The best terra preta, compared.
Top pick: CANNA variant, 1 Terra Flores Best value: Home Terra Preta, Kindle – Best value only as the £2.99 English Kindle, with 42 pages and two ratings as the limit. Updated October 2026.
Terra preta is the dark, charcoal-rich soil of the Amazon, not a brand. In a UK garden the practical version is biochar mixed with compost. Plain char holds water and nutrients but is not a fertiliser. The Royal Horticultural Society says straight biochar suits dense or poorly drained soil, and enriched blends suit planting. There is no biochar sack in the folder. Judge a row by whether it is biochar, whether any char is charged, and whether the bag is peat. TERRA is that firm's name for peat potting mixes and for Terra and Terra liquids. The [terra preta buying guide](/hub/diy-supplies/terra-preta/sub/terra-preta-buying-guide) sets the decision order before you add a bag to the basket.
Terra preta is the dark, charcoal-rich soil of the Amazon, not a brand. In a UK garden the practical version is biochar mixed with compost. Plain char holds water and nutrients but is not a fertiliser.
42 products checked · 56 hrs invested · +16,800 readers
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Personal buying guide
Question 1 of 2
What are you trying to buy?
The style name is 1 Terra Flores at £20.92, with flowering-nutrient bullets and a single review at 5.0 dated 30 January 2020. The title offers 1, 5 and 10 litre options, and no liquid-volume cell is filled in. That reviewer wrote that it does what it says, that you pay for the name, and that it suited an orange tree better than a lemon tree. The same text appears on the Vega variant, so this is one comment, not two buyers. A 5.0 from one review is the whole sample. At £20.92 with an empty litre cell, the file does not show the volume you would pay for. It reads as a flower-feed style with a size gap.
Pros
Cons
Best for: You already know which litre size the live page will send and you can accept a single 2020 review.
Less suitable: You need a filled volume cell, or more than one review.
Specifications
Common questions
How many litres are in the pack?
The title offers 1, 5 and 10 litre options and the style says 1 Terra Flores. No liquid-volume cell is filled in.
What does the only review say?
On 30 January 2020 the reviewer wrote that it does what it says, that you pay for the name, and that it suited an orange tree better than a lemon tree.
Is a 5.0 rating a large sample?
No. The count is 1.
The style name says 1 Terra Vega at £20.92, the bullets describe Terra Flores and the flowering phase, and the liquid-volume cell says 10 litres. The only review matches the Flores variant word for word and is dated 30 January 2020, so it is not a separate test of this style. A 5.0 from that one review is the same thin sample. The price matches the Flores variant at £20.92, which does not tell you whether the cell's 10 litres or the style's 1 is what would arrive. Until the file agrees on Vega or Flores and on the volume, this is the least usable listing in the folder. A bag of black earth is a different product from either reading of the page.
Pros
Cons
Best for: Only after you have opened the live page and confirmed Vega or Flores and 1 litre or 10 litres.
Less suitable: Anyone who would trust the style name, the bullets, and the volume cell as one product.
Specifications
Common questions
Is this Vega or Flores?
The style name says 1 Terra Vega. The bullets describe Terra Flores and the flowering phase. The file does not resolve it.
Is it 1 litre or 10 litres?
The style says 1 Terra Vega. The liquid-volume cell says 10 litres. The price is £20.92, the same as the Flores variant.
Is the review independent of the other variant?
The only review matches the Flores variant word for word and is dated 30 January 2020.
The title says CANNA Terra Flores, 1 litre, at £16.66, rated 4.8 from 12 reviews. The liquid-volume cell says 1 litre and the item weight is 340 g, which the file does not reconcile. The form cell reads líquido. Bullets say it keeps spider mites, aphids, mealy bugs, whitefly, and mildew under control. The three UK reviews do not mention pests. They describe a plant feed, and one reviewer used a full dose first and saw a small nutrient burn on tomatoes. A 4.8 from 12 is a high star line on a small sample. The pest wording and the feed reviews are two different products on one page, so you would confirm the live listing before you treat it as either a spray or a flower nutrient.
Pros
Cons
Best for: You have checked the live page and you are buying a flower feed, knowing the pest bullets are not what the UK reviews describe.
Less suitable: You want a proven mite spray, or a listing whose weight matches 1 litre.
Specifications
Common questions
Does this listing prove it kills spider mites?
The bullets say it keeps spider mites, aphids, mealy bugs, and whitefly under control. The three UK reviews do not mention pests. They describe a plant feed.
What went wrong in the reviews?
One UK reviewer used a full dose first and saw a small nutrient burn on tomatoes.
Is the weight in line with 1 litre?
