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Best citrus compost UK: litres, drainage, and price

Updated: October 2026

A lemon on a UK patio usually arrives in a small nursery pot, and the first useful decision is how many litres of citrus compost you actually need before you look at stars. This buying guide stays with the eight bags in our [citrus soil comparison](/hub/trees-and-palms/citrus-soil), using amazon.co.uk prices from 19 October 2026. It covers volume, what the listing should name for drainage, and what a peat-free line does and does not mean. The named top pick and the best-value larger bag are on the [best citrus potting mix](/hub/trees-and-palms/citrus-soil/sub/citrus-soil-best) page.

A lemon on a UK patio usually arrives in a small nursery pot, and the first useful decision is how many litres of citrus compost you actually need before you look at stars.

Our top picks

Topline Topline Citrus Potting Mix (2 × 10 L)

Best overall

Topline Topline Citrus Potting Mix (2 × 10 L)
7.0/10about £20
View offer
Westland Westland Citrus Potting Mix (2 × 10 L)

Rank 2

Westland Westland Citrus Potting Mix (2 × 10 L)
8.8/10about £18.58
View offer
UK GROW UK GROW Citrus Potting Mix (25 L)

Best value

UK GROW UK GROW Citrus Potting Mix (25 L)
6.2/10about £22.99
View offer
On this page
  1. 1.How many litres a patio lemon needs
  2. 2.What the mix has to do
  3. 3.What this Amazon set costs per litre
  4. 4.What the bag does not replace

How many litres a patio lemon needs

Match the bag to the job, then to the pot you already own. A 1 litre pouch, such as POT CULTURE at £7.99 or Plantalaya at £8.99, is a top-up for a windowsill plant or a handful around a seedling. A single 10 litre bag, Topline at £11.99 or UK GROW at £13.99, covers a top-dress or a small step into a slightly wider pot. A 20 to 25 litre purchase is the realistic bag for one established patio tree. When the volume is settled, the next question is whether the bag is a citrus mix or a general compost with a citrus picture on it. That difference is the subject of citrus compost versus multipurpose.

What the mix has to do

Citrus in a container need a mix that drains, sits mildly acid to neutral, and does not stay sodden when you bring the pot under cover. The Royal Horticultural Society points growers to a peat-free loam-based compost with about 20 per cent grit, or to John Innes No. 2 or No. 3 plus that grit. Thompson & Morgan cite about pH 6–6.5. A listing should name perlite, grit, or clay granules rather than only “nutrient rich”. Ericaceous compost is the wrong shortcut. It is blended for rhododendrons and blueberries. Westland says its citrus mix is not for ericaceous plants. The bag does not fruit the tree by itself.
Topline Topline Citrus Potting Mix (2 × 10 L)

Testsieger

Topline Topline Citrus Potting Mix (2 × 10 L)
7.0/10about £20
View offer

What this Amazon set costs per litre

Price per litre on 19 October 2026 falls into three bands. The 1 litre sizes are about £8 to £9 a litre. The single 10 litre bags are about £1.20 (Topline, £11.99) and about £1.40 (UK GROW, £13.99). The 20–25 litre buys are about 92p to £1 a litre: UK GROW 25 litres at £22.99 is the lowest, Westland’s 20 litres at £18.58 is about 93p, POT CULTURE 20 litres at £19.99 is about £1, and Topline’s 20 litres at £20.00 is £1. The best-value badge on the 25 litre UK GROW bag is the unit price only. It is not a claim that the reviews are stronger. If you are about to move the tree, the litres you buy should follow the pot step in how to repot a lemon tree.

What the bag does not replace

A specialist bag does not replace winter sense or a citrus feed. The RHS tells you not to leave the pot standing in water, and to water with rainwater, because hard tap water is alkaline and can push the compost the wrong way over time. A saucer full of water after a generous drink will undo a free-draining mix, whether you paid 92p a litre or £9. The feed in the bag, where a brand even states one, runs out. None of these listings guarantees more fruit.

Common questions

How many litres do I need for one lemon?
For a top-dress or a small step up, a 10 litre bag is the size that matches the job in this set. For one established patio tree moving up a pot, plan on 20 to 25 litres, which is the Westland or Topline twin-pack, the POT CULTURE 20 litre bag, or the UK GROW 25 litre listing. A 1 litre pouch is a top-up. One Westland reviewer found 10 litres short for a medium pot, so check your pot before you assume a single 10 litre bag will finish the job.
Is a 1 litre pouch enough?
It is enough for a seedling, a windowsill top-up, or a very small pot. It is not enough for a patio repot. POT CULTURE’s 1 litre is £7.99 and Plantalaya’s is £8.99, about £8 to £9 a litre, against about 92p to £1 a litre for the 20–25 litre bags. You also do not get a separate review file for those pouches.
Does peat-free mean it is a citrus mix?
No. Peat-free describes the growing medium, not the crop. A peat-free multipurpose bag can still hold too much water and lack the grit or clay granules a potted lemon needs. In this set, only Westland and Topline state peat-free. POT CULTURE, UK GROW, and Plantalaya do not, so those rows stay unknown rather than “yes”.
Is peat compost illegal in England?
No. On 19 March 2026 the government said a retail ban would be legislated when parliamentary time allows. It was not in force on the date of these listings. Choosing peat-free follows RHS advice and the wording on the bag. It is not because a peat bag would be an illegal product.
What should the bag name for drainage?
Look for perlite, grit, or clay granules such as Seramis, plus a line that the mix is free-draining. Westland names Seramis and perlite. Topline names Seramis. POT CULTURE names P35 perlite and grit. UK GROW says free-draining and loam-based without naming perlite or grit. “Nutrient rich” on its own does not tell you the mix will shed water.

Related pages

Citrus soil for an indoor lemon

Citrus soil

Best citrus potting mix: UK top pick and best value

How to repot a lemon tree: UK pot size and watering

Citrus compost vs multipurpose for a long-lived lemon

Sources

Public UK sources from the research digest, used for this page in October 2026. Prices, stars and review counts are from the amazon.co.uk listings stored on 19 October 2026. Garden-centre shelf prices are not Amazon prices. This is not a laboratory test.

  1. RHS, How to grow citrus (retrieved October 2026)
  2. RHS, Citrus problems (retrieved October 2026)
  3. RHS lemon profile (retrieved October 2026)
  4. Westland Citrus Potting Mix (retrieved October 2026)
  5. Hansard written answer, 19 March 2026 (retrieved October 2026)
  6. Responsible Sourcing Scheme (retrieved October 2026)
  7. Thompson & Morgan citrus guide (retrieved October 2026)
  8. Pennells, Westland 10 L (retrieved October 2026)