Zone 6 - Complete Planting Calendar & Checklist

Zone 6 - Complete Planting Calendar & Checklist

Zone 6  |  -10F to 0F

Excellent all-around growing season. Chicago is now Zone 6a in the 2023 map — a significant change from its old Zone 5b classification. Most of Chicagoland shifted to 6a, with lakeside neighborhoods like Lincoln Park reaching 6b. Two cool-season windows (spring and fall) make this one of the most versatile zones.

 

  • Zone 6 has average annual extreme minimum temps of -5°F to 0°F
  • The growing season runs approximately 155–165 days (mid-May to mid-October)
  • Lake Michigan moderates temperatures in lakeside neighborhoods (Zone 6b/7a border near the lake)
  • Inland western suburbs may experience harder frosts – know your microclimate!
  • Chicago's extreme weather demands flexibility: always have row cover on hand

Dates & Season

  • Temp range: -10F to 0F
  • Last spring frost: Mar 30 - Apr 30
  • First fall frost: Oct 15 - Nov 5
  • Growing season: 165-200 days

Month-by-Month Planting Calendar

Use this calendar as your primary guide. Dates are based on the Chicago area's average last frost of May 10 and first frost of October 15.

Month

Start Indoors

Plant / Sow Outdoors

Key Tasks

January

 Start onions late Jan (14 wks before Apr 15)

Order seeds

• Nothing yet – ground frozen

Start onion seeds late January under lights

Order seeds — best selection available now

Plan layout and crop rotation

Check cold frames and hoop houses
• Test soil pH from samples

February

Peppers (8-10 wks — Feb 14 for Apr 25 transplant)

Eggplant, leeks

Nothing — last frost approximately April 15.

Start peppers/eggplant under lights

Order bare-root trees and shrubs

Prune dormant fruit trees on mild days

Apply dormant oil spray before bud break

March

Tomatoes (mid-Mar — 6-8 wks)

Broccoli, cabbage (late Mar — 5-6 wks)

Celery

• Celeriac

• Peas (late Mar – soil workable)

Spinach, kale, arugula under row cover.

• Direct sow peas when soil reaches 40F

• Apply dormant oil spray to fruit trees

Prepare beds — add compost, test pH

Prune fruit trees and canes

April

• Cucumbers (late Apr)

• Squash (late Apr)

• Melons (late Apr)

• Basil

 

• Carrots

• Beets

• Lettuce

• Spinach

• Radishes

• Kale

• Swiss chard

• Broccoli transplants

 

Transplant cool-season crops outdoors

 Direct sow root crops and greens

• Harden off warm-season transplants 7-10 days

• Prep irrigation system

May

• Nothing new – focus on transplanting

After May 10 (last frost) transplant tomatoes, peppers

• Direct sow eggplant, beans, corn, cucumbers, squash, melons, basil

• Plant sweet potato slips late May

• Transplant all warm-season crops after last frost

• Mulch beds 2-3 in.

• Set up drip irrigation

• Plant sweet potato slips and warm herbs

June

• Nothing

Succession: beans (every 2-3 wks), cucumbers, carrots (2nd sowing), beets.

• Fertilize heavy feeders every 2-3 weeks

• Monitor for squash vine borer, flea beetles, aphids

• Water 1 in./week

• Cage and stake tomatoes

July

Start fall broccoli/cabbage/kale (mid-July — for Aug transplant).

Succession beans

Direct sow fall brassicas outdoors (late July).

• Deep water in heat

• Side-dress heavy feeders with compost

• Harvest daily to keep plants productive

• Pinch back basil to prevent bolting

August

• Nothing

Aug 1-15: transplant fall brassica starts

Direct sow: spinach, arugula, kale, radishes, turnips, cilantro.

• Transplant fall brassicas by Aug 15 — second season!

• Sow fall greens

• Prep garlic bed

• Harvest and preserve summer crops

September

• Nothing

Garlic (Sep 15 - Oct 15)

Cover crops (winter rye, clover).

• Plant garlic Sep 15 - Oct 15

• Sow cover crops in cleared beds

• Use row cover to extend season

• Harvest winter squash

October

• Nothing

Spring bulbs after first frost.

• First frost Oct 15 - Nov 1

• Harvest before frost

• Mulch garlic 4-6 in.

• Plant spring bulbs

• Compost healthy plant debris

November

• Nothing

Garlic (early Nov if ground still workable).

• Winterize irrigation

• Mulch perennials 4-6 in.

• Store tools cleaned and oiled

• Review season notes

December

• Nothing

• Nothing

• Order seeds (January for best selection)

• Plan next season

• Crop rotation planning

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