What published sources say about houseplant light: 543 figures transcribed from 80 publishers

543 published figures and statements about the conditions houseplants are given indoors — light, humidity, temperature and airflow — transcribed one at a time from 80 publishers. 347 of the rows come from .edu domains: university extension services at Arizona, Illinois, Penn State, Clemson, Iowa State, Mississippi State, Purdue, NC State, UConn, UF/IFAS and others, alongside botanical gardens, a veterinary school, a poison-control centre, a national laboratory and peer-reviewed work.

Units are left exactly as each source writes them and nothing is converted: a source that publishes foot-candles stays in foot-candles, one that publishes lux stays in lux. Every row carries the URL it was read on and the date it was read.

The value of the collection is that the sources disagree, and the disagreements are invisible if you only read one of them. Two extension services put a ZZ plant's cold limit at 60 F and 50 F. Two put a peace lily's at 60 F and 40 F. Where a low-light band starts is given as 25, 75 and 100 foot-candles by three different services. Humidity advice runs from 40-50 per cent to 70-80 per cent. A north windowsill is given as 200 ft-c by one and 75 foot-candles by another.

What it is not: a survey of the literature. The rows were collected because the pages on growspotapp.com needed them, so coverage follows those questions rather than a sampling frame. There is no weighting, no quality score and no attempt to reconcile anything — two rows that contradict each other both stay. It is also not our own measurement; those are published separately as indoor light-meter readings.

Licence: the compilation is CC BY 4.0 — which sources were read, how the rows are structured, and the links. The quoted sentences are not ours to license: each remains the property of the publisher named in its row, reproduced as a short excerpt for identification with the link kept. If you republish the file, keep the source_url column with it.

Columns: publisher, source_url, appears_on, subject, value_as_published, quote, read_on. value_as_published is a string rather than a number, because "800-2,000+ lux" and "four or more hours of direct sun" are both answers people publish. Same data in CSV and JSON.