How To Grow Cabbage And Broccoli From Seed

A couple of days ago I started my cabbage and broccoli seeds. I know it seems early, but last year I started my seeds indoors on the 22nd of January, and it actually worked out well.

They did fantastically… until I fried them by leaving them under a row cover in the heat of the day. Oops. This year, I vow to do better.

Cabbage is a cool weather crop. Seedlings actually need to be planted in your garden about 4 weeks before your last frost date in Spring, and 4-6 weeks before your first Fall frost. (Don’t worry, the frost won’t kill these plants.)

When growing plants from seed, you need to get them started 4-6 weeks before planting time, so they’ll have time to grow their true leaves and will be strong enough to transplant.

Before you ask, yes, cabbage can be direct sowed, meaning you can put the seeds straight into the ground instead of starting them indoors and then transplanting them.

Direct sowing is definitely lower maintenance. But I’m impatient. And I like to see immediate results when I put something into my garden beds. So I start them early.

At least it’s comforting to know that if my seedlings don’t do well I can always direct sow at a later date and still have time for a harvest before the summer heat causes my plants to bolt. (Bolting is when they go to seed and get bitter.)

Starting cabbage from seed is super easy. Here’s how I do it…

First, get your hands on some containers to start seeds in. I’ve used yogurt cups with great success. I happened to have these trays this time around, so that’s what I’m working with:

Fill your containers with seed starting mix. Make sure it specifically says Seed Starting and not just Potting Mix. Plain ol’ potting mix doesn’t have the nutrients seedlings need to thrive. Ask me how I learned that one.

Once your containers are filled, soak them thoroughly. If you are on city water, you may need to use filtered water for your plants. There are very harsh chemicals in treated city water which will hinder the growth of your seedlings.

Select the seeds you’d like to plant. I’m going with Mammoth Red Rock Cabbage, and Henderson’s Charleston Wakefield Cabbage. Look into which varieties grow best in your area. I chose heirloom varieties so that I can save the seeds from the plants I grow for next year’s crop.

(This will be my first time growing purple cabbage.)

Plant the seeds about 1/4″ deep in your seed starting mix. I like to poke a little hole in the dirt, drop the seed in, then cover it back over. I recommend planting two seeds per container, just in case one of the seeds doesn’t germinate.

Some people do three at a time, but I’ve found that to be quite wasteful- you can only allow one plant per tray cell to grow, and if all three seedlings emerge, two would be wasted.

The soil must stay moist while the seeds germinate. I like to bottom water mine, so as not to disrupt the seeds by watering from above.

Here you can see that I’ve got my seeds sitting in my kids’ play table with a couple inches of water in the bottom:

I’ve seen people spray their trays with a spray bottle, which also works well. I tend to be forgetful, and would probably let my seeds dry out if I didn’t bottom water.

Don’t forget to label your trays. Broccoli seedlings and cabbage seedlings look identical when they come up, making it easy to confuse which is which.

Also make a note of when you started your seeds so you can write in your garden journal how long it took your seeds to germinate. Keep track of how many weeks old they are to best judge transplanting time.

As a side note, I had my seed tray just like this in my greenhouse when it got super cold one night and the water in the table actually froze into a giant block of ice.

After it thawed out, I brought my seed trays indoors so they wouldn’t freeze again. So far, they’re taking longer than usual to germinate. I’m sure the freeze set them back.

I usually cover my filled trays with loose plastic bags, to create a mini greenhouse effect, and set them on top of the fridge to germinate in a warm place. I was hoping the greenhouse would stay warm enough, but no such luck for right now anyways.

Do you know a special trick for growing cabbage from seed? Any questions I can help answer for you?

Kendra Lynne

A city girl learning to homestead on an acre of land in the country. Wife and homeschooling mother of four. Enjoying life, and everything that has to do with self sufficient living.