The liquid volume cell says 1 litre. Item weight is 340 g. The file does not explain the gap.
This CANNA Terra Vega 1 litre is the only Vega file here that prints NPK 3-1-4, at £12.20, model ctv1000, listed weight 1.1 kg, rated 4.7 from 463. The title states a dose of 1 litre for 200 litres of water. Several reviewers say they use about half of a printed rate. The rating line is on the UK listing, and the review texts saved in the file are from Germany, France, and Italy, so they are not notes from UK gardens. One review mentions a Dutch label. At £12.20 it is £1.24 below the other 1 litre Vega row. The analysis belongs to this feed. It does not transfer to the peat bags, and it does not describe terra preta.
Pros
Cons
Best for: You want Terra Vega with NPK 3-1-4 printed on the title and you will read the UK star line without treating the saved reviews as British.
Less suitable: You need UK review texts, or an analysis you can copy onto a compost bag.
Specifications
Common questions
What analysis is printed?
The title says NPK 3-1-4. The other Vega files in this folder do not print that analysis.
Are the written reviews from the UK?
The rating line is on the UK listing: 4.7 from 463. The review texts saved in the file are from Germany, France, and Italy.
How is the dose stated?
The title says 1 litre for 200 litres of water. Several reviewers say they use about half of a printed rate.
This CANNA Terra Vega listing is a 1 litre liquid growth nutrient at £13.44, rated 4.6 from 510 reviews, model 05-205-050, weighing 1.18 kg. The file prints a mix of 40 ml per 10 litres, which is 4 ml per litre. That figure stays on this bottle: the 5 litre file prints 1:200 instead. A UK review reports indoor plants. The page asks whether the nutrient is organic and does not answer, while one UK review calls it organic, which is a comment rather than the specification. It is a feed for the growth stage of a potting mix. A terra preta bed is a different purchase.
Pros
Cons
Best for: You already use a CANNA peat mix and you want the 1 litre Vega bottle that prints 40 ml per 10 litres.
Less suitable: You want soil, or you would copy this rate onto the 5 litre bottle.
Specifications
Common questions
How much do you mix?
This listing prints 40 ml per 10 litres. That is 4 ml per litre. Do not copy the 1:200 line from the 5 litre file.
Is it terra preta?
No. It is CANNA Terra Vega, a liquid growth nutrient.
Does the file say it is organic?
The page asks and does not answer. One UK review calls it organic. That is not the specification.
This Books on Demand Kindle is a 42-page English file on homemade black soil, priced at £2.99, with a 3.1 MB download and ISBN 978-3756245437. The rating line is 4.5 from 2, and the saved listing has no review text, so the stars do not describe a garden. The publication date on the file is 12 July 2022, first edition. Forty-two pages is a short read beside the 194-page English print at £18.65. Two ratings are too small a sample to treat 4.5 as a checked method. At £2.99 it is the inexpensive English guide in this folder, and it still leaves you to buy or charge the char yourself.
Pros
Cons
Best for: You want the inexpensive English file in this folder and you will take the char and the charge from a bag label.
Less suitable: You want a long print method, or any sack of compost in the same order.
Specifications
Common questions
Is this soil?
No. It is a Kindle book of 42 pages at £2.99.
What language is the file?
English.
How long is it?
The file says 42 pages and a 3.1 MB download.
CANNA Terra Professional Plus is a peat potting mix listed at £21.48, with 4.4 from 849 reviews, the largest count in this folder. The title says 50 L and the volume cell says 47.5 litres, at a listed weight of 10 kg. UK reviews report indoor and outdoor use in pots and with houseplants, and they split on gnats, lumps, and moisture. Bullets and reviews name peat. The file claims starter nutrients and prints no NPK. If you already grow in a CANNA peat mix, this is the row with the review volume to read. If you searched for black earth, Terra on this bag is the CANNA line for a peat growing medium.
Pros
Cons
Best for: You already grow in CANNA peat and you want the mix with 849 reviews, after you accept the 47.5 litre cell.
Less suitable: You want biochar or a peat-free black-earth compost.
Specifications
Common questions
Is this terra preta?
No. The listing is CANNA Terra Professional Plus, a peat soil mix. Terra here is the brand line.
Can it be used indoors?
The page asks that question. UK reviews report indoor and outdoor use, including pots and houseplants.
What volume is printed?
The title says 50 L. The volume cell says 47.5 litres. Weight is 10 kg.
