The best hydrangea soils, compared.
Top pick: SIC Ericaceous 50 L Best value: TerraGrade Ericaceous 50 L – Lowest price per title litre, about £0.20, at about £9.99. The 50 L title conflicts with a 44 L volume field. Updated October 2026.
Hydrangea soil is ericaceous compost: a lime-free, acidic bag sold for hydrangeas and for other acid-loving shrubs such as rhododendrons, azaleas, camellias and blueberries. You buy it in the UK when you want blue mophead or lacecap flowers, or when you are potting those shrubs. Colour-changing hydrangeas are blue in acid soil around pH 4.5 to 5, where aluminium is available, mauve near neutral, and pink in alkaline soil. White, red and green cultivars stay the colour they are. A suitable bag states peat-free when that is what you need, states a pH number, and gives one volume that agrees with the weight. If the wording does not say peat-free, treat the bag as likely to contain peat. Eco and organic do not mean peat-free. On alkaline ground, a container is the practical way to keep a blue flower blue. The checks for peat wording and litre clashes are in the [hydrangea soil buying guide](/hub/fertiliser-soil-and-bark-mulch/hydrangea-soil/sub/hydrangea-soil-buying-guide).
Hydrangea soil is ericaceous compost: a lime-free, acidic bag sold for hydrangeas and for other acid-loving shrubs such as rhododendrons, azaleas, camellias and blueberries.
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Personal buying guide
Question 1 of 2
What are you potting?
SIC is the clearest peat-free option in this set because the listing says peat-free and prints a pH of 4.0. That makes it easier to assess for acid-loving plants than bags that use only general low-pH wording. The 4.7-star line is backed by 445 amazon.co.uk reviews, although that is customer feedback rather than a growing trial. Hydrangeas are not named in the title, but a saved UK review specifically mentions using the compost for them. The main reservation is another pack-data conflict: the title says 50 L while the technical volume field says 60 litres, and the listed weight is 10 kg. At £12.49, it is a strong fit when peat-free wording and a printed pH matter more to you than perfectly consistent listing fields.
Pros
Cons
Best for: You want peat-free ericaceous compost with a printed pH for a blue hydrangea pot or another acid-loving plant.
Less suitable: You need the title, technical volume and weight fields to give one unambiguous pack size.
Specifications
Common questions
Does this listing say the compost is peat-free?
Yes. The title and a bullet say peat-free. One saved review still titled the bag “Excellent peat”; that is a reviewer’s label, not a lab result.
Does the listing print a pH number?
Yes. A bullet states pH 4.0. Title size is 50 L. Volume field: 60 Litres. Item weight: 10 kg.
Does the listing name hydrangeas?
No. The title names rhododendrons, azaleas, blueberries, heathers, and camellias. One saved UK review called the bag perfect for hydrangeas.
Green Haven combines a 50 L title with the largest review count in this set: 4.6 stars from 1,053 amazon.co.uk reviews. The listing also claims slow-release iron, which is relevant to ericaceous planting but does not establish a measured pH or a complete feeding schedule. Hydrangeas are not named in the listing, although one saved UK review describes using the compost for them. There is no stated peat-free claim, so the name and review count should not be read as evidence that it avoids peat. The product data also conflict, with 50 L in the title, 60 litres in the volume field and a listed weight of 11.6 kg. At £12.49, it suits a shopper who values a broader customer-feedback base and an iron claim, provided those missing and inconsistent specifications are acceptable.
Pros
Cons
Best for: A shopper who wants an ericaceous 50 L title with substantial customer feedback and a stated slow-release iron feature.
Less suitable: Anyone choosing specifically by peat-free certification, printed pH or consistent volume fields.
Specifications
Common questions
Does this listing say the compost is peat-free?
Peat line from the saved listing: not stated. A listing question asks whether the compost is organic and does not answer it in the saved file.
Do the litre figures on this listing agree?
Title size is 50 L. Volume field: 60 Litres. Item weight: 11.6 kg. Dimensions: 60 x 50 x 15 cm. Pack fields agree: No — title and volume field differ.
Does the listing name hydrangeas?
No. The title names blueberries, azaleas, camellias, and rhododendrons. One saved UK review called the bag really great for hydrangeas.
