Surface guide
QR codes on plant tags and garden markers
A garden QR code faces UV, rain, frost and soil splash. Use error correction H, a UV-stable material, and expect to replace printed tags every two seasons unless you use engraved or anodised metal.
View as MarkdownPaste this page into any AI assistant. It is plain, portable Markdown.
| Typical scan distance | 20–40 cm |
|---|---|
| Minimum code width | 2–4 cm |
| Error correction | H |
What actually degrades
| Factor | Effect | Mitigation |
|---|---|---|
| UV | Ink fades, plastic yellows | UV-stable ink and substrate; the code fades before the tag does |
| Rain and soil splash | Obscures the pattern | Mount at 15 cm+ above soil; angle to shed water |
| Frost | Cracks laminate, delaminates labels | Anodised aluminium or engraved plastic |
| Algae and lichen | Reduces contrast | Matt surfaces clean more easily than textured ones |
Materials, by expected life
- Laminated paper: one season. Fine for annual bedding.
- UV-stable vinyl on rigid PVC: 2–3 years.
- Engraved two-colour acrylic: 5+ years, and contrast is structural rather than printed.
- Anodised aluminium (photo-anodised or laser-marked): 10+ years, the standard for botanic gardens.
Specification
- 2–4 cm: visitors lean in, so the distance is short.
- Error correction H, because partial obscuring by leaves and soil is routine.
- Matt finish; a glossy tag in direct sun is unreadable.
- Angle the tag 15–30° from vertical, facing the path. Flat tags collect water and debris; vertical ones are scanned at a steep angle by someone standing.
What to link
A page that survives replanting: the species page, not "the plant in bed 4". Beds get redesigned; species do not.