Seed Saving: How to Save Kale Seeds

Let’s talk about how to save kale seeds. It’s always exciting to know that there is always MORE I can learn about for gardening. This year, I’m learning about how to save seeds.

Previously, I’ve always gotten all the seeds I need from True Leaf Market. This year I’m trying to save as many seeds as I can on my own and then supplement and try new seeds from True Leaf.

One of the worst parts of the return of summer heat is when your beloved plants start showing signs of heat stress, like beginning to bolt. Once a plant starts to bolt, the leaves and/or fruit gets tougher and less tasty. 

In the past, I would silently mourn the changing of seasons and pull up my bolting plants to make-way for heat-loving plants. Don’t worry, there was no waste: I either fed them to my rabbits or chopped them up into my compost pile.

However, I’ve been wanting to learn about seed saving for YEARS now, and, after seeing some of my carrots, kale, and mustard greens go to seed at the same time, I figured this year was the perfect time to start learning how to save seeds. 

I mean, if I can save money on future seed purchases, maybe I can put that saved money toward expanding my garden again. Sounds good, right, hubby? 🙂

By the way, if you struggle with garden burnout in the summer, read my post about Finding Joy in the Garden in Summer.

How to Save Kale Seeds

1. What You Need To Know Before Saving Kale Seeds

Before we talk more about how to save kale seeds, there is a few details about saving seeds and also about kale that we should talk about. Honestly, seed saving has always overwhelmed me because it can get a bit….”science-focused” and science isn’t really that interesting to me (Note: I assume that my husband’s science-loving relatives just sighed sadly).

So I’m going to make this seed saving stuff as easy-to-understand as possible. If you want to delve into the complexities of seed saving, I suggest reading one (or both) of these books:

• Seed to Seed: Seed Saving and Growing Techniques for Vegetable Gardeners by Suzanne Ashworth
• The Complete Guide to Saving Seeds: 322 Vegetables, Herbs, Fruits, Flowers, Trees & Shrubs by Robert E. Gough & Cheryl Moore-Gough

So, back to some uber-simple seed saving tips:

1) Start with Kale plants that are either listed as “open-pollinated” or “heirloom”.

You want to avoid hybrid plant varieties. By the way, just because a plant is organic does not mean that can’t also be a hybrid. 

Okay, you might be thinking “But Cris, I threw my kale seed packet away a LOOONG time ago. How do I know if it was a hybrid or not?”

If you order your seeds online, you should be able to find your receipt order again (even if you have to email the company). These are my favorite seed companies by the way.

Otherwise, you can try looking up the variety you are growing online via beloved google, and see if it is a hybrid or not.

If you’re not sure if it is or is not a hybrid, why not try saving the kale seeds anyway? A hybrid’s seeds don’t usually work, so worst case scenario, your experiment fails and you learn a valuable lesson about labeling everything (coming from the gal who is still learning that lesson on a daily basis).

Best case scenario: you “discover” a delicious new variety. Or something. Ugh, it gets too science-based at this point. Sorry guys.

2) Avoid Cross Pollination Issues by Isolating Your Kale Plant from Other Kale Varieties.

If you are growing more than one variety of heirloom/open-pollination kale plant, then you need to make sure that your two kale crops are planted away from each other (not in the same garden row/bed).

If you have two heirloom varietiess next to each other, no worries, all is not lost, you are just going to create a mixed/hybrid variety from the seeds.

However, if you are looking to do this kale seed saving thing longterm, you will need to plant your (future) heirloom varieties away from each other in your next gardening season. In the meantime, you can experiement with the mixing of your kale varieties. 

2. Caring for and Observing Your Kale Plant

Kale is a biennial plant, which means that if you want to save seeds from your kale plant, you will keep your kale plants in the garden over the winter and harvest the seeds from your kale plants the following summer. 

I planted my kale last spring, harvested leaves throughout the summer and fall, ignored the plant during the winter, and this spring, it flowered. That’s when it’s getting ready to give me my future seeds.

Once your kale plants flower, you won’t find the leaves very tasty anymore. It is now putting energy into the flowers, and, by the way, don’t harvest or cut off the flowers, because those flowers eventually turn into seed pods.

Many beneficial insects like the yellow flowers of kale. I found the first bees and butterflies of the season all over kale flowers, probably because other flowers weren’t available to them yet. So make sure you enjoy the flower stage! Sit by your kale plants and admire the beauty.

You might need to stake the flower stalks. The flower stalk can get very tall and fall over, and if they get damaged and snap off at this stage, you won’t get any kale seeds.

3. When to Harvest the Kale Seed Pods

After the flower stage, the plant will develop long, skinny green pods on the plant.

You only need one or two kale plants per variety for seed saving. Each plant produces LOTS of seeds!

Leave the green pods on the plant, but keep an eye on them. You cut the branches with seed pods off when the seed pods turn brown and they are dry. Use your gardening intuition about the perfect time to harvest the seed pods.

In the photo below, you will see that only half of my pods turned brown. I harvested them slightly early because some of the brown pods were splitting open and I was losing my seeds and also because a week of rain was about to start, and you need to harvest the seed pods when they are dry or you risk moldy seeds.

Unless you want the kale to self-seed where it is in your garden, you need to watch carefully for brown seed pods splitting open. 

4. How to Dry Your Kale Seed Pods

Once your kale seed pods are ready to be harvested, here’s what you do:

1. Cut the stalks at the bottom of the plant. Wait at least 2 days after it rains to harvest your seed pods or you risk mold.
2. Gently place the kale stalks in a brown paper bag. Do this carefully or you risk splitting open seed pods and having kale seeds spill all over your kitchen counter. Ask me how I know that. 😉
3. Label your brown paper bag. If you’re seed saving with different plants or even different varieties of kale plants, you need to LABEL them, or you might forget which bag is holding which seeds.
4. Hang the brown bag somewhere out of the way, perferably in a dark, room temperature place.

5. How to Winnow Your Kale Seeds

After a few weeks, check to see if your pods are completely dry in the brown bag. Once they are all ready, it’s winnowing time!

There are a few ways to winnow your kale seeds:

• Make sure your brown bag is closed and shake the bag to get the seeds out of the pods.
• Place the seed pods on a screen, sheet, colander, or cheesecloth, and shake it (over a container) so that the seeds fall out and the seed pods are left behind.
• Sit down on a porch with a tall glass of lemonade, and hey, maybe get your loved one to play guitar, while you pluck the seeds out of the seed pods by hand. (This is what I like to do. I’m all about slowing down these days instead of rushing about!).

6. How to Store Your Kale Seeds

Now that you learned how to save kale seeds, make sure you put them in a closable bag or sealed envelope and LABEL IT!!!!!

I always store my seeds in the back of my refrigerator. Cold, dark storage places can keep your seeds viable for many years. Here’s how you can check the viability of old seeds.

Worst case, when I check the viability of my saved seeds next year I know that I can always just order extra seeds from True Leaf Market when needed. Shipping has always been very quick so even if my saved seeds aren’t perfect my gardening season won’t be ruined. 

Do you save seeds? Have you saved kale seeds before? Tell me about your seed saving adventures in the comments below!

I hope you learned a lot of great tips about how save kale seeds. I’ll be posting more seed saving posts in the future, but in the meantime, check out my Ultimate Gardening Guide for lots of awesome gardening tips!