11 Hardy Vegetables to Sow Indoors in January

It may seem like the middle of the winter, but many slow-growing crops benefit from a headstart indoors to prepare for spring. Join former organic farmer and garden expert Logan Hailey to explore 11 hardy vegetables to sow indoors this month.

Close-up of a freshly picked bunch of radishes with bright pink, rounded roots held by a gardener above a raised bed, a great option fot sowing hardy vegetables.

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Starting seeds indoors has a range of benefits, including bigger transplants, quicker yields, and higher germination rates. But knowing exactly when to sow certain crops can be tricky. It may seem odd to sow vegetables indoors in the middle of winter, but many slow-season, hardy crops benefit from the head start.

Even in far northwestern Montana, seeds were growing in the greenhouse as soon as January. No matter your zone, there are veggies to plant now! Let’s dig into the 11 best hardy vegetables to sow indoors this month.

Mache

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Big Seeded Mache (Corn Salad) Seeds

Kale

Red Russian Kale Seeds

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Red Russian Kale Seeds

Onion

Walla Walla Bulb Onion Seeds

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Walla Walla Bulb Onion Seeds

What Vegetables Can I Sow Indoors in January?

A gardener using a wooden toothpick sowing a tiny seed into a starting tray filled with moist soil.
Prep long-season plants indoors for a strong spring start.

Even with snow on the ground and frosts on the horizon, cozy indoor seed starting setups allow you to jumpstart your spring garden without worrying about harsh weather. Cell trays, heated germination mats, and a south-facing windowsill or grow lights are all you need.

Prioritize cold-hardy vegetables that can handle light frosts, as well as long-season crops with 80-100+ days to maturity. If your last spring frost is late this year, you may need to pot up the seedlings into larger containers to prevent rootbinding or stunting. 

January Crops to Start Indoors in Zone 8 and Colder

Cabbage seedlings in a starting tray feature thin, pale green stems and rounded, slightly crinkled leaves with delicate veining.
Time your planting so seedlings are the right size when it’s time to transplant outdoors.

It may seem like winter is still in full swing, but these crops can benefit from a head start indoors in cold climates. If you have cold frames or a greenhouse, it is particularly advantageous to start now so you have seedlings to put in the ground in a couple of months. However, if you live in more frigid climates, avoid starting seeds too soon, or they may outgrow their containers before it is warm enough to transplant them into beds.

Sow these long-season and cold-hardy vegetables indoors now:

  • Celery
  • Leeks
  • Onions
  • Broccoli
  • Cabbage
  • Cauliflower
  • Mache
  • Spinach
  • Kale
  • Lettuce
  • Claytonia
  • Arugula
  • Cilantro

January Crops to Start Indoors in Zone 9 and Warmer

A gardener's hand in a white glove holds a young tomato seedling in a black pot, showcasing slender green stems and vibrant, serrated leaves, with a blurred background of numerous potted seedlings.
Start your spring crops now for strong plants later.

For zone 9, the estimated last frost date is close on the horizon, while zones 10-12 can plant warm-season crops almost any time of year. This means that it is prime time to start your favorite spring and summer vegetables indoors to ensure they have robust root balls to plant out in a few weeks.

Sow these cool-weather and long-season crops now:

  • Kale
  • Leeks
  • Onions
  • Parsley
  • Peas
  • Radishes
  • Broccoli
  • Cabbage
  • Cauliflower
  • Turnips
  • Asian greens
  • Beets
  • Collard greens
  • Endive
  • Spinach
  • Tomatoes
  • Peppers

11 Hardy Vegetables to Sow Indoors in January

Even with spring far on the horizon, these cold-hardy crops germinate readily indoors so you can transplant out into the garden as soon as the ground is workable. A soil thermometer probe is your best friend for determining the right time to move seedlings outside. Use row cover or cold frames to protect young crops from frigid weather and early-season pests.

Spinach

Tender, dark green, oval leaves with smooth edges grow in a compact rosette on short stems near the soil.
Cold weather makes this crop sweeter.

This notoriously cold-hardy crop can survive extremely cold temperatures when it is overwintered from a fall planting. However, it can still perform very well in late winter if plants get established indoors. The seeds don’t mind germinating in soils as cold as 45°F (7°C) and can tolerate light frosts as young plants. In fact, cold weather makes the leaves sweeter.

Sow spinach under grow lights or in a bright windowsill about 6-8 weeks before your expected last frost, or sooner if you have protected outdoor beds. For warmer zones, maximize your spinach leaf harvests now before higher spring temperatures trigger bolting.

Kale

Tall, sturdy stems support curly textured green leaves with wavy edges growing in loose clusters.
Harvest baby greens in weeks by starting indoors.

It’s no secret that kale is ultra cold-hardy, but did you know that ‘Red Russian’ can tolerate a whopping -10°F (-23°C)!? Instead of purchasing bland, expensive bunches from the supermarket, sow your own baby kale greens indoors and harvest in as little as a few weeks. You can also start seeds in cell trays to prepare for transplanting when outdoor soil temperatures reach 50–60°F (10-16°C).

Mache

Low, rosette-shaped clusters of small, spoon-shaped green leaves have a delicate texture.
Enjoy sweet, nutty greens even in freezing temperatures.

This lesser-known crop was one of my all-time favorites to grow as a far northern organic farmer. While most grocery stores and farm shops were lacking fresh greens, mache shined in the winter months.

