When to plant onion

Hardy · tolerates frost

Onionis keyed to your local frost dates. The offsets below hold anywhere — but the calendar dates they land on don’t. Enter your ZIP for dates tuned to your city’s nearest NOAA station.

Onion planting timeline

Start indoors

8–10 wks before

Transplant out

2–4 wks before

Harvest

90–110 days later

-11 wksLAST SPRING FROST+13 wks

Hardy: tolerates frost and can go out a few weeks before the last spring frost.

Shop onion seeds →AFFILIATE

Onion planting FAQ

When should I start onion seeds indoors?

Start onion indoors 8–10 weeks before the last spring frost, so seedlings are ready to plant out once the weather warms.

Can I direct sow onion?

Onion is usually started indoors and transplanted rather than direct sown, for a reliable stand.

How long does onion take to grow?

Onion takes about 90–110 days from transplanting to harvest, depending on the variety and conditions.

Is onion frost-hardy?

Hardy: tolerates frost and can go out a few weeks before the last spring frost.

Planting reminders

Never miss a window in your area

An email when it’s time to start seeds, transplant, and sow — timed to your frost dates. Double opt-in, one-click unsubscribe, no spam.

Other crops

155 more

Acorn Squash Amaranth Anise Apple Apricot Arugula Asparagus Avocado Basil Bay Laurel Beet Bitter Melon Black Currant Blackberry Blueberry Bok Choy Borage Boysenberry Broccoli Brussels Sprouts Bush Bean Butternut Squash Cabbage Cantaloupe Caraway Cardoon Carrot Cassava Catnip Cauliflower Celeriac Celery Chayote Cherry Chervil Chives Cilantro Claytonia (Miner's Lettuce)Collards Coriander (Seed)Corn Salad (Mâche)Cowpea (Southern Pea)Cranberry Cucumber Delicata Squash Dill Edamame Eggplant Elderberry Endive Epazote Escarole Fennel (Bulb)Fenugreek Fig French Tarragon Gai Lan (Chinese Broccoli)Garlic Garlic Chives German Chamomile Globe Artichoke Goji Berry Gooseberry Gourd Grape Ground Cherry Hardy Kiwi Honeyberry (Haskap)Honeydew Melon Horseradish Hot Pepper Hyssop Jerusalem Artichoke (Sunchoke)Kale Kiwi Kohlrabi Lavender Leek Lemon Lemon Balm Lemongrass Lettuce Lima Bean Lime Lovage Luffa Malabar Spinach Marjoram Mint Mizuna Molokhia Mulberry Muskmelon Mustard Greens Napa Cabbage Nectarine New Zealand Spinach Okra Olive Orach Orange Oregano Parsley Parsnip Pawpaw Peach Pear Peas Pepper Persimmon Plum Pole Bean Pomegranate Popcorn Potato Pumpkin Purslane Quince Radicchio Radish Raspberry Red Currant Rhubarb Rosemary Runner Bean Rutabaga Sage Salsify Scallion (Green Onion)Scorzonera Shallot Shiso (Perilla)Shungiku (Edible Chrysanthemum)Sorrel Spaghetti Squash Spinach Stevia Strawberry Summer Savory Summer Squash Sunflower Sweet Corn Sweet Potato Swiss Chard Tatsoi Thyme Tomatillo Tomato Turnip Watercress Watermelon Winter Savory Winter Squash Yardlong Bean Zucchini

Planting windows are offsets from your local 1991–2020 NOAA frost normals. How we compute this.