The Planters' Guild
Sources & Methods
How we know what we tell you, and what we do when we get it wrong.
Most gardening advice online gets written from memory, copied from other advice that was written from memory, and lately churned out by machines that have read all of it and can't tell the true parts from the wrong ones. That bothered us enough to start The Planters' Guild, so it seems only fair to tell you how our own pages get made. Short version: if we say something about how a plant actually works, there's a published source under it, and we show you what it is.
Where our facts come from
Not every source deserves the same trust. We work down a ladder and grab the highest rung we can actually stand on.
- Peer-reviewed research. The primary literature, where a claim has already survived other scientists trying to poke holes in it. That's our first stop for anything about plant physiology, substrate physics, or pests.
- Standards and government science. Bodies like the U.S. Geological Survey (USGS) and U.S. Department of Agriculture (USDA), and the international standards groups, for measured numbers that somebody has actually published.
- Extension services and botanical institutions. The horticultural research programs and botanic gardens whose whole job is turning that science into something a grower can use.
- Named industry sources. We use these sparingly, only when a company is the honest origin of a fact (how a material actually gets processed, say), and we always label it as such.
When two rungs disagree, the higher one wins, and we tell you so in the text.
How we cite
Every article that makes factual claims carries a Sources block in APA 7 format (the citation style used across the sciences), and wherever a source is free to read we hyperlink it so you can go check it yourself instead of taking our word. Opinion pieces and first-person field notes get labeled as what they are, and we hold them to a different bar. A story about our own potting bench isn't a claim about botany.
How we check ourselves
Before a research-heavy piece goes live, we verify its citations against the original publications one at a time: the right authors, the right journal, the right year, and a claim the paper actually makes. It's tedious, and it catches things. It has caught us. One was a citation pointing at a paper that didn't exist; another was an author's name grafted onto the wrong study. When we find one, we fix the live page and note the change. We'd rather correct our record in public than keep a tidy one.
We treat our own published pages as correctable, not finished. If the evidence moves, or we just got it wrong, the page changes.
When the evidence is thin
A lot of popular plant lore lives somewhere between true, harmless, and quietly wrong. Eggshells for calcium, Epsom salt for everything, a layer of rocks for drainage. When we take one of these on, we tell you where the evidence actually lands, and sometimes that's an honest "it depends" or "nobody has really measured this." We don't dress folklore up as fact, and we don't knock something down just to sound clever. We want you walking away able to decide on real information.
A note on measurements
We lead with imperial units and put metric in parentheses, because most of our readers garden in inches and gallons. Where a field works in metric by convention, we go with the field.
Written by people
People research, write, and edit our articles. We use software the way any writer does now, but a person picks every source, checks every number, and signs off on every page. The judgment is human, and so is the responsibility.
Found a mistake?
Tell us. If you can point to a source that corrects something we've published, that's about the most useful email we can get, and we'll thank you by fixing it. Reach us here.