CANNA Terra Professional is listed at £18.99 for a 50 litre style, with 4.4 from 119 reviews and a weight of 14.5 kg. The title and the manufacturer line say CANNA, while the brand cell says SIXNEA, so the file does not agree on the maker. A bullet says peat-based products are being phased out from December 2023, which is a seller line and is not a peat-free claim. The packs cell says 3 while the chosen style is 50 litres, and the file does not say whether one bag or three arrives. UK reviews mention houseplants and a windowsill propagator. It is the cheaper 50 litre-style peat mix beside Professional Plus at £21.48, and it remains a peat growing medium.
Pros
Cons
Best for: You want the £18.99 CANNA peat style and you will check the live page for one bag versus three.
Less suitable: You need the brand field to match the title, or a peat-free biochar compost.
Specifications
Common questions
Is the brand CANNA or SIXNEA?
The title says CANNA Terra Professional. The brand cell says SIXNEA. The manufacturer line repeats CANNA.
Does the file say it is peat-free?
No. A bullet says peat-based products are being phased out from December 2023. That is not a peat-free claim.
Is it one bag or three?
The chosen style is 50 litres. The packs cell says 3. The file does not resolve that.
This CANNA Terra Vega bottle is 5 litres at £35.65, about £7.13 per litre against £12.20 and £13.44 for the 1 litre Vega files, rated 4.4 from 38 reviews. The model is 05-205-055 and the listed weight is 5.77 kg. The mix cell says 1:200, a different printed rate from the 40 ml per 10 litres on the £13.44 listing. The bullets say the spanner is sold separately, and one UK review says the photo showed a spanner and none arrived, so the bottle could not be opened. One UK review from January 2025 says the instructions were in French, and the file does not say that is true of every bottle. The lower price per litre holds only if you can open the bottle and read the sheet.
Pros
Cons
Best for: You will use 5 litres of Terra Vega and you can open the bottle without the spanner the bullets say is separate.
Less suitable: You need English instructions on every bottle, or a 1 litre size at £12.20 or £13.44.
Specifications
Common questions
Is a spanner in the box?
The bullets say the spanner is sold separately. One UK review says the photo showed a spanner and none arrived, so the bottle could not be opened.
What mix ratio is on this bottle's file?
1:200. The 1 litre listing prints 40 ml per 10 litres instead.
Were the instructions in English?
One UK review from January 2025 says the instructions were in French. The file does not say that is true of every bottle.
This Books on Demand Kindle is 66 pages in German at £2.49, rated 4.2 from 56, which is the largest review count among the four books. ISBN 978-3749457618. The review texts in the file are in German. One reviewer says terra preta is only mentioned in passing, and others treat the file as a short composting reference. Fifty-six ratings support the star line more firmly than the two ratings on the English Kindle. They still do not describe a UK bed, and they do not turn a side topic into a full black-earth manual. At £2.49 it is the lowest shelf price in the folder, for a German composting file.
Pros
Cons
Best for: You read German and you want a cheap composting Kindle, knowing terra preta is a side topic in at least one review.
Less suitable: You need English steps, or a sack of biochar compost.
Specifications
Common questions
Will this give me English steps?
No. The edition is marked German, and the review texts in the file are in German.
Do the reviews say it is a full terra preta manual?
One reviewer says terra preta is only mentioned in passing. Others treat it as a short composting reference.
What does it cost?
£2.49 for a 66-page Kindle.
This Acres U.S.A. print is a 194-page English guide to making black earth, listed at £18.65, weighing 445 g, with ISBN 978-1601732996 and a publication date of 1 January 2026. The amazon.co.uk line is 3.8 from 4 ratings, and the saved listing contains no review text, so those four stars do not describe a bed, a mix, or a season. It is the longest English title in this folder, which is why it leads the guide rows. Four ratings are a thin sample beside the hundreds of reviews on the CANNA bags and bottles. The pages can tell you a method. Soil, char, and compost remain a separate purchase, and the file gives you no reader account of what happened after someone followed the book.
Pros
Cons
Best for: You want a long English print on making black earth and you will still buy char or compost separately.
Less suitable: You need a bag this week, or a method already described by more than four ratings.
Specifications
Common questions
Is this a bag of terra preta?
No. The listing is a 194-page English print book from Acres U.S.A., priced at £18.65.
What language is it?
The file says English.
How many reviews are printed?
3.8 out of 5 from 4 ratings. The saved listing has no review text.
This epubli print runs to 222 pages in German, priced at £25.62, weighing 294 g, with ISBN 978-3565551460 and a publication date of 9 July 2026. The dimensions on the file are 14.81 x 1.27 x 21.01 cm. The saved listing has no star line, so there is no amazon.co.uk rating to set beside the method. The language cell says German, which leaves an English-speaking reader without steps they can follow. At £25.62 it is the dearest book in the folder. The page count is real, and the soil you would put in a bed is still a different product.
