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Tomato planter buying guide

Updated: October 2026

A tomato planter can mean four products on amazon.co.uk: a fabric pot, a box with a water reservoir, a pot-and-cage kit, or an insert in a compost grow bag. The twelve listings captured on 15 October 2026 are on the [tomato pot comparison](/hub/plant-accessories/tomato-pot). A tall trellis does not make a small root zone larger, and a product called self-watering still needs a working route between its tank and the compost. The Products Compared editorial team wrote this on 16 October 2026 from those listings and RHS guidance, without a lab trial. A qualifying purchase through our links can earn a commission at no extra cost to you.

A tomato planter can mean four products on amazon.co.uk: a fabric pot, a box with a water reservoir, a pot-and-cage kit, or an insert in a compost grow bag.

Our top picks

Mactoou Mactoou 7 gallon fabric bags

Best overall

Mactoou Mactoou 7 gallon fabric bags
9.2/10about £14.99
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Mactoou Mactoou 3 gallon fabric bags

Best value

Mactoou Mactoou 3 gallon fabric bags
9.2/10about £11.86
View offer
MQJIAZHI MQJIAZHI 130 cm planter

Alternative

MQJIAZHI MQJIAZHI 130 cm planter
8.4/10about £11.99
View offer
On this page
  1. 1.What you are actually buying
  2. 2.How much compost one tomato plant needs
  3. 3.Reservoir, fabric pot or grow-bag insert
  4. 4.When the listing disagrees with itself
  5. 5.What to do after choosing

What you are actually buying

A fabric pot is a standalone compost container with porous sides. It folds flat and is difficult to waterlog, and it can lose moisture quickly in sun or wind. The Mactoou and OFFCUP products here are five-packs, so read the printed capacity as the size of each bag. A reservoir planter stores water below the compost. That does not mean every part of the compost is wet. A pot-and-cage kit puts a relatively small base under stackable supports. A 140 cm frame on a light base is not a deep planter. An insert such as the 11 cm DIVCHI product sits in a compost grow bag. It is a watering and support point, not the whole pot.

How much compost one tomato plant needs

The RHS advises one tomato plant in a pot 30–45 cm wide, or two plants in a standard compost growing bag. A larger volume holds water more steadily and adds weight under a tall plant. Measure the usable internal pot, not the cage height. Stated capacities in this set run from a 9.6 litre reservoir box to a 27 litre Mactoou fabric bag. That 27 litre bag is the closest fabric option here to a substantial one-plant container. Its shared review line is not evidence for that size alone. A small box may fit a tight corner, and it needs more frequent checking. Two support towers do not make the root zone large enough for two mature cordons.
Mactoou Mactoou 7 gallon fabric bags

Testsieger

Mactoou Mactoou 7 gallon fabric bags
9.2/10about £14.99
View offer

Reservoir, fabric pot or grow-bag insert

Choose a fabric pot if you can water regularly and want straightforward drainage. It stores flat and moves easily while empty. Dark fabric can warm in direct sun, and compost may dry at the edges first. A reservoir suits a missed day only after you test it. Water the compost from above at first, and check that moisture moves up from the tank. An inlet can block, a separator can be fitted wrongly, and rain can fill a tank the plant is not using. The self-watering planter versus fabric bag guide covers that choice. Choose an insert only if you already use a compost grow bag. It tidies watering and cane placement. It does not create the volume of a standalone planter. Peat compost remains legal to buy. The RHS prefers a peat-free mix, and none of these planters includes the liquid feed you will want once fruit forms.

When the listing disagrees with itself

Amazon variation pages can put several sizes under one rating. Both Mactoou listings show 4.6 from 2,607 ratings, one at 12 litres and one at 27. That is not 2,607 reviews of each capacity. Treat the stars as the variation family, then look for text that names the size you will buy. Check dimensions the same way. OFFCUP prints measurements that do not sit neatly with its capacity claim, and JQTOP and MQUPIN need the same check against the selected option. Compare title, image and dimensions before you order. A file can also mix in a potting mat. The best tomato planter picks from this set apply that check to the named listings.

What to do after choosing

Decide one plant or two, bush or cordon, and whether you can check moisture daily in warm weather. Choose compost volume next, then drainage or a reservoir, and only then frame height, pack count and price. A cordon still needs a support you trust. After you buy, follow the guide to growing tomatoes in pots for hardening off, planting depth, watering, feeding and tying in.

Common questions

What size pot does one tomato plant need?
The RHS recommends one tomato plant in a pot 30–45 cm across. Aim wider for a cordon, where space and safe loading allow, because more compost dries more slowly.
Is a fabric pot the same as a compost grow bag?
No. A fabric pot is a reusable permeable container. A compost grow bag is a sealed bag of growing medium that becomes the container when you open and plant it. Drainage, shape and support differ.
Can two tomato plants share a 10–20 litre box?
That is tight for two mature plants, especially cordons. Two support positions do not add root volume. The RHS guide is one plant in a 30–45 cm pot, or two in a standard growing bag.
Do bush tomatoes need a trellis?
Bush tomatoes generally need less training than cordons, but fruiting stems may still need short stakes. A full-height stackable trellis can be unnecessary. On an exposed patio, extra height can also increase the leverage on a light pot.
Why are two capacities printed on one listing?
One figure may belong to a different size variation, the entire multipack or an approximate conversion. Select the exact option and compare its title, dimensions and images. If they still conflict, treat the capacity as unverified rather than choosing the most favourable number.
Does a higher star rating mean a larger planter?
No. Stars can be shared across sizes. Both Mactoou packs show 4.6 from 2,607 reviews, at 12 litres and at 27. Check litres on the variation you select.

Related pages

Tomato containers on a UK patio

Tomato pots

Best tomato planter UK: strongest picks in this set

How to grow tomatoes in pots: UK timing and watering

Tomato pot for a patio or balcony: stability first

Self-watering tomato planter versus a fabric grow bag

Sources

Public UK sources for pot size, watering, blight, peat and product safety, plus the twelve amazon.co.uk listings in the display file, captured on 15 October 2026. Shelf prices and star lines are those UK figures.

  1. RHS: How to grow tomatoes (retrieved 16 October 2026)
  2. RHS: Vegetables in containers (retrieved 16 October 2026)
  3. RHS: Blossom end rot (retrieved 16 October 2026)
  4. RHS: Tomato blight (retrieved 16 October 2026)
  5. RHS: Peat-free compost choices (retrieved 16 October 2026)
  6. Defra letter, 29 January 2026, peat and parliamentary time (retrieved 16 October 2026)
  7. GOV.UK: Product safety advice for businesses (retrieved 16 October 2026)
  8. Consumer Rights Act 2015 (retrieved 16 October 2026)