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Zone 4A — September

What to Plant in September in Zone 4A

September in Zone 4A: 0 crops to start indoors, 0 to plant or direct sow outside, and 118 entering harvest window. Last frost averages May 14. Reference city: Fargo, ND.
Updated August 12, 2026 · Frost data from NOAA 1991-2020 Climate Normals
0 Start Indoors
0 Plant Outside
118 Harvest
Frost risk: Cleared

Frost season has cleared in Zone 4A. The last spring frost typically passed by May 14, and the very latest 10% chance closed by May 28. Tender crops are safe to plant out.

See full Zone 4A frost outlook →

Start Indoors in September

Nothing to start seeds indoors in September for Zone 4A.
Next window: November — 1 variety, including Garlic.

Plant Outside in September

Nothing to plant or sow outside in September for Zone 4A.
Next window: November — 1 variety, including Garlic.

Harvest in September

Plant Type Planted / Sown Harvest Window
Atlantic Giant Pumpkin squash May 21 Sep 18
Big Max Pumpkin squash May 21 Sep 13 – Sep 18
Birds Eye Hot Peppers pepper May 28 Sep 5 – Sep 15
Bloody Butcher Corn vegetable May 28 Sep 5 – Sep 15
Butternut Squash squash May 28 Sep 5 – Sep 25
Cinderella Pumpkin squash May 21 Sep 8
Evergreen Bunching Onions root vegetable May 14 Sep 11
Grano Red Onions root vegetable May 14 Sep 11
Grano White Onions root vegetable May 14 Sep 11
Green Hubbard Winter Squash squash May 21 Sep 8
Indian Spring Mix Hollyhock Flowers flower May 14 Sep 11 – Sep 20 (before frost)
Luffa gourds vegetable May 28 Sep 5 – Sep 25
Pacific Giant Pumpkin squash May 21 Sep 13 – Sep 23
Rainbow Corn vegetable May 21 Sep 3 – Sep 13
Red Burgundy Onions root vegetable May 14 Sep 1 – Sep 11
Southport Red Globe Onions root vegetable May 14 Sep 11
Southport White Globe Onions root vegetable May 14 Sep 11
Spanish Sweet White Onions root vegetable May 14 Sep 1 – Sep 11
Summer Carnival Mix Hollyhock Flowers flower May 14 Sep 11 – Sep 20 (before frost)
All Season Cabbage (fall planting) brassica Jul 1 Sep 19
All Year Round (fall planting) lettuce Jul 1 Sep 12
All Year Round Cauliflower (fall planting) brassica Jul 1 Sep 4
Amarillo Yellow Carrots (fall planting) root vegetable Jul 1 Sep 14
Angelica (fall planting) herb Jul 1 Sep 29
Autumn King Carrots (fall planting) root vegetable Jul 1 Sep 19
Baby Blue Eyes Flowers (fall planting) flower Jul 1 Sep 29
Bachelor's button edible flowers (fall planting) flower Jul 1 Sep 19
Barletta, Pearly White Onions (fall planting) root vegetable Jul 1 Sep 19
Bouquet Dill (fall planting) herb Jul 1 Sep 4
Broad Windsor Fava Bean (fall planting) legume Jul 1 Sep 24
Broccolini (fall planting) brassica Jul 1 Sep 9
Brunswick Cabbage (fall planting) brassica Jul 1 Sep 29
Butterhead Lettuce (fall planting) lettuce Jul 1 Sep 4
Calabrese Broccoli (fall planting) brassica Jul 1 Sep 4
California Bluebell (fall planting) flower Jul 1 Sep 4
Cascadia Sugar Snap Pea (fall planting) legume Jul 1 Sep 6
Chantenay Carrots (fall planting) root vegetable Jul 1 Sep 9
Charleston Wakefield Cabbage (fall planting) brassica Jul 1 Sep 14
Chinese Forget-Me-Not Flowers (fall planting) flower Jul 1 Sep 24
Chioggia Beet (fall planting) root vegetable Jul 1 Sep 4
Copenhagen Cabbage (fall planting) brassica Jul 1 Sep 4
Cosmic Purple Carrot (fall planting) root vegetable Jul 1 Sep 14
Crimson Clover (fall planting) cover crop Jul 1 Sep 29
Crisphead (fall planting) lettuce Jul 1 Sep 14
Curly Kale (fall planting) lettuce Jul 1 Sep 4
Curly Parsley (fall planting) herb Jul 1 Sep 19
Danvers Carrot (fall planting) root vegetable Jul 1 Sep 19
Dark Green Italian Giant Parsley (fall planting) herb Jul 1 Sep 14
Dark Green Romaine (fall planting) lettuce Jul 1 Sep 9
Di Cicco Broccoli (fall planting) brassica Jul 1 Sep 4
Early Jersey Wakefield Cabbage (fall planting) brassica Jul 1 Sep 14
Early Purple Broccoli (fall planting) brassica Jul 1 Sep 4
Endive / Escarole (fall planting) lettuce Jul 1 Sep 4