Pros
Cons
Best for: You read German and you want a long print, knowing the file has no rating line.
Less suitable: You need English steps, or you are comparing it with a bag of compost.
Specifications
Common questions
Is this an English guide?
No. The file says the language is German.
Is a star rating printed?
No rating line is in the saved listing.
Is this a sack of soil?
No. It is a 222-page print book at £25.62.
Twelve amazon.co.uk listings kept on 16 October 2026 are on this page. Scores are out of 100 and are not a laboratory test. They do not rank the wider UK biochar aisle, because this folder has no biochar sack. The four weights below sum to 100.
Match to the search
30%An English guide to black earth scores here. A German file scores less. A CANNA peat bag or liquid is a different product and stays low.
Stars and review count
25%Amazon stars and how many separate reviews sit behind them. A 5.0 from one review scores far below a 4.4 from 849. Two listings that share one review text are not two samples.
Price for what it is
25%Shelf prices are the figures in these files, judged against what the listing actually is. A £2.99 English Kindle is cheap for a short guide. A £20.92 variant with no agreed volume is not a bargain.
Listing honesty
20%Deductions for a missing rating line, no review text, a brand or volume clash, pest bullets the reviews do not support, and a duplicate review.
Match the title to biochar or black earth before you match a price. A CANNA Terra bag is a peat mix, and a CANNA Terra bottle is a liquid feed. A Kindle is a file, not soil. Stars on a peat mix do not describe a terra preta bed.
Terra preta is the dark, charcoal-rich anthropogenic soil of the Amazon. It is not a brand. In a UK garden the practical version is biochar mixed with compost, because plain char holds water and nutrients but is not a fertiliser. The Royal Horticultural Society says straight biochar suits aeration of dense or poorly drained soil, and enriched blends suit planting.
CANNA TERRA is that firm's peat potting mixes and its Vega and Flores liquids. A peat bag is not black earth, and a liquid is not a soil improver.
The Royal Horticultural Society says not to make biochar at home without specialist equipment, and not to dig in stove or barbecue charcoal.
Defra announced a retail ban by 2024. The RHS says no peat-ban statute is currently in force. A seller bullet about December 2023 is not that statute.
The first check is what the listing actually is. The two English books are guides: a 194-page print at about £18.65, rated 3.8 from 4 with no review text, and a 42-page Kindle at about £2.99, rated 4.5 from 2. The German print and the German Kindle do not give English steps, and one review says terra preta is only mentioned in passing. None of the four delivers a bag. CANNA TERRA shares the word Terra and is a different product.
If you buy biochar outside this folder, check whether it is charged. Garden Organic says uncharged biochar can lock nutrients up, so mix it with compost for a few weeks unless the label says pre-charged. Follow the bag for the rate. The trials they cite are around 1–2 kg per square metre, and char that does not rot away is usually added once, not monthly. Their note of about £20 for 10 kg is a note on biochar, not a price from these ASINs. Peat is the check on anything labelled Terra here.
Three typical situations, each with a recommendation from this comparison.
You will charge biochar or buy it already blended, and you want an English method before you order the char. Modern Grower's Guide to Terra Preta is a 194-page print at about £18.65, rated 3.8 from 4, with no review text. It does not supply the sack.
You searched the word terra and you already grow in a CANNA peat mix. Terra Professional Plus is about £21.48, with 4.4 from 849 reviews, a 50 L title and a 47.5 litre cell. It is a peat growing medium, not black earth.
You want the inexpensive English guide and you will take the char and the charge from a bag label. The Home Terra Preta Kindle is 42 pages at about £2.99, rated 4.5 from 2, with no review text. A German file does not give you English steps.
The highest score in this folder is Modern Grower's Guide to Terra Preta, and only as the long English guide. It is a 194-page print at about £18.65, rated 3.8 from 4, with no review text. It is a book, not a sack of terra preta. The best value is the Home Terra Preta Kindle at about £2.99, 42 pages and two ratings. The £2.49 German Kindle is cheaper and scores lower because the language, and a review that calls terra preta a side topic, do not serve an English search. Eight of the twelve listings are CANNA TERRA peat mixes or liquids. Do not read a CANNA bag as black earth.
Home Terra Preta, Kindle
Best value only as the £2.99 English Kindle, with 42 pages and two ratings as the limit.
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 for this comparison. amazon.co.uk listings were read on 16 October 2026.
This page contains affiliate links to amazon.co.uk. If you buy through them, we may earn a commission at no extra cost to you. Prices and ratings are from the 16 October 2026 listings. We did not run a laboratory soil test.
