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Best hydrangea colourant UK

Updated: October 2026

You want the best hydrangea colourant UK shoppers can actually order from the packs in this comparison, and the articles that praise a nursery tin are ranking a different shelf. On 19 October 2026 the amazon.co.uk set we kept has one named colourant, one feed-and-colourant bundle, one hydrangea feed, and five thin generic listings. Best here means the pack whose listing and reviews are about a colour shift on a responsive pink hydrangea, with a dose you can follow. It does not mean the highest star average. Prices and the full table are on the [blue fertiliser comparison](/hub/fertiliser-soil-and-bark-mulch/blue-fertiliser). We did not lab-test flower colour.

You want the best hydrangea colourant UK shoppers can actually order from the packs in this comparison, and the articles that praise a nursery tin are ranking a different shelf.

Our top picks

Topline Westland hydrangea feed and colourant bundle

Best overall

Topline Westland hydrangea feed and colourant bundle
6.8/10about £16.99
View offer
Vitax Vitax Hydrangea Feed, 1 kg, pack of 2

Preis-Tipp

Vitax Vitax Hydrangea Feed, 1 kg, pack of 2
8.2/10about £11.98
View offer
Westland Westland Hydrangea Colourant, 500 g

Rank 3

Westland Westland Hydrangea Colourant, 500 g
9.1/10about £6.99
View offer
On this page
  1. 1.Best for turning responsive pink flowers blue
  2. 2.When the £16.99 bundle is the one to order
  3. 3.Vitax feed is the best value for flowers, and a different job
  4. 4.Cheap tubs, and why a 5.0 is still a skip

Best for turning responsive pink flowers blue

The top pick for colour in this set is Westland Hydrangea Colourant, 500 g, at £6.99, rated 4.2 out of 5 from 1,244 reviews. The bullets say pale pink hydrangeas go blue and dark pink ones go mauve blue. In the Amazon reviews, buyers who started weekly from spring and watered at the base report pink shrubs moving back towards blue. One late application often shows no change. You buy this tub if the shrub can change and you will keep the powder on the soil from April. Whether your plant can change at all is on the buying guide.

When the £16.99 bundle is the one to order

The Topline bundle at £16.99 is 1 litre of Westland hydrangea liquid feed plus the 500 g colourant, rated 4.5 from 74 reviews. The colourant text repeats the single tub: pink towards blue, darker pink towards mauve blue, or a double rate if the ground is alkaline. Buy it if you want both tins in one parcel. The step up from £6.99 is about £10. Several reviews are too early to judge a flower. A 4.5 from 74 is a cleaner average than 4.2 from 1,244, and the smaller sample is the weaker evidence for colour. If you only need the colourant, the single tub is the buy.
Topline Westland hydrangea feed and colourant bundle

Testsieger

Topline Westland hydrangea feed and colourant bundle
6.8/10about £16.99
View offer

Vitax feed is the best value for flowers, and a different job

Vitax Hydrangea Feed, two 1 kg packs at £11.98, is the best value in this set for feeding a hydrangea: 4.4 out of 5 from 1,741 reviews, magnesium and iron, at planting and as a spring top dressing. Buyers describe larger flower heads and shrubs that bloomed again after a poor year. Some buyers saw flowers move towards blue or blue-purple, and one person who wanted pink objected. According to the product data, aluminium is not stated. A nursery colourant sold under the Vitax name is absent from this amazon.co.uk set. Our Vitax row is the feed. The weekly watering is on how to use hydrangea colourant.

Cheap tubs, and why a 5.0 is still a skip

Five generic listings sit between £3.49 and £6.26. Four have no star line and no review text. The instruction is often sprinkle 30 ml, with no interval and no percentage. The £5.59 pack states aluminium sulphate and shows 5.0 from three ratings with no review sentences. A £6.26 title sits next to the £6.99 named tub and brings no reviews. None of them is the top pick, because value here includes a dose and a history you can read. Compost versus a tub is on hydrangea colourant or ericaceous compost.

Common questions

What is the best hydrangea colourant in this set?
Westland Hydrangea Colourant, 500 g, at £6.99, with 4.2 from 1,244 amazon.co.uk reviews. The listing and the reviews are about pale pink moving towards blue and dark pink towards mauve, when people water the base from spring. It is the top pick because of that match, although 4.2 is a lower average than the bundle's 4.5 from 74 reviews. Crushed tubes and scorch on a small plant are part of the same record.
Should I buy the £16.99 bundle instead of the 500 g tub?
Buy the bundle when you want the colourant and 1 litre of hydrangea liquid feed together. The colourant claim is the same salt story as the £6.99 tub, and the extra money is the feed plus a review set of 74, many of them too early to judge flowers. If the feed will sit in the shed, the single tub is the tighter buy. One reviewer saw brown, crispy growth after using each product once.
Will Vitax feed turn flowers blue?
The listing sells it as hydrangea feed with magnesium and iron. It does not state aluminium, so we do not call it a tested colourant. Some of the 1,741 reviews report a shift towards blue or blue-purple, and one buyer did not want a pink plant to change. If holding pink matters, this is the wrong tin. If you want more flower on an established shrub and can accept a cast of blue, it is the best value feed in the set, at £11.98 for 2 kg.
Why is 5.0 from three ratings not the top pick?
The £5.59 generic pack shows 5.0 from three ratings and no written reviews. Those stars do not describe a flower, a dose or a fault. Westland's 4.2 comes from 1,244 reviews that mention colour, crushed tubes and leaf damage. A large sample you can read outranks a perfect average on an empty comment list. The 109 g pack also prints no percentage.
What should I skip if I want pink to stay pink?
Skip the colourant. Treat the Vitax feed with caution too, because some buyers watched a wanted pink turn blue. A pink bred to stay pink may ignore a salt, and a pink that can shift may not. Lime, which pushes flowers the other way, sits outside this set. Leave blueing salts off a shrub you are trying to hold pink.

Related pages

Blue fertiliser comparison

Blue fertiliser buying guide

How to use hydrangea colourant

Colourant or ericaceous compost

Blue hydrangea in a pot UK: ericaceous compost first

Sources

Public UK and maker sources from the research digest, used for this page in October 2026. Prices, stars and review counts are the amazon.co.uk listings in that digest. The Westland dose and the 93% aluminium sulphate figure are from the manufacturer pages, not from the amazon bullets. A 5.0 from three ratings has no review text.

  1. RHS shrubby hydrangea growing guide (retrieved 22 October 2026)
  2. RHS acidifying soil (retrieved 22 October 2026)
  3. Westland Hydrangea Colourant (retrieved 22 October 2026)
  4. Westland safety data sheet, 8 January 2021 (retrieved 22 October 2026)
  5. BBC Gardeners' World, how to grow hydrangeas (retrieved 22 October 2026)
  6. Grow Scotland, hydrangea flower colour (retrieved 22 October 2026)
  7. Agriculture Act 1970, section 68 (retrieved 22 October 2026)
  8. Fertilisers Regulations 1991, Schedule 2 (retrieved 22 October 2026)