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Zone 3A — September

What to Plant in September in Zone 3A

September in Zone 3A: 0 crops to start indoors, 0 to plant or direct sow outside, and 70 entering harvest window. Last frost averages May 22. Reference city: Tower, MN.
Updated August 12, 2026 · Frost data from NOAA 1991-2020 Climate Normals
0 Start Indoors
0 Plant Outside
70 Harvest
Frost risk: Cleared

Frost season has cleared in Zone 3A. The last spring frost typically passed by May 22, and the very latest 10% chance closed by June 7. Tender crops are safe to plant out.

See full Zone 3A frost outlook

Start Indoors in September

Nothing to start seeds indoors in September for Zone 3A.
Next window: February — 2 varieties, including King Richard Leek, Viola and pansy edible flowers.

Plant Outside in September

Nothing to plant or sow outside in September for Zone 3A.
Next window: October — 11 varieties, including Asian Tempest Garlic, Chengdu Garlic, Chesnok Red Garlic.

Harvest in September

Plant Type Planted / Sown Harvest Window
Burgess Buttercup Winter Squash squash May 29 Sep 1
Indian Spring Mix Hollyhock Flowers flower May 22 Sep 19 – Nov 18
Mammoth Sandwich Island Salsify root vegetable May 29 Sep 26
Southport Red Globe Onions allium May 22 Sep 19
Southport White Globe Onions allium May 22 Sep 19
Spanish Sweet White Onions allium May 22 Sep 9 – Sep 19
Summer Carnival Mix Hollyhock Flowers flower May 22 Sep 19 – Nov 18
Adirondack Blue Potato (fall planting) root vegetable Jun 25 Sep 20
All Season Cabbage (fall planting) brassica Jun 25 Sep 13
All Sweet Watermelon melon Jun 5 Sep 3 – Sep 8
All Year Round Lettuce (fall planting) lettuce Jun 25 Sep 6
Amarillo Oro Melon melon Jun 5 Sep 3
Angelica (fall planting) herb Jun 25 Sep 23
Baby Blue Eyes Flowers (fall planting) flower Jun 25 Sep 23
Bachelor's button edible flowers (fall planting) flower Jun 25 Sep 13
Banana Melon melon Jun 5 Sep 3
Black Diamond Watermelon melon Jun 5 Sep 3
Broad Windsor Fava Bean (fall planting) legume Jun 25 Sep 13
Broadleaf Full Heart Batavian Endive (fall planting) lettuce Jun 25 Sep 23
Brunswick Cabbage (fall planting) brassica Jun 25 Sep 23
Charleston Wakefield Cabbage (fall planting) brassica Jun 25 Sep 3
Chinese Broccoli (Gai Lan) (fall planting) brassica Jun 25 Sep 3
Congo Watermelon melon Jun 5 Sep 3 – Sep 8
Cosmic Purple Carrot (fall planting) root vegetable Jun 25 Sep 8
Crimson Clover (fall planting) cover crop Jun 25 Sep 23
Crisphead Lettuce (fall planting) lettuce Jun 25 Sep 8
Danvers Carrot (fall planting) root vegetable Jun 25 Sep 13
Dark Green Romaine Lettuce (fall planting) lettuce Jun 25 Sep 3
Early Jersey Wakefield Cabbage (fall planting) brassica Jun 25 Sep 8
Evergreen Parsley (fall planting) herb Jun 25 Sep 18
Georgia Rattlesnake Watermelon melon Jun 5 Sep 3 – Sep 8
Georgia Southern Collard Greens (fall planting) lettuce Jun 25 Sep 18
Globe Gilia Flowers (fall planting) flower Jun 25 Sep 13
Glory of Enkhuizen Cabbage (fall planting) brassica Jun 25 Sep 23
Green Arrow Pea (fall planting) legume Jun 25 Sep 3
Hairy vetch cover crop stands (fall planting) cover crop Jun 25 Sep 23
Iceberg Lettuce (fall planting) lettuce Jun 25 Sep 8
Igloo Cauliflower (fall planting) brassica Jun 25 Sep 3
Jubilee Watermelon melon Jun 5 Sep 3 – Sep 8
King Richard Leek (fall planting) allium Jun 25 Sep 8
Love-in-a-Mist Flowers (fall planting) flower Jun 25 Sep 3
Mammoth Melting Sugar Snow Pea (fall planting) legume Jun 25 Sep 8
Medium Red Clover Cover Crop (fall planting) cover crop Jun 25 Sep 8
Michihili Cabbage (fall planting) brassica Jun 25 Sep 3
Morris Heading Collard (fall planting) lettuce Jun 25 Sep 13
Mâche (Corn Salad) (fall planting) lettuce Jun 25 Sep 17
Nantes Carrot (fall planting) root vegetable Jun 29 Sep 12
Napa Cabbage (fall planting) brassica Jun 25 Sep 3
Nodding Catchfly Flowers (fall planting) flower Jun 25 Sep 23
Oregon Sugar Pod Snow Pea (fall planting) legume Jun 25 Sep 1
Orion Florence Fennel (fall planting) vegetable Jun 25 Sep 13
Queen Anne's Lace Flowers (fall planting) flower Jun 25 Sep 8
Radicchio (fall planting) lettuce Jun 25 Sep 18
Rapeseed Cover Crop (fall planting) cover crop Jun 25 Sep 3
Red Acre Cabbage (fall planting) brassica Jun 25 Sep 13
Red Romaine Lettuce (fall planting) lettuce Jun 25 Sep 3
Romaine Lettuce (fall planting) lettuce Jun 25 Sep 8
Scarlet Flax Flowers (fall planting) flower Jun 25 Sep 3
Shelling Pea (fall planting) legume Jun 25 Sep 3
Snow Pea (fall planting) legume Jun 25 Sep 3
Tendersweet Orange Watermelon melon Jun 5 Sep 3 – Sep 8
Tom Thumb Lettuce (fall planting) lettuce Jun 25 Sep 3
Tuscany Black Kale (fall planting) lettuce Jun 25 Sep 8
Vates Collard (fall planting) lettuce Jun 25 Sep 8
Verona Red Chicory (fall planting) lettuce Jun 25 Sep 25
Viola and pansy edible flowers (fall planting) flower Jun 25 Sep 3
Waltham 29 Broccoli (fall planting) brassica Jun 25 Sep 23
Wando Pea (fall planting) legume Jun 25 Sep 1
Yukon Gold Potato (fall planting) root vegetable Jun 25 Sep 23
Sugar Snap Pea (fall planting) legume Jul 13 Sep 21

Key Tasks for September in Zone 3A

  1. 1 Check soil moisture before watering — stick a finger 2 inches into the soil. Water only when the soil is dry at that depth. Consistent moisture is more important than frequency.
Back to full Zone 3A planting calendar
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