How we know

Every crop claim on BioArva is meant to resolve to a source, date, geography, and applicability note. We do not blend one “tomato fact.” Numbers without a registry row stay qualitative or are omitted.

Growing guidance is general information. Symptom pages list common possibilities — not a confirmed diagnosis. Soil-test output is educational context, not a treatment recommendation.

Frost reference

The Field Book frost block is NOAA/NCEI U.S. Climate Normals 1991–2020, by station, at 32 °F. A ZIP is mapped to a ZCTA centroid; the nearest station with all seven 32 °F fields complete is shown if it is within 40 miles, labeled distant from 40 to 75 miles, and omitted beyond 75 miles. Primary radius 40 miles; fallback 75 miles. Measured coverage on the 2025 ZCTA gazetteer: 96.99% of centroids within 40 miles of an eligible station, 98.97% within 75 miles. No interpolation, no plant/don’t-plant state.

Data version: Normals v1.0.1, archive dated 2023-04-04, retrieved 2026-09-03, from the NCEI by-station archive us-climate-normals_1991-2020_v1.0.1_annualseasonal_multivariate_by-station_c20230404.tar.gz.

Screen wording follows NCEI, Normals Calculation Methodology 2020 (Normals_Calculation_Methodology_2020.pdf), section “Frost-Freeze Probability Dates,” page 26 of 32: “Frost-freeze probability dates represent the likelihood that a given minimum temperature will be experienced before or after a given date. Probability dates are provided for the beginning of the growing season (i.e., the probability that the last spring freeze will occur on or after the specified date) and the end of the growing season (i.e., the probability that the first autumn freeze will occur on or before the specified date).” Growing-season length: “the likelihood that the growing season … will be at least the specified number of days.” https://www.ncei.noaa.gov/data/normals-annualseasonal/1991-2020/doc/