Evergreen Parsley (fall planting) herb Jul 1 Sep 24
Flat-Leaf Parsley (fall planting) herb Jul 1 Sep 29
Full Heart Batavian (fall planting) lettuce Jul 1 Sep 29
Georgia Southern Collard Greens (fall planting) lettuce Jul 1 Sep 19
German Chamomile (fall planting) herb Jul 1 Sep 4
Globe Gilia Flowers (fall planting) flower Jul 1 Sep 19
Glory of Enkhuizen Cabbage (fall planting) brassica Jul 1 Sep 29
Golden Acre Cabbage (fall planting) brassica Jul 1 Sep 4
Golden Beet (fall planting) root vegetable Jul 1 Sep 4
Green Arrow Pea (fall planting) legume Jul 1 Sep 9
Hairy vetch cover crop stands (fall planting) cover crop Jul 1 Sep 29
Harris Model Parsnips (fall planting) root vegetable Jul 1 Sep 29
Heritage Rainbow Blend Carrots (fall planting) root vegetable Jul 1 Sep 14
Iceberg (fall planting) lettuce Jul 1 Sep 14
Igloo Cauliflower (fall planting) brassica Jul 1 Sep 9
Kuroda Carrots (fall planting) root vegetable Jul 1 Sep 9
Lacinato Kale (fall planting) lettuce Jul 1 Sep 4
Lacy Phacelia Flowers (fall planting) flower Jul 1 Sep 14
Little Marvel Pea (fall planting) legume Jul 1 Sep 2
Love-in-a-Mist Flowers (fall planting) flower Jul 1 Sep 24
Lunar White Carrots (fall planting) root vegetable Jul 1 Sep 19
Mammoth Dill (fall planting) herb Jul 1 Sep 4
Mammoth Melting Sugar Snow Pea (fall planting) legume Jul 1 Sep 13
Medium Red Clover Cover Crop (fall planting) cover crop Jul 1 Sep 14
Michihili Cabbage (fall planting) brassica Jul 1 Sep 9
Morris Heading (fall planting) lettuce Jul 1 Sep 19
Mâche (Corn Salad) (fall planting) lettuce Jul 1 Sep 23
Nantes Carrot (fall planting) root vegetable Jul 5 Sep 18
Napa Cabbage (fall planting) brassica Jul 1 Sep 29
Nodding Catchfly Flowers (fall planting) flower Jul 1 Sep 29
Nutri-Red Carrots (fall planting) root vegetable Jul 1 Sep 14
Oregon Giant Snow Pea (fall planting) legume Jul 1 Sep 13
Oregon Sugar Pod Snow Pea (fall planting) legume Jul 1 Sep 7
Orion Florence Fennel (fall planting) vegetable Jul 1 Sep 29
Progress No. 9 Shelling Pea (fall planting) legume Jul 1 Sep 1
Purple Carrots (fall planting) root vegetable Jul 1 Sep 14
Purple Haze Carrots (fall planting) root vegetable Jul 1 Sep 12
Radicchio (fall planting) lettuce Jul 1 Sep 24
Rapeseed Cover Crop (fall planting) cover crop Jul 1 Sep 9
Rapini Broccoli Raab (fall planting) brassica Jul 1 Sep 4
Red Acre Cabbage (fall planting) brassica Jul 1 Sep 19
Red Romaine (fall planting) lettuce Jul 1 Sep 9
Romaine Lettuce (fall planting) lettuce Jul 1 Sep 14
Scarlet Flax Flowers (fall planting) flower Jul 1 Sep 9
Shelling Pea (fall planting) legume Jul 1 Sep 9
Snow Pea (fall planting) legume Jul 1 Sep 9
Snow White Carrots (fall planting) root vegetable Jul 1 Sep 14
Snowball Self-Blanche Cauliflower (fall planting) brassica Jul 1 Sep 4
Solar Yellow Carrots (fall planting) root vegetable Jul 1 Sep 14
St. Valery Carrots (fall planting) root vegetable Jul 1 Sep 9
Sugar Snap Pea (fall planting) legume Jul 19 Sep 27
Sweet Marjoram (fall planting) herb Jul 1 Sep 29
Tendersweet Carrots (fall planting) root vegetable Jul 1 Sep 9
Tom Thumb (fall planting) lettuce Jul 1 Sep 9
Tuscany Black (fall planting) lettuce Jul 1 Sep 14
Vates Collard (fall planting) lettuce Jul 1 Sep 14
Vienna Purple Kohlrabi (fall planting) brassica Jul 1 Sep 4
Vienna White Kohlrabi (fall planting) brassica Jul 1 Sep 4
Viola and pansy edible flowers (fall planting) flower Jul 1 Sep 9
Violetta Purple Cauliflower (fall planting) brassica Jul 1 Sep 4
Waltham 29 Broccoli (fall planting) brassica Jul 1 Sep 29
Wando Pea (fall planting) legume Jul 1 Sep 7
Watermelon Radishes (fall planting) root vegetable Jul 1 Sep 4
White Lisbon Bunching Onions (fall planting) root vegetable Jul 1 Sep 4
Yellow Sweet Blossom Clover Cover Crop (fall planting) cover crop Jul 1 Sep 29

Key Tasks for September in Zone 4A

  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 4A planting calendar
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