10 Vegetable Seeds to Start Indoors in Winter Before It’s Too Late

Most indoor seed starting begins just weeks before last frost in spring. But some plants like the vegetable cultivars listed here are slow-growing and need a much longer jump start. Started indoors in winter and planted out in late spring, they’ll have time to mature before fall.

If you are interested in outdoor sowing, I have two winter sowing methods here.

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Slow-Growing Vegetables to Start Early

Indoor seed starting is a simple way to extend the growing season, allowing us to grow a much wider variety of plants than we could with direct outdoor sowing alone.

Seed packets typically recommend a specific timeline (number of weeks before last frost) for starting seeds indoors to get plants established for transplanting outdoors in spring.

What surprises gardeners is not all cultivars of the same species have the same time requirements.

• For example, the days to maturity for Early Girl tomatoes are just 50 days while Brandywine tomatoes require twice as long—100 days.
• Aspabroc broccolini takes 56 days while Santee broccoli needs up to 115 days.

Those are big differences for the same vegetables!

This is why it’s smart to read your seed packets, flag the slow-growers, and start them much earlier in late winter.

Be sure you have room under your grow lights not only for trays of seedlings but for moving the plants into larger pots (3-6 inches in diameter) as they grow. They take up a lot more space as they grow.

I use this system to sow batches every two weeks from winter onward to make sure everything starts on time.

It’s helpful to know your average last frost date and typical number of frost-free days from spring to fall to get started. I’ve listed a calculator for this and other helpful items in the Resources section.

Slow-Growing Vegetables to Start Extra Early

These examples come from seed catalogs. These are all cultivars that need more time than we expect—especially those that we’d like to reach a good size before harvest time.

As mentioned, my indoor seed sowing plan is organized into two week batches to simplify things.

And always check your seed packets for specific growing instructions.

Broccoli

• Early Broccoli: Early broccolis are faster growing but often do best in cooler weather. If you want to plant them out in spring, you’ll want to sow seeds indoors in winter.
• Santee Broccoli (80-115 days)
• Calabrese Broccoli (60-90 days)
• Purple Sprouting Broccoli (90-100 days)
• Romanesco Broccoli (75-100)

Celeriac

• Giant Prague (110-120 days)
• Brilliant (105-115 days)
• Monarch (110 days)

Celery

• Tall Utah (90-100 days)
• Golden Self-Blanching (90-120 days)
• Tango Hybrid (85-90 days)

Eggplant

• Black Beauty (74 days)

Leeks

• Giant Musselburgh (105 days)
• Otina (120 days)
• Splendid (95-105 days)

Onion

Sweet onions in particular can be slow-growers. It takes a long time to grow those large bulbs.

• Walla Walla (125 days)
• Sweet Spanish (110 days)
• Trident (115 days)

Peppers

• Chili peppers (Capsicum chinense) including Habanero types require 90-120 days to mature after transplanting.
• Anaheim (75-80 days)
• California Wonder (70 days)

Tomatoes

• Mortgage Lifter (85 days)
• Amana Orange (80 days)
• Cherokee Purple (80 days)
• Brandywine (90-100 days)
• Chef’s Choice Orange (75 days)

Resources

~Melissa the Empress of Dirt ♛