Methodology

What this is

A free, openly-accessible plant database covering 1,972 varieties across 30 categories, with zone-specific planting calendars, companion-planting data, nutrition data, and growing guides. Maintained by Brian L of Wind River Greens, a small microgreens farm in Milton, Georgia.

The database combines structured data sourced from authoritative third parties (extension services, USDA, breeder catalogs) with editorial narrative (growing guides, troubleshooting, companion guides) composed from those real source materials. The "editorial process" section below explains exactly which content is computed from data and which is composed from sources.

Data sources

Variety identity (name, scientific name), growing characteristics (zones, sun, soil, height), and other structured fields come from four authoritative sources. Where a variety appears in multiple sources, the data is reconciled in favor of the more cultivar-specific reference. Source attribution is shown on each variety page under the "Sources & References" section.

Coverage: 1,822 of 1,972 varieties (92%) have at least one external citation. The remainder are typically niche ornamentals or houseplants not yet present in these public datasets.

How planting calendars are calculated

Planting calendars are computed deterministically from real data, not freeform-generated. For each variety + USDA hardiness zone combination, the calendar is computed from:

• NOAA frost-date data per USDA zone (average last spring frost, average first fall frost)
• Variety days-to-maturity from the breeder source (typically Johnny's)
• Crop classification (warm-season / cool-season / perennial / indoor-only) determining sow-window logic

Indoor-only categories (houseplant, succulent) are correctly excluded from the calendar — they have no seasonal planting window. The current dataset includes 0 varieties with calendar entries spanning USDA zones 1–13.

Editorial synthesis from sources

Long-form narrative on each variety page is editorially composed from the variety's real source data — its NC State Extension pest and disease records, its companion-plant research records, its real zone range and days-to-maturity. The process is designed to ground every narrative section in verified facts and to screen out generic boilerplate.

Sections composed from source data

• Troubleshooting (symptom → causes → fixes) — composed from the variety's real pest/disease data from NC State Extension
• Companion guide prose — composed from the variety's real companion-plant records in our research database
• Succession guide — composed from the variety's actual zone range and days-to-maturity
• Growing guide narrative (long-form) — composed from NC State Extension content where available, otherwise from structured field data

Quality gate

1. Initial draft composed from the variety's real source data (pests, diseases, zones, days-to-maturity)
2. Self-critique pass: the draft is reviewed for banned phrases, vague abstractions, and generic cadence, then rewritten
3. Automated audit against a 47-phrase banned-language list ("tapestry," "delve," "navigate," etc.)
4. Audit-flagged outliers are regenerated under a stricter editorial pass

Verified, not synthesized

• Variety identity (name, scientific name, taxonomy)
• USDA hardiness zone ranges
• Planting calendar dates (NOAA frost + days-to-maturity formula)
• Nutrition data (USDA FoodData Central)
• Companion plant identities (sourced from research; only the prose around them is composed)
• Source URLs (curated from real attribution)

Limitations

• Days-to-harvest is an estimate. Real-world outcomes vary with local microclimate, weather year-to-year, soil, and seed source.
• Zone ranges are guidance, not guarantees. Zone 7b in coastal Georgia and zone 7b in interior New Mexico are different growing conditions in practice.
• This is a reference, not professional advice. For plant pathology, agricultural decisions, or commercial growing, consult your state extension service.
• Composed narrative sections can contain errors. Despite source-grounding and editorial audit, mistakes are possible. If you notice an error, please report it.
• Variety data was last refreshed in late April 2026. Future updates will be noted in the source-file timestamps.

Updates & corrections

Source data is refreshed periodically as the underlying datasets (NC State Extension, Johnny's, USDA FoodData Central) update. Each variety page shows a dateModified in its page metadata reflecting the most recent edit to that record.

Spot an error? Email info@windrivergreens.com with the variety name and the issue. Corrections are typically applied within a week.