What's the best seed catalog for comparing seed traits across regions?

If you mean a catalog/database that lets you compare seed or variety traits across different growing regions, the “best” option depends on what crops and regions you care about. A few strong choices:

Best overall for broad comparisons

USDA GRIN-Global / National Plant Germplasm System (NPGS)

• Huge public database of plant germplasm and trait data
• Good for comparing accessions and some region-related performance/metadata
• Best if you want research-grade, cross-region comparison rather than a retail seed catalog

Best for crop performance across locations

Variety trial databases from university extension services

• Often the most useful for comparing yield, maturity, disease resistance, and adaptation by region
• Examples:
  • State university extension variety trials
  • Crop-specific trials for corn, soybean, wheat, tomatoes, etc.
• Best if your goal is “what performs well in my region?”

Best for commercial seed comparisons

Seed catalogs from major breeding companies + independent trial data

• Great for up-to-date commercial hybrids/varieties
• Usually less comparable across regions unless paired with trial results
• Best when you already know the crop and want current offerings

Best for open, searchable trait filtering

Harvard/Genesys PGR or similar germplasm portals

• Useful for searching by traits, origin, and passport data
• Better for breeding/research than home gardening

If you want practical regional gardening comparisons

Seed Savers Exchange + regional extension guides

• Helpful for heirloom and adapted varieties
• Better for climate/region suitability than pure trait comparisons

My recommendation

• For research and trait comparison across regions: USDA GRIN-Global
• For practical “what grows best here?” decisions: university extension variety trials
• For commercial seed shopping: combine seed company catalogs + independent trial data

If you tell me:

1. crop type (vegetables, grains, flowers, etc.), and
2. region/country,

I can point you to the most useful specific catalog or trial database.