Also known as corn salad, mache is a yummy frost-hardy green with a sweet, nutty flavor. It got its name because the plants used to grow as winter weeds in European corn fields, where growers would harvest them for extra vitamins while the picking was sparse.

Mache germinates in soils as cold as 40°F (4°C) and prefers to grow in cold weather. Mature plants can handle down to a chilly 5°F (-15°C) and continuously produce new leaves as long as you harvest the outer foliage, keeping the center growing tip in place. 

Leeks

Long, cylindrical white stems transition to flat, blue-green leaves spreading outward like a fan.
Start indoors now for robust crops by summer.

This unique allium-family crop isn’t particularly cold-hardy when it’s young, but it can handle frigid weather once mature. So why start now? Leeks take a notoriously long time to grow. These onion cousins average 80-150 days to maturity, depending on the variety. 

By starting them indoors now, you can ensure that they will be about pencil-thickness to transplant out after your last spring frost. Don’t forget to give your leek seedlings a haircut when they are about 6” tall, as this encourages stronger root development.

Onions

Upright, hollow green leaves grow from a bulb partially exposed above the soil surface.
Early starts give you the best harvest possible.

Onions can be directly sown as soon as 4 to 6 weeks before your last frost date, but most varieties benefit from germinating in open flats 10 to 12 weeks before the last frost. These hardy vegetables take 100-150 days to mature, so it’s important to give them enough time to grow in regions with short seasons. 

Zones 5 and colder should grow long-day or day-neutral varieties like ‘Cabernet’ or ‘Yellow Sweet Spanish Utah Bulb Onion.’ In warmer zones, be sure to select short-day varieties like ‘Walla Walla’ or ‘Texas Early Grano.’  

Arugula

Thin stems bear deeply lobed, peppery green leaves forming loose clusters near the ground.
Enjoy fresh greens all season long with an indoor start.

Also known as rocket, arugula has a peppery spice in hot weather, but remains mild and sweet in cold temperatures. The delicious green thrives with an indoor start as baby greens or transplants. The seeds don’t mind germinating in soils as cold as 40°F (4°C), and young plants handle frost well under the protection of a row cover.

Radish

Oblong red roots sprout bushy green leaves on slender stems.
Grow easygoing crops indoors for a speedy spring treat.

These beginner-friendly vegetables are easygoing and quick to mature. They are the perfect crop for late winter and early spring, and contrary to popular belief, you can grow them indoors. Radishes don’t have to be directly sown, as they can grow to a perfect 2-3” diameter in a pot or container. 

However, they can still be transplanted as well, as long as you protect the taproots from damage. Soil blocks a great hack for transplanting root crops and defying the rule that “root crops can’t be transplanted.”

Turnip

A gardener holds a freshly harvested bundle of smooth, round white roots with purple tops and tall, lobed green leaves sprouting from upright stems.
Harvest crisp, sweet roots by late spring.

Cold-hardy turnips offer tasty, crisp roots beneath their spicy, mustard-like greens. The seeds germinate in soils as cold as 50°F (10°C) and mature in just 30-40 days. ‘White Lady’ turnip is the trendiest variety amongst chefs and culinary enthusiasts because it has a delicate, sweet taste and nice apple-like crunch when eaten fresh. 

Sow the seeds in soil blocks or cell trays in bundles of three or four seeds per cell. Transplant into the garden once the soil is workable and harvest the bright white globe roots when they are about 3” in diameter.

Beets

Round, slightly flattened purple-red root grows with reddish stems and large, heart-shaped green leaves.
Transplant with care for delicious, colorful roots in weeks.

Cold temperatures trigger these chard relatives to develop extra brightly colored roots with more concentrated sugars. Beets are resilient and hardy, making them the perfect seeds to sow in January. Again, you can ignore the “don’t transplant roots rule” because beets transplant remarkably well, especially when sown in clumps of three to four seeds per cell. 

Plant about 4 weeks before your average last frost date or several weeks sooner if you have a protected outdoor growing space. Carefully remove root balls from containers and place them in the ground gently to avoid crushing the taproots.

Broccoli

Thick, sturdy stems support dense clusters of small green buds surrounded by large, lobed green leaves.
In cold climates, avoid rootbinding by waiting for warmer spring weather.

This cold-weather brassica thrives as a fall or spring crop. For spring plantings, it helps to get started inside in late winter. About six weeks before your expected last spring frost, sow one seed per cell in 4-pack or 6-pack trays filled with a well-draining mix. 

To avoid rootbinding and overgrown seedlings, gardeners in zones 6 and cooler should wait another month or so to start this brassica and related crops like cauliflower and cabbage.

Fava Beans

Tall, upright stems bear oval, waxy green leaves and pods filled with plump green beans.
Start beans indoors early for an early spring bounty.

Unlike their warm-weather bean relatives, favas are remarkably hardy vegetables that are perfect for sowing in late winter to prepare for spring. Some growers prefer to direct sow fava beans, but I’ve found great success starting them even earlier indoors.

While direct sowing is better for cover crop favas, if you want to grow these beans for their tasty edible pods, start them in small cell trays up to 12 weeks before your expected last frost. Transplant outdoors as soon as the soil is workable. The seeds can germinate in soils as cold as 35°F (2°C), making them ideal for outdoor winter sowing as well. 

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