Laeto’s 100 L title is aimed at larger jobs and explicitly names hydrangeas among the suitable acid-loving plants. Its stored price of £26.99 is about 27p per title litre, but that calculation cannot confirm how much compost is actually supplied. The technical volume field says 40 litres and the listed weight is only 8.44 kg, so the pack description needs checking before this can be treated as a bulk bargain. The 4.6-star line from 656 reviews is shared with Laeto’s 20 L and 50 L variants, and some saved texts refer to other sizes or brands. The listing gives no peat-free claim, numerical pH or feed period. It is useful only when you want a hydrangea-named large title and accept that neither the volume nor the variant-specific review evidence is clear.
Pros
Cons
Best for: A larger hydrangea or acid-loving plant job where you can verify the delivered quantity before relying on the 100 L title.
Less suitable: Anyone who needs a confirmed bulk volume, variant-specific reviews or peat-free wording.
Specifications
Common questions
Does this listing say the compost is peat-free?
Peat line from the saved listing: not stated. If the bag does not say peat-free, do not treat it as peat-free.
Do the litre figures on this listing agree?
Title size is 100 L. Volume field: 40 Litres. Item weight: 8.44 kg. Pack fields agree: No — title and volume field differ.
Can the 656 ratings be read as this 100 L bag alone?
No. The same 4.6 from 656 and the same saved review texts appear on the Laeto 20 L and 50 L files. Some of those texts describe other litres or another brand.
Laeto’s 50 L variant is a mid-sized ericaceous option whose listing explicitly names hydrangeas. At £13.79, it costs about 28p per title litre and sits between the small Laeto bag and its 100 L title. The technical volume field says 20 litres and the listed weight is 6 kg, however, so you should not plan a potting job from the title alone. Its 4.6-star line from 656 reviews is shared with the 20 L and 100 L Laeto variants rather than being clean evidence for this bag. No peat-free claim, numerical pH or feed period is stated. It makes most sense when you want a manageable hydrangea-named bag and are prepared to confirm the actual pack details.
Pros
Cons
Best for: One or more hydrangea pots when you want a mid-sized title and can check the delivered bag before use.
Less suitable: A precisely calculated potting job or a buyer requiring peat-free wording and variant-specific feedback.
Specifications
Common questions
Does this listing say the compost is peat-free?
Peat line from the saved listing: not stated. If the bag does not say peat-free, do not treat it as peat-free.
Do the litre figures on this listing agree?
Title size is 50 L. Volume field: 20 Litres. Item weight: 6 kg. Pack fields agree: No — title and volume field differ.
Does the listing name hydrangeas?
Yes. A bullet and the item highlight name hydrangea with blueberries, azalea, and rhododendron. The 4.6 from 656 is shared with the 20 L and 100 L Laeto files.
Laeto’s 20 L title is the smallest bag in this comparison and explicitly names hydrangeas on the listing. Its listed 3 kg weight should make it easier to handle than the larger sacks, although the title says 20 L while the technical volume field says 10 litres. At £11.54, it works out at about 58p per title litre, the highest stored rate in this set. The 4.6-star line from 656 reviews is shared with the 50 L and 100 L Laeto variants, so it does not isolate this small bag’s performance. The listing does not state peat-free, a numerical pH or a feed period. It is chiefly a convenience choice for a modest potting job where avoiding a large leftover sack matters more than unit price.
Pros
Cons
Best for: A small hydrangea potting job where storage and carrying weight matter more than price per litre.
Less suitable: Several large pots, value-led buying or a job that needs a confirmed volume and peat-free specification.
Specifications
Common questions
Does this listing say the compost is peat-free?
Peat line from the saved listing: not stated. If the bag does not say peat-free, do not treat it as peat-free.
Do the litre figures on this listing agree?
Title size is 20 L. Volume field: 10 Litres. Item weight: 3 kg. Pack fields agree: No — title and volume field differ. About 58 pence per title litre.
Does the listing name hydrangeas?
Yes. A bullet and the item highlight name hydrangea. The 4.6 from 656 is shared with the 50 L and 100 L Laeto files.
