January · USDA Zone 6
winterWhat to plant in January in USDA zone 6
Winter planting guide for zone 6 (Southern Pennsylvania, Ohio, Missouri, parts of mid-Atlantic) — a 180-day growing season with last frost around mid- to late April and first frost around mid- to late October.
Sow indoors in January — zone 6
Start these seeds under lights or in a heated propagator so transplants are ready when the outdoor planting window opens.
- Onions and leeks — Late January under 14-16 hours of light.
- Slow-growing perennial herbs — Rosemary and lavender from seed take 8-10 weeks.
Harvest in January — zone 6
These crops should be ready or in active harvest in January for zone 6 gardens. Pick fruiting crops every 2-3 days to keep production going.
- Overwintered kale, leeks, and parsnips — Cold sweetens them — pull as needed.
Prep and planning — zone 6
- Dormant pruning
Universal January tasks
These apply across most US and UK gardens in January, regardless of zone.
- Order seeds for the spring garden — popular varieties sell out by February.
- Sketch a garden plan and rotate crop families away from where they grew last year.
- Clean, sharpen, and oil pruners, loppers, and shovels before spring.
- Inspect overwintered garlic, perennial herbs, and mulch — top up where exposed.
- Set up seed-starting lights and check that timers and heat mats still work.
- Prune dormant fruit trees and grapes on a mild, dry day.
Why this works for zone 6
Zone 6 has average annual minimum temperatures of -10 to 0°F (-23 to -18°C) and a frost-free window from mid- to late April to mid- to late October — about 180 growing days. Two-season growing — cool-season crops in spring/fall, warm-season in summer. Heirloom tomato varieties work well here.
Dates are zone-wide averages. Local microclimates (south-facing slopes, urban heat, lakeside warmth, elevation) can shift the window by 1-2 weeks within the same zone.
UK gardeners — January
Across the UK, January is the planning month. Sow onions, leeks, and broad beans under cover from late January in milder southern gardens. RHS H4-H5 zones should keep overwintered kale, leeks, and parsnips harvested and mulched.
Source and methodology
Frost-date averages from NOAA Climate Data Online within USDA zone 6. Hardiness boundaries from the USDA Plant Hardiness Zone Map (2023). Crop timing curated against US Cooperative Extension Service publications (UNL, UMN, NC State, Texas A&M, UF/IFAS, Oregon State) and cross-referenced against the RHS sowing calendar. Curated by the Growli editorial team.
Keep going
- ← December in zone 6
- February in zone 6 →
- All zones — what to plant in January
- USDA Zone 6 — frost dates and crop list
- Full 12-month planting calendar