Growing collards in zone 7a

Evidence trail

How these dates are built

Sprout applies the cited planting offsets to the typical zone 7a frost anchors. The result is a planning baseline for the zone, not a local weather forecast.

• USDA Plant Hardiness Zone Map, 2023USDA Agricultural Research Service / Oregon State University PRISM Group. Supports the USDA hardiness-zone band.
• U.S. Climate Normals 1991-2020NOAA National Centers for Environmental Information. Supports the median spring and fall freeze dates.
• Collards (HGIC 1307)Clemson Cooperative Extension, Home & Garden Information Center. Supports days to maturity (direct).
  Method note

  Spacing 6-18 inches in rows 18-36 inches (lower bounds stored), seed depth 1/4 to 1/2 inch (lower bound stored), soil pH 6.0-6.5 (Cornell gives 6.0-7.5; Clemson's dedicated factsheet is used), days to harvest 60-80 from direct seeding, pest and disease list. Clemson's planting dates are South Carolina calendar tables, so frost-relative windows come from Cornell.

• Vegetable Growing Guides: CollardsCornell University Home Gardening. Supports indoor seed-starting timing (direct), outdoor transplant timing (derived), direct-sowing timing (direct), and fall direct-sowing timing (normalized).
  Method note

  Full sun. Spring windows: start inside about 8 weeks before last frost, transplant at about 6 weeks old (re-expressed as transplant 2 weeks before last frost), direct seed 3 weeks before last frost. Fall window: direct seed about three months before expected fall frost, converted to about 13 weeks.

Keep planning

Put these dates to work

The plant profile covers spacing, light, water, soil, and source-backed timing details. The growing guide covers preparation, care, and harvest technique.