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Lawn lime or sulphur

Updated: October 2026

A yellow lawn and two products on the shed shelf can look like the same job. Lawn lime or sulphur is the opposite choice: lime raises pH, sulphur lowers it, and chalk that fizzes is the wrong job for both. This page is from Peter F., the DIY & tools editor, on 21 October 2026. He used Royal Horticultural Society pages on lime, pH, acidifying and chalk, plus the seven amazon.co.uk listings on the [lawn lime comparison](/hub/fertiliser-soil-and-bark-mulch/lawn-lime). A qualifying Amazon purchase can earn us a commission at no extra cost to you. There is no sulphur ASIN in this set, and this page can tell you to buy none of the lime bags.

A yellow lawn and two products on the shed shelf can look like the same job. Lawn lime or sulphur is the opposite choice: lime raises pH, sulphur lowers it, and chalk that fizzes is the wrong job for both.

Our top picks

Topline Topline garden lime and Epsom salt

Best overall

Topline Topline garden lime and Epsom salt
3.5/10about £18.95
View offer
Westland Westland Lime Soil Conditioner (pack of 2)

Rank 2

Westland Westland Lime Soil Conditioner (pack of 2)
8.2/10about £19.98
View offer
MURIEL BARGAINS Levington Garden Lime 3.5 kg

Best value

MURIEL BARGAINS Levington Garden Lime 3.5 kg
4.0/10about £11.49
View offer
On this page
  1. 1.Lime raises pH and sulphur lowers it
  2. 2.Test pH, and check for chalk with vinegar
  3. 3.When lawn lime is the wrong shopping list
  4. 4.When sulphur will not fix chalk

Lime raises pH and sulphur lowers it

Garden lime is calcium carbonate. It makes acid soil less acid. It does not cancel a sulphur dressing. Sulphur is the acidifier: soil organisms turn it into sulphuric acid, and dust works faster than chips. The RHS figures for the top 15 cm, from about pH 7.0 or 7.5 toward 6.0–6.5, are 135 g of sulphur powder per square metre on sand and up to 270 g on clay. Those grams are for a bed, not a lawn sprinkle. Surface sulphur can take years. Epsom salt does not lower pH, and ferrous sulphate is not a lasting acidifier. If the test is acid and you want carbonate, start with the lawn lime buying guide.

Test pH, and check for chalk with vinegar

Use a kit outside the three months after lime, fertiliser, or organic matter. The RHS treats about pH 6.5 as the general-purpose figure, usually adds nothing at pH 6.1–7.0, and says not to lime at 7.0 or higher. Put vinegar on dry soil. If it fizzes, free carbonate is present. Acid soil and a non-ericaceous lawn can move toward a carbonate bag. Around 6.5, buy nothing. Alkaline soil, or a fizz, means buy none of the seven lime listings. GreenBest's note, lime below pH 6.5 and sulphur at pH 8 or above, is their system, not an RHS rate, and no listing here is that sulphur. A ryegrass lawn at pH 7.2 is not a lime customer. A fine lawn at 5.6 is not a sulphur customer. Moss causes stay on lawn lime for moss.
Topline Topline garden lime and Epsom salt

Testsieger

Topline Topline garden lime and Epsom salt
3.5/10about £18.95
View offer

When lawn lime is the wrong shopping list

At pH 7.0 or higher, every listing in this comparison is the wrong buy. The same stop applies if vinegar fizzes. Chalky soils sit around pH 7.1–8.0 on the RHS chalk page. Do not import clubroot plot rates onto turf. Yellow leaves on chalk are often iron and manganese locked by the high pH, and more carbonate makes that worse. The seven amazon.co.uk rows are lime or lime plus Epsom. None of them lowers pH. If you already know you need carbonate, take the seller-name and weight check to best lawn lime.

When sulphur will not fix chalk

If vinegar fizzes, the soil cannot realistically be acidified. The RHS chalk page says huge quantities of sulphur would be needed for years. Choose plants that tolerate lime, or grow ericaceous plants in containers. The 135–270 g figures are for the top 15 cm, dug in, not a lawn dressing. Surface sulphur can take years. This comparison has no pet or child safety claim for sulphur. GreenBest's little-and-often note at pH 8 or above is their scorch warning, not a rate for another sulphur. At pH 5.5, sulphur is the wrong product. At 7.2 with no fizz, sulphur might be discussable for a bed, still dug in, not sprinkled on a family lawn. If there is fizz, buy neither.

Common questions

Does lime raise pH or lower it?
Lime raises pH. Calcium carbonate makes acid soil less acid. It is the wrong bag when the kit is already 7.0 or higher, or when the soil fizzes. It is not a fertiliser, and it does not cancel sulphur.
What does sulphur do to soil pH?
Sulphur lowers pH. Soil organisms turn it into sulphuric acid. Dust is quicker than chips, and cold soil can mean months. It will not acidify chalk that fizzes, and the RHS incorporated rates are a bed figure, not a lawn sprinkle.
My soil fizzes with vinegar. Can I still lime, or still use sulphur?
Neither is a realistic fix. Fizz means free carbonate. Lime adds more of the same chemistry. Sulphur cannot keep up with that reserve. Grow lime-tolerant plants, or put ericaceous plants in containers.
The kit says pH 7.2. Should I buy a bag from this comparison?
No. The RHS says not to lime at pH 7.0 or higher. All seven listings are lime or lime plus Epsom. A 7.2 reading is a reason to leave this comparison, not to pick a cheaper bag.
The kit says pH 5.5. Is sulphur the wrong product?
Yes. 5.5 is already acid. Sulphur would push it further. Whether you then buy lime depends on the grass: a ryegrass family lawn may want a higher pH; a fine lawn near 5.5 is not an automatic limestone order.
How much sulphur lowers a lawn, and can I leave it on the surface?
The RHS 135–270 g per square metre figures are for digging into the top 15 cm of a bed, sand to clay, from about pH 7–7.5 toward 6–6.5. Surface sulphur can take years. This page will not offer those grams as a weekend lawn dressing, and it has no pet-safety claim for sulphur.
I want blueberries or rhododendrons in this soil. Will lime help?
No. Those plants want acid soil. Lime moves the pH the wrong way. On chalk that fizzes, sulphur is not a realistic rescue either. Use ericaceous compost in containers, or choose plants that tolerate lime.

Related pages

How to apply lawn lime

Lawn lime

Best lawn lime: seller, weight and a UK review file

Lawn lime buying guide: test the soil before you buy

Lawn lime for moss: only after the soil tests acid

Sources

Public UK and maker sources from the research digest, used for this page in October 2026. Prices, stars and review counts are from the seven amazon.co.uk listings captured on 19 October 2026. A moss line is a listing claim. A maker's pet line applies to that garden lime, not to hydrated lime or to every bag. This is not a laboratory test.

  1. RHS, lime and liming (retrieved 19 October 2026)
  2. RHS, soil pH and testing (retrieved 19 October 2026)
  3. RHS, moss on lawns (retrieved 19 October 2026)
  4. RHS, acidifying soil (retrieved 19 October 2026)
  5. Westland Garden Lime (retrieved 19 October 2026)
  6. Levington Lime (retrieved 19 October 2026)
  7. Fertilisers Regulations 1991 (retrieved 19 October 2026)
  8. CAFRE, the value of lime (retrieved 19 October 2026)