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How to Harvest Nasturtium Seeds

Collecting nasturtium seeds is the easiest seed saving that I have done! These easy to grow plants are great to have in your garden. Once you learn how to harvest nasturtium seeds at the end of the growing season, you will be able to grow these edible flowers every year without needing to pay for seed packets again.

What Do Nasturtium Seeds Look Like?

Nasturtium seeds look like shriveled, dried brown peas. They are about the size and shape of a pea. Dried seeds will be tan, but freshly fallen seeds will be green.

Dried nasturtium seeds are tan, hard and shriveled. They resemble tiny brains.

These seeds actually look like little brains! That’s what makes them easy to spot in the garden soil once they have fallen! They also resemble chickpeas, too.

Nasturtium seeds on the vine are green and plump.

Harvesting Nasturtium Seeds

At the end of the plant’s growing season, around late summer or fall, nasturtium seeds are ready to be harvested to keep for the next year’s garden.

Harvesting the flower seeds could not be any easier. In fact, this is a great activity for kids to do! It is similar to an Easter egg hunt, peeking under plants and digging in the dirt to find hidden treasures!

Some nasturtium seeds will be found already dried on the ground. These seeds probably fell off earlier in the season and have had time to dry out. All you need to do is pick the seeds up from the ground to collect them.

The seeds are most often found underneath the plant. They often are found in clumps of three, but not always. The clumps won’t be attached together, but probably laying next to each other on the ground.

Nasturtium seeds are often found in clumps of three. However, clumps of two or four are common on the plant, as well.

You may find a single nasturtium seed on the ground, perhaps because a bird or animal has eaten or moved the others. More common, though, is to find clumps of seeds, either two, three or four seeds together.

If you only find one seed underneath the nasturtium plant, take a moment to make sure there were not any more.

Nasturtium seeds can also be found on the plant’s vine, too. These green-colored seeds are usually found in clumps of three while on the plant stems.

Only pick seeds off of the nasturtium plant if they come off very easily. For instance, I was able to gently touch the seed clusters on some stems and the seeds easily popped off the vine. I did not pull or tug on the seeds. Just a gentle touch released them from the plant, signaling that they were ready to harvest.

A collection of harvested nasturtium seeds from my garden. Some were brown and dried, while others were plump and green.

However, if you gently tug or pull on the seeds and they will not release from the plant, then they are not ready to harvest. These are immature seeds and will likely not germinate next year. Leave them on the stems until they mature and are ready to harvest.

Important Note: Harvest nasturtium seeds before rain if possible. I was unable to save many seeds because they were in damp soil underneath the plant and had begun to rot.

Harvesting nasturtium seeds is ideally done before a frost or freeze. However, my nasturtium plants survived four nights of freezing temperatures in zone 7 and my plants continued to grow, flower and produce seeds after the frosts.

Seed saving is ideally suited for organic, heirloom or open-pollinated plants. I purchased my original seed packet of nasturtiums from Botanical Interests, which sells heirloom varieties of nasturtiums.

Related Posts – You might also like these easy gardening crafts:

How to Dry Nasturtium Seeds

The brown seeds that you pick off of the ground are dried already. Lay them on a paper towel for a few days to make sure any outer moisture has evaporated.

Green seeds that are collected off of the ground or plant need time to dry out, harden and become a tan color. Lay these seeds on a paper towel, paper plate, brown paper, cardboard or a mesh drying rack and give them time to dry. This can take weeks, so be patient. They must be completely dried out in order to germinate next year.

Nasturtium seeds drying on paper towels after harvest.

When drying seeds, air flow is important. You do not want to lay seeds on plastic because air cannot easily circulate around the seed, as it can with porous paper products.

How to Store Nasturtium Seeds

Once the seeds are dry, shriveled and brown, you can store them for next year’s garden. Store seeds in a paper bag or a glass jar without a sealed lid.

You do not want to store seeds in a glass jar or plastic jar that is sealed with a lid. There is not adequate air flow in the container for the seeds, and moisture may be trapped inside the jar, which could then make the seeds mold or germinate too early.

Put the container of seeds in a cool, dry place. Be sure to label the container with the flower name, and variety if necessary. Add any gardening tips that you learned from this year’s harvest to the label so that you will remember for next year’s garden.

Be sure to see my Youtube video harvesting nasturtium seeds so you can see how easy it is:

If you enjoyed this easy tutorial of how to save nasturtium seeds, you will also like the easy method to harvest cosmos seeds, too.