Our Methodology

Trowelful is built and written by Ugo Charles. Here is exactly how the numbers on this site are checked before they publish.

Calculator numbers

Every calculator on Trowelful runs on a shared coverage-math engine (cubic feet, cubic yards, and bag counts from your area and depth). When a guide cites a coverage number, a bag count, or a formula step, it's checked against that same engine's output and against a fixed set of worked-example test cases, so the guide and the calculator never disagree.

Agronomic claims

Claims about plants — days to maturity, planting depth, frost dates, spacing, soil-mix ratios — are checked against primary sources: US university cooperative-extension services and USDA publications. Where a number genuinely varies by region or variety, we say so and give a range instead of a single figure, rather than round it to something that sounds precise but isn't.

Sources

Guides that cite an outside claim link the source at the bottom of the page, under "Sources." If you spot a number that looks off, or a source that's gone stale, let us know and we'll check it.

What we don't do

We don't have a review board or outside editors — Trowelful is a small, one-person site. What we do have is a fixed, repeatable check against the engine and against primary sources every time a page is written or updated, and we'd rather tell you that plainly than imply a bigger team than exists.