Sources
Arithmetic needs no authority; guidance does. These six pages are what the practical advice on this site draws on, and anything not attributed to one of them is our own sequencing rather than a cited claim.
What is cited, and what is not
Arithmetic needs no authority: area, volume, bag counts and roll counts are sums you can repeat by hand, and the calculation methodology writes them out. Practical horticultural guidance is different, and everything on this site that falls into that category is attributed below to a page that was read and dated.
Anything not attributed to one of these six pages is this site's own practical sequencing — the order of steps in the levelling method, for instance, or the month classification the lawn care planner uses. Those are labelled as ours where they appear.
RHS — Lawn Care in Autumn
Open this page on the publisher's site
https://www.rhs.org.uk/lawns/autumn-care
What this site relies on it for
- The mild, damp conditions of early autumn suit this maintenance, and the key tasks are best done in September or October — though not all of them are needed every year.
- Raking or scarifying removes thatch, which helps water reach the soil and improves air circulation between the grass plants.
- The field test: if you cannot see the soil between the blades of grass, the lawn would benefit from scarifying.
- Rake vigorously with a spring-tined rake, aiming to reduce loose debris without uprooting the grass, then compost what comes out.
- Aerating improves the movement of air and water among the grass roots. Spike with a garden fork, holes 10–15cm apart, as deep as the tines will go, working the fork back and forth to enlarge them.
- On a large lawn, concentrate on the most worn or compacted areas, or aerate a different area each autumn.
- For most lawns aerating every two to three years is adequate; on clay or waterlogged soil a hollow-tined aerator is better, every three to four years.
- Top-dressing is the next step after aerating: six parts sharp sand, three parts loam and one part well-rotted compost or soil improver, raked into the holes. It is particularly useful on heavy soil.
Where it is used
RHS — Lawn Care in Spring and Summer
Open this page on the publisher's site
https://www.rhs.org.uk/lawns/spring-summer-care
What this site relies on it for
- Spring is a good time to rake moss out of a lawn and add it to the compost heap.
- A sparse lawn can be overseeded in mid-spring once the weather is milder, although early autumn remains the ideal time.
- Established lawns recover once rainfall returns, so watering through a dry spell is generally not necessary.
Where it is used
RHS — How to Lay Turf
Open this page on the publisher's site
https://www.rhs.org.uk/lawns/lawns-from-turf
What this site relies on it for
- Complete the site preparation well before buying or having the turf delivered.
- Get rid of perennial weeds such as couch grass and bindweed first, forking out the roots.
- Dig or rotovate the soil to a depth of 20–25cm so there is no compaction.
- Incorporate plenty of well-rotted manure or other organic matter, especially on sandy soil — and only well-rotted material, because undecomposed matter shrinks and makes the surface sink unevenly.
- Measure the area and check the dimensions of the turf pieces carefully before buying.
- Lay turf within 24 hours of delivery if possible; if laying is delayed more than a few days, unroll it flat and water it if dry.
- Stand on boards to avoid making footprints, stagger the joints like bricks in a wall, and push the pieces together tightly.
- Turf is best laid in mid-autumn and can be laid from mid-autumn to early spring whenever the soil is not too wet or frosty; laying from mid-spring to early autumn is best avoided.
Where it is used
RHS — Mulches and Mulching
Open this page on the publisher's site
https://www.rhs.org.uk/soil-composts-mulches/mulch
What this site relies on it for
- To be effective, biodegradable mulches need to be between at least 5cm and ideally 7.5cm thick.
- Take care not to pile mulch up against the stems of woody plants.
- Lay mulches over moist soil, after removing weeds, when the soil is not frozen.
- Single trees and specimen shrubs are best mulched to the radius of the canopy.
- Mulches are best applied from mid- to late spring and in autumn, and around new plantings at any time of year.
Where it is used
RHS — Organic Matter: How to Use in the Garden
Open this page on the publisher's site
https://www.rhs.org.uk/soil-composts-mulches/organic-matter-how-to-use-in-garden
What this site relies on it for
- To improve soil it is usual to apply about 5–10kg per square metre.
- For weed control as a mulch, or as a surface application in no-dig gardening, at least 5cm is required, which amounts to about 50 litres per square metre.
- In practice it is easier and more effective to apply 8cm, which needs about 50% more organic matter.
- Check quantities by weight where you can, because wet manures and composts are much heavier than drier materials.
- Only use well-rotted material when digging it in, to avoid depleting nitrogen from the soil.
- The coarser the material, the longer it takes to break down.
Where it is used
TurfOnline — Jubilee Lawn Turf (roll dimensions)
Open this page on the publisher's site
https://www.turfonline.co.uk/product/jubilee-lawn-turf/
What this site relies on it for
- One product page states that each roll measures 610mm wide by 1,640mm long and covers 1m².
Where it is used
Not cited
One further page was attempted during research and could not be read, so nothing on this site draws on it. It is recorded here because a source register that only lists successes is not a complete account of what was looked at.
- Rolawn — Calculating topsoil requirements. Requested on 6 August 2026 and returned an access-denied response, so nothing on this site draws on it. No figure from it has been used, paraphrased or assumed.
https://www.rolawn.co.uk/information-advice/topsoil/choosing-topsoil/calculating-requirements/
How these citations work
- Dates are stated as checked and nothing else. We do not know when a publisher last revised a page, so we do not claim to.
- No publisher listed here endorses this site, is affiliated with it, or has reviewed it. They are pages that were read; nothing more is implied.
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Links are ordinary navigation, carry
rel="noopener", have no tracking parameters and go directly to the publisher rather than through a redirect. Following one takes you to another organisation's site under their terms. - Where our arithmetic and a source's rule of thumb differ, both are shown and the difference is stated — the compost calculator's note about 8 cm needing 60% more material rather than "about 50% more" is the worked example of that policy.