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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 121 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
121 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: February — 4 varieties, including Green Onion, King Richard Leek, Leek.

Plant Outside in September

Nothing to plant or sow outside in September for Zone 4A.
Next window: October — 11 varieties, including Asian Tempest Garlic, Chengdu Garlic, Chesnok Red Garlic.

Harvest in September

Plant Type Planted / Sown Harvest Window
Atlantic Giant Pumpkin squash May 21 Sep 8
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
Carolina Cross Watermelon melon May 28 Sep 5
Cinderella Pumpkin squash May 21 Sep 13
Goldrush Potato root vegetable May 21 Sep 9 – Sep 18
Grano Red Onions allium May 14 Sep 11
Grano White Onions allium May 14 Sep 11
Green Hubbard Winter Squash squash May 21 Sep 8
Green Striped Cushaw Crookneck Winter Squash squash May 21 Sep 3
Harris Model Parsnips root vegetable May 21 Sep 13 – Sep 18
Indian Spring Mix Hollyhock Flowers flower May 14 Sep 11 – Sep 20 (before frost)
Long Island Cheese Winter Squash squash May 21 Sep 6
Luffa gourds vegetable May 28 Sep 5 – Sep 25
Mammoth Sandwich Island Salsify root vegetable May 21 Sep 18
Pacific Giant Pumpkin squash May 21 Sep 13 – Sep 23
Rainbow Corn vegetable May 21 Sep 3 – Sep 13
Red Burgundy Onions allium May 14 Sep 1 – Sep 11
Southport Red Globe Onions allium May 14 Sep 11
Southport White Globe Onions allium May 14 Sep 11
Spanish Sweet White Onions allium May 14 Sep 1 – Sep 11
Summer Carnival Mix Hollyhock Flowers flower May 14 Sep 11 – Sep 20 (before frost)
Tall Utah 52-70 Celery vegetable May 28 Sep 5 – Sep 20 (before frost)
Waltham Butternut Squash squash May 28 Sep 5 – Sep 25
Adirondack Blue Potato (fall planting) root vegetable Jul 1 Sep 26
All Season Cabbage (fall planting) brassica Jul 1 Sep 19
All Year Round Cauliflower (fall planting) brassica Jul 1 Sep 4
All Year Round Lettuce (fall planting) lettuce Jul 1 Sep 12
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) allium Jul 1 Sep 19
Bouquet Dill (fall planting) herb Jul 1 Sep 4
Broad Windsor Fava Bean (fall planting) legume Jul 1 Sep 19
Broadleaf Full Heart Batavian Endive (fall planting) lettuce Jul 1 Sep 29
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
Chantenay Carrots (fall planting) root vegetable Jul 1 Sep 9
Charleston Wakefield Cabbage (fall planting) brassica Jul 1 Sep 9
Chinese Broccoli (Gai Lan) (fall planting) brassica Jul 1 Sep 9
Chinese Forget-Me-Not Flowers (fall planting) flower Jul 1 Sep 24
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 Lettuce (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 Lettuce (fall planting) lettuce Jul 1 Sep 9
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 Bunching Onions (fall planting) allium Jul 1 Sep 4
Evergreen Parsley (fall planting) herb Jul 1 Sep 24
Flat-Leaf Parsley (fall planting) herb Jul 1 Sep 29
Georgia Southern Collard Greens (fall planting) lettuce Jul 1 Sep 24
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
Heritage Rainbow Blend Carrots (fall planting) root vegetable Jul 1 Sep 14
Iceberg Lettuce (fall planting) lettuce Jul 1 Sep 14
Igloo Cauliflower (fall planting) brassica Jul 1 Sep 9
King Richard Leek (fall planting) allium Jul 1 Sep 14
Kuroda Carrots (fall planting) root vegetable Jul 1 Sep 9
Lacinato Kale (fall planting) lettuce Jul 1 Sep 4
Little Marvel Pea (fall planting) legume Jul 1 Sep 2
Love-in-a-Mist Flowers (fall planting) flower Jul 1 Sep 9
Mammoth Dill (fall planting) herb Jul 1 Sep 4
Mammoth Melting Sugar Snow Pea (fall planting) legume Jul 1 Sep 14
Medium Red Clover Cover Crop (fall planting) cover crop Jul 1 Sep 14
Michihili Cabbage (fall planting) brassica Jul 1 Sep 9
Morris Heading Collard (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 9
Nodding Catchfly Flowers (fall planting) flower Jul 1 Sep 29
Nutri-Red Carrots (fall planting) root vegetable Jul 1 Sep 9
Oregon Sugar Pod Snow Pea (fall planting) legume Jul 1 Sep 7
Orion Florence Fennel (fall planting) vegetable Jul 1 Sep 19
Par-Cel Cutting Celery (fall planting) vegetable Jul 1 Sep 24
Paris Market Carrots (fall planting) root vegetable Jul 1 Sep 4
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
Queen Anne's Lace Flowers (fall planting) flower Jul 1 Sep 14
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 Lettuce (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
Tendersweet Carrots (fall planting) root vegetable Jul 1 Sep 9
Tom Thumb Lettuce (fall planting) lettuce Jul 1 Sep 9
Tuscany Black Kale (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
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
Yellow Sweet Blossom Clover Cover Crop (fall planting) cover crop Jul 1 Sep 29
Yukon Gold Potato (fall planting) root vegetable 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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