TerraGrade is the lowest-priced 50 L title in this comparison at £9.99, which works out at about 20p per title litre. Its listing describes a low-pH ericaceous compost, and a saved UK review reports using it for hydrangea pots, although hydrangeas are not named in the product title or bullets. The strongest reason to consider it is the low stored price rather than a verified peat, pH or feed specification. The listing does not state that the compost is peat-free and gives no numerical pH. More importantly, the 50 L title conflicts with a 44 L volume field, while the listed weight is 14.9 kg. It is therefore a budget option only if you are comfortable checking the delivered bag against the description rather than assuming the title litres are confirmed.
Pros
Cons
Best for: A budget-conscious shopper who wants a large-title ericaceous bag and will verify the pack details on delivery.
Less suitable: Anyone who requires a confirmed peat-free mix, a printed pH or an unambiguous volume.
Specifications
Common questions
Does this listing say the compost is peat-free?
Peat line from the saved listing: not stated. If the bag does not say peat-free, do not treat it as peat-free.
Do the litre figures on this listing agree?
Title size is 50 L. Volume field: 44 Litres. Item weight: 14.9 kg. Pack fields agree: No — title and volume field differ.
Does the listing name hydrangeas?
No. The title and bullets name rhododendrons, azaleas, camellias, and blueberries. One saved UK review used the bag for hydrangea pots.
indigo is one of only two products in this set with peat-free wording, although that wording appears in the item-type field rather than the title. The listing also claims six months of slow-release feed, making it potentially convenient for container use without proving how the compost performs over that period. Its 46 L title costs £14.99, about 33p per title litre, while the technical volume field says 50 litres. There is no numerical pH and hydrangeas are not named on the listing. The 4.6-star rating comes from only three reviews, and the single saved UK review body offers almost no practical detail. Choose it for its peat-free item type and feed claim, not as a review-backed or precisely specified top pick.
Pros
Cons
Best for: A peat-free shopper who values a stated long-feed period and accepts limited customer evidence.
Less suitable: Anyone wanting a well-reviewed hydrangea-specific bag, a printed pH or fully consistent pack data.
Specifications
Common questions
Does this listing say the compost is peat-free?
The item type field says peat free compost. The title does not use those words. Stated pH: not stated.
Do the litre figures on this listing agree?
Title size is 46 L. Volume field: 50 Litres. Item weight: not stated. Pack fields agree: No — title and volume field differ.
How many saved reviews describe this bag?
The star line is 4.6 from 3. One saved UK body says “very good stuff” and nothing else. That is not enough to judge fill or the six-month feed claim.
Seven amazon.co.uk listings were scored from the pages and UK review notes already on file. There is no laboratory test. A peat-free line, a pH number or a feed period is the seller's claim. Where the title litres and the volume field disagree, both stay and the clash is a deduction. A 4.6-star row does not mean the bag is peat-free or that the litres agree. The highest score is the top pick. The best value is the lowest price per title litre, and it does not also take the top score. The weights below sum to 100.
Listing clarity
35%A peat-free line, a printed pH, a hydrangea name, and a feed period the listing actually states. SIC states peat-free and pH 4.0. The indigo peat-free wording is in the item type, with a six-month feed claim and no pH. Silence is not peat-free. Laeto names hydrangea. Green Haven, TerraGrade and the other bags do not.
Pack consistency
25%Title litres, the volume field and the kilograms, read together. Every listing here disagrees with itself. Examples: TerraGrade 50 L beside 44 L and 14.9 kg; SIC and Green Haven 50 L beside 60 L; Laeto 100 L beside 40 L and 8.44 kg; Laeto 50 L beside 20 L and 6 kg; Laeto 20 L beside 10 L and 3 kg.
Amazon evidence
20%Star rating on amazon.co.uk, then the size of that listing's review file. Green Haven is 4.6 from 1,053. SIC is 4.7 from 445. Laeto's 4.6 from 656 is the same line on the 20 L, 50 L and 100 L files, and some texts describe other brands. indigo is 4.6 from 3, so that file adds nothing here. TerraGrade is 4.6 from 100.
Value
20%Pounds per title litre, because the volume fields disagree. TerraGrade is about £0.20. SIC and Green Haven are about £0.25. Laeto 100 L is about £0.27, Laeto 50 L about £0.28, indigo about £0.33, and Laeto 20 L about £0.58. The rate uses the title litres only.
Match the plant and the bag wording before you match the star line. Prices below are amazon.co.uk prices on file. This is not a laboratory test. Title litres are used for price per litre because the volume fields disagree.
