the worst tomato result among the methods tested. Do not assume every grow bag needs the same drainage treatment. Levington Tomorite says not to pierce the base, because the planter holds a reservoir. Westland Big Tom tells you to make holes underneath. Follow the bag you are holding, and use the planting and watering guide for the sequence.
UK GROW UK GROW tomato compost 10 litres

Testsieger

UK GROW UK GROW tomato compost 10 litres
9.6/10about £11.99
View offer

Which to buy for your space

Choose a grow bag for two plants in a long, low space when you can check moisture in hot weather and you want compost and container together. A larger bag is more forgiving than one that merely reaches 10 litres per plant. Choose a 30–45 cm pot for one plant when you want depth and control over the compost. Neither format is self-watering. The pot is our conditioned recommendation for one plant, because depth and a single plant are easier to manage. For two plants and close checking, a substantial grow bag is the more space-efficient choice.

Bags in this comparison

The 2you product is a 30 litre peat-free vegetable grow bag at £9.99. It names tomatoes, includes coir, wood fibre and plant fibre and claims feed for up to six weeks. Two plants would have 15 litres each. No Amazon review line was captured, and drainage directions are not in the captured fields. Miracle-Gro's 20 litre peat-free compost was £7.95 and claimed feed for up to three months. It can fill one pot above the 10 litre floor, but it is not a container. Add the pot before you compare it with a ready planter. UK GROW's 10 litre tomato compost cost £11.99. Reviewers report that it does not fill a large pot, peat-free status is not stated, and the listing shows a conflicting 1,000 ml unit count. It is a top-up, not a grow bag. See our conditioned top picks if you want a product recommendation.

Common questions

Is a grow bag better than a pot?
It is better for two plants when you want a ready-filled, space-efficient planter and can monitor water closely. A large pot is better for one plant when you want depth and control over the compost. Neither format is universally better. Volume and your watering routine decide.
How many tomato plants go in a grow bag?
The RHS says two plants in a standard growing bag. Gardeners' World uses two in 60 litres or three in 75 litres. Do not rely only on printed planting squares: check the bag volume and allow at least the cited 10 litres per plant.
What pot size replaces a grow bag?
For one plant, the RHS recommends a pot 30–45 cm in diameter. Two plants are better given separate suitable pots rather than crowded into one equivalent-width container. The required compost volume depends on the pot's shape and depth, not diameter alone.
Do grow bags dry out faster?
Their shallow shape can lose moisture quickly and two plants share the reserve, so they often need closer checking. Conditions, material and compost matter, however. Test below the surface rather than watering automatically because the top looks dry.
Should you cut drainage holes in a grow bag?
Follow the exact bag. Westland Big Tom calls for underside drainage holes, while Levington Tomorite says not to pierce the base. Those products manage water differently, so a universal instruction could damage the system you bought.
Is a 30 litre bag enough for two tomatoes?
It provides 15 litres per plant, above the 10 litre minimum cited by Which?, and follows the RHS two-per-bag pattern. It is still much smaller than the 60 litre two-plant example from Gardeners' World, so careful moisture management and realistic expectations are important.

Related pages

Tomato fertiliser compared

Tomato soil

Best Tomato Grow Bag UK: A Top Pick With Conditions

Tomato Compost Buying Guide: Litres, Then the Label

How to Plant Tomatoes in a Grow Bag: Drainage First

Peat-Free Tomato Compost: What the UK Label Must Say

Sources

Public UK sources used for this comparison; listings checked on amazon.co.uk. Last accessed 15 October 2026.

  1. RHS: How to grow tomatoes (retrieved 15 October 2026)
  2. RHS: Peat-free compost (retrieved 15 October 2026)
  3. RHS: Tomato blight (retrieved 15 October 2026)
  4. RHS: John Innes compost (retrieved 15 October 2026)
  5. RHS: Minimising health risks in the garden (retrieved 15 October 2026)
  6. Which?: How to grow tomatoes (retrieved 15 October 2026)
  7. Gardeners' World: tomatoes in a growing bag (retrieved 15 October 2026)
  8. Peat-Free Partnership: legislation timeline (retrieved 15 October 2026)