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Seaweed fertiliser or fish, blood and bone in the UK

Updated: October 2026

Both bags can say natural fertiliser, and one is still a biostimulant while the other is an animal-meal soil feed. Seaweed fertiliser or fish, blood and bone is that format decision, including for vegan or stockfree gardeners. This page is from Peter F., the DIY and tools editor, on 21 October 2026. The nine amazon.co.uk listings are on the [natural fertiliser comparison](/hub/fertiliser-soil-and-bark-mulch/natural-fertiliser), read with RHS seaweed and biostimulant pages and GOV.UK animal-by-product rules. Nobody here ran a side-by-side plot. A qualifying Amazon purchase can earn a commission at no extra cost to you. A tonic fails a hungry bed. A meal fails a vegan diet or a grazing plot.

Both bags can say natural fertiliser, and one is still a biostimulant while the other is an animal-meal soil feed.

Our top picks

Sunshine Renewables UK Sunshine Renewables seaweed 20 L

Best overall

Sunshine Renewables UK Sunshine Renewables seaweed 20 L
9.4/10about £59.99
View offer
Maxicrop Maxicrop seaweed 2.5 L

Alternative

Maxicrop Maxicrop seaweed 2.5 L
9.2/10about £18.99
View offer
Topline Topline fish, blood and bone 8 kg

Best value

Topline Topline fish, blood and bone 8 kg
9.2/10about £18.98
View offer
On this page
  1. 1.They do different jobs
  2. 2.Which packs are meals, and which are tonics
  3. 3.Vegan, dogs, and the 50 kg garden exception
  4. 4.When the format fails the garden you have

They do different jobs

Fish, blood and bone is meant to supply nutrients in the soil over weeks. The Royal Horticultural Society groups it with animal-based organic fertilisers. Shop pages often print 3-9-3 or 5-5-6. Those figures are other brands. Topline 8 kg is 1:0:0, so it does not print Westland's numbers. The job is still a soil feed you water in. A seaweed extract here is a biostimulant. The RHS says unstandardised seaweed is not a true fertiliser unless it is fortified and labelled, and names Maxicrop as an extract that complements a feed. Trace elements and stress recovery are the claim. Declared nitrogen, phosphate and potash are not. Use both only as a meal in the soil and a tonic as a top-up, not as one dose, and not on a planting hole that already has Empathy. High nutrients can inhibit those fungi. A tomato potash liquid is a third product.

Which packs are meals, and which are tonics

The meals are Topline 8 kg at £18.98, 4.6 from 191, and bone meal 4 kg at £11.99, 4.6 from 115. The 8 kg tub is the general soil feed. Bone meal is phosphorus at planting. Neither is vegan. The 8 kg field is 1:0:0. Bone meal still has no grams. The tonics are Maxicrop 2.5 L at £18.99, 4.6 from 3,688, at 1:100, with Soil Association claimed, and Sunshine 6 L and 20 L at 1:400, with 8 and 9 reviews and no control body. A litre price without those ratios is empty. Tomato, lawn, and acer feeds stay on best natural fertiliser. Maxicrop 2.5 L is the tonic with evidence, not the best fertiliser in Britain.
Sunshine Renewables UK Sunshine Renewables seaweed 20 L

Testsieger

Sunshine Renewables UK Sunshine Renewables seaweed 20 L
9.4/10about £59.99
View offer

Vegan, dogs, and the 50 kg garden exception

Animal meals are not vegan and not stockfree. Stockfree and vegan-organic standards ban animal and fish by-products and allow animal-input-free seaweed as a supplementary tonic. Some bottles are blends, so read the ingredients. Organic in a title does not make a meal stockfree. Dogs eat fish, blood and bone. Mix the meal into the soil. Westland's grazing limits, two months for pigs and three weeks for other farmed animals, are Westland's wording. A dog that eats a large amount of bone meal needs a vet. There is no dose here. Category 1 animal by-products cannot be fertiliser. Retail packs of 50 kg or less are exempt from the farm mixing-component rule, so an 8 kg tub is a garden sack. That does not make it vegan. Dilution and watering-in are on how to use natural fertiliser.

When the format fails the garden you have

Choose the meal for a bed when you will handle animal by-products. Topline 8 kg is the general bed. Bone meal is roots at planting. Skip both for a vegan plot, grazing livestock, or a printed analysis. Choose Maxicrop 2.5 L for 1:100 and a large review sample. Choose Sunshine for 1:400 in volume and 8 or 9 reviews. Seaweed fails as the only feed on a hungry bed. Fish, blood and bone fails a stockfree garden. Do not stack a heavy meal on Empathy, or treat the 20 L price as proof it beats Maxicrop without each ratio. An empty bed and a non-vegan diet point to the meal. An already fed bed, or no animal by-products, points to the tonic.

Common questions

Is seaweed a fertiliser or a tonic?
In these listings it is a tonic. The RHS treats unstandardised seaweed as not a true fertiliser, and Maxicrop as an extract that complements a feed. Fortified, labelled seaweed would be a different pack.
When do I need fish, blood and bone instead?
When the job is a soil meal for a bed or a hungry crop and you will handle animal by-products. A tonic will not print the NPK that meal is sold for, and Topline still does not print a usable analysis on this listing.
I garden vegan. Which of these listings can I use?
The seaweed bottles, after you read the ingredients. Skip Topline 8 kg and bone meal. Organic on a meal bag does not make it stockfree.
Can I use both in the same bed?
Yes as a meal in the soil and a tonic as a top-up, not as a combined dose. Do not pile the meal onto Empathy's mycorrhizal food.
Does organic on a meal bag make it stockfree?
No. Organic in a title is a slogan. Stockfree rules ban animal and fish by-products. A meal made from blood, bone and fish leftovers fails that rule.
Is Topline the same analysis as Westland 3-9-3?
No. Westland's published 3-9-3 is Westland's bag. Topline's field is 1:0:0. Do not paste one onto the other.
Do animal by-product rules stop me buying an 8 kg garden sack?
No. Category 1 material cannot be fertiliser, and a retail garden pack of 50 kg or less is exempt from the farm mixing-component rule. An 8 kg tub is a garden sack, not a farm mixer.
Will a seaweed bottle always be free of animal inputs?
No. Seaweed is the plant-based option in these listings, and some bottles are still blends. Read the ingredients before you call it vegan.

Related pages

Natural fertiliser buying guide

Natural fertiliser for vegetables

Natural fertiliser

Best natural fertiliser for a stated UK garden job

How to use natural fertiliser: dilute and water in

Sources

Public UK sources from the research digest, used for this page in October 2026. Prices, stars and review counts are from the nine amazon.co.uk listings captured on 19 October 2026. The card score is the star rating multiplied by 20, not a laboratory test. Westland's published fish, blood and bone analysis is an example on the maker's page, not the analysis of every sack here. A dog that eats bone meal needs a vet. This page does not state a poison dose.

  1. RHS, fertilisers (retrieved 19 October 2026)
  2. RHS, seaweed products (retrieved 19 October 2026)
  3. RHS, biostimulants (retrieved 19 October 2026)
  4. RHS, fertiliser labels explained (retrieved 19 October 2026)
  5. RHS, how to feed plants (retrieved 19 October 2026)
  6. GOV.UK, fertiliser from animal by-products (retrieved 19 October 2026)
  7. GOV.UK, organic food approved control bodies (retrieved 19 October 2026)
  8. Soil Association, approved and verified inputs (retrieved 19 October 2026)
  9. Westland, fish, blood and bone (retrieved 19 October 2026)