Hydrangea soil on amazon.co.uk is ericaceous compost for blue mopheads and lacecaps, and for other lime-hating shrubs. It is not a general substitute for multi-purpose compost, and it will not turn a white paniculata or an Annabelle blue. The Royal Horticultural Society says colour-changing hydrangeas are blue in acid soil around pH 4.5 to 5, where aluminium is available, mauve near neutral, and pink in alkaline soil, while white, red and green cultivars stay that colour.
Ericaceous compost is for blue mopheads and lacecaps, or for other lime-hating shrubs. It will not turn a white paniculata or an Annabelle blue. White, red and green cultivars stay that colour.
If the bag does not say peat-free, the RHS says it most likely is not. Eco and organic do not mean peat-free. A 2022 Defra announcement is not a ban already in force.
Title litres, the volume field and the kilograms have to be read together. Price per litre on this page uses the title litres because the other fields disagree. Goods must match their description.
Ericaceous compost is for blue mopheads and lacecaps, or for rhododendrons, azaleas, camellias, blueberries and similar lime-hating shrubs. It will not turn a white paniculata or an Annabelle blue. The RHS puts blue flowers at about pH 4.5 to 5, where aluminium is available, mauve near neutral, and pink in alkaline soil. On alkaline ground, use a container. If the bag does not say peat-free, treat it as likely to contain peat. Eco and organic are not a peat-free claim.
A 20 litre title suits a small pot. A 50 litre title is the usual sack. A 100 litre title is only a bargain if the fill matches the title. Read the title litres, the technical volume and the kilograms together. On these listings those fields disagree, so both figures stay. Price per litre uses the title litres for that reason. Prefer rainwater on a blue pot.
Three typical situations, each with a recommendation from this comparison.
On alkaline soil the practical route to a blue mophead is a container of lime-free compost. SIC Ericaceous 50 L is about £12.49, states peat-free and pH 4.0, and is 4.7 from 445 reviews. Hydrangeas are not named in the title. The title says 50 L and the volume field says 60 litres, with a listed weight of 10 kg. It will not turn a white paniculata blue.
Blueberries, camellias, azaleas and rhododendrons need a lime-free bag even when flower colour is not the aim. Green Haven Ericaceous 50 L is the top pick at about £12.49, with 4.6 from 1,053 reviews, and it claims slow-release iron. It does not say peat-free and it does not print a pH. The 50 L title sits beside a 60 L volume field and 11.6 kg.
TerraGrade Ericaceous 50 L is about £9.99, about 20p per title litre, the lowest rate in this set, with 4.6 from 100 reviews. The listing claims a low pH and does not print a number. It does not say peat-free. The title says 50 L, the volume field says 44 litres, and the listed weight is 14.9 kg. Check the delivered bag against the description.
The top pick is Green Haven Ericaceous 50 L at about £12.49. It has the highest score: 4.6 from 1,053 reviews, and a slow-release iron claim. It does not say peat-free, it does not print a pH, and the 50 L title sits beside a 60 L volume field and 11.6 kg. The best value is TerraGrade Ericaceous 50 L at about £9.99, about 20p per title litre, with 4.6 from 100 reviews. That listing claims a low pH without a number, and the 50 L title sits beside 44 L and 14.9 kg. SIC states peat-free and pH 4.0. Laeto names hydrangea, and the same 4.6 from 656 is shared across three sizes. The indigo bag states a peat-free item type and a six-month feed, from 3 reviews. None of these scores is a laboratory test.
TerraGrade Ericaceous 50 L
Lowest price per title litre, about £0.20, at about £9.99. The 50 L title conflicts with a 44 L volume field.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources checked for this page in October 2026. Prices, stars and review counts are from the seven amazon.co.uk listings on file. A peat-free line, a pH and a feed period are listing claims. Title litres are not treated as the fill when the volume field disagrees. This is not a laboratory test. A 2022 Defra announcement is not a ban already in force.
Expert source (DIY & tools): Lee Burkhill (Garden Ninja) (external profile) – public expert commentary used as a research source, not as a contributor to our pages.
This page contains affiliate links to amazon.co.uk (tag pcuk26-21). If you buy through them, we may earn a commission at no extra cost to you. Prices, stars and review counts are from the listings. This is not a laboratory test.
