Harvesting Nasturtium Seeds: Drying and Storing for Next Year’s Blooms

Harvesting nasturtium seeds is your ticket to next year’s vibrant blooms without spending a dime. 🌿 I’ve saved seeds from my garden for years, and the trick lies in timing—wait until the pods turn from green to papery brown before collecting.

If you pick too early, the seeds won’t germinate; too late, and they’ll scatter everywhere.

You’ll need just a few simple tools: sharp scissors or pruners, a paper bag for drying, and a cool, dry spot to store them. Nasturtium seeds are tough little survivors, but they need patience—let the pods dry on the plant for a full week before harvesting.

This ensures they’re fully mature and ready for storage.

The payoff is worth the wait: fresh seeds mean healthier plants and stronger blooms the following season. You’ll also have extra to share with friends or swap at garden clubs. Just avoid damp storage—moisture ruins seeds faster than any pest could.

This method works for all nasturtium varieties, from classic reds to golden ‘Empress of India.’ Once you master it, you’ll never buy seeds again—and your garden will thank you with bold, cheerful flowers year after year.

What you need

Step-by-Step instructions for harvesting nasturtium seeds

Here's how I save seeds from my nasturtiums each year—simple, reliable, and ready for next season.

Wait until the seed pods turn from green to a papery brown color—this means they're fully mature and ready for harvest. I pick pods when they're dry but still firmly attached to the vine. Gently twist or snip them off with clean scissors, leaving some pods on the plant for pollinators.

Choose pods from the healthiest, most vigorous plants in your garden. Avoid pods that look shriveled or have signs of disease, like black spots or mold. You'll know you've picked at the right time when the pod splits open easily with a slight tug.

Spread the harvested pods on a clean, dry surface in a well-ventilated area. I use a mesh screen or an old window screen to allow air to circulate freely. Keep them out of direct sunlight—too much heat speeds up drying and can damage the seeds inside.

Let the pods dry for 7-10 days until they feel crisp and hollow when tapped. If you're in a humid climate, this process might take longer. Check daily to avoid over-drying. Once fully dry, the pods will split open on their own, releasing the seeds inside.

Once the pods have split open, carefully remove the seeds and place them in a bowl. I use a small brush or my fingers to separate the seeds from any remaining pod debris. Nasturtium seeds are small and flat, with a distinctive orange or brown color.

To clean them, spread the seeds on a clean paper towel and gently shake off any remaining chaff or dust. Avoid washing them—they're sensitive to moisture and can spoil quickly. You'll end up with about 4-5 teaspoons of seeds per plant, depending on the variety.

Transfer the cleaned seeds into a small, airtight container like a glass jar or envelope. Label it with the variety name and the harvest date. I like to add a silica gel packet to absorb any excess moisture, which helps keep the seeds viable longer.

Store the container in a cool, dark place, like a pantry or fridge. Nasturtium seeds stay viable for 3-5 years when stored properly. Check them occasionally to ensure no moisture has seeped in, which can cause mold or spoilage.

Before you plant the saved seeds next year, do a quick viability test. Place a few seeds between damp paper towels in a sealed plastic bag. Keep them in a warm spot for 3-5 days. If the seeds sprout, they're ready to plant. If not, they may need to be replaced.

This simple test saves you from wasting time planting seeds that won't grow. Once you confirm viability, you're ready to start your nasturtiums again—just like fresh from the garden!

Tips & tricks for perfectly harvested nasturtium seeds

A few simple tricks will help you maximize your seed yield and ensure they stay viable for years to come.

Selection Tip: In Step 1, when choosing seed pods, focus on those that are slightly larger and more plump—they'll contain the most seeds. I've found that pods from the first flush of flowers often produce the most vigorous seeds for next year's plants. Avoid pods that have already split open naturally, as those seeds may have already dispersed or been eaten by birds.

Drying Strategy: For Step 2, if you're in a particularly humid climate, consider placing a small fan nearby to gently circulate air around the pods. This can cut your drying time from the full 7-10 days to about 5-7 days. Just be careful not to create a draft that could blow the pods around—you want that gentle airflow, not strong winds.

Cleaning Technique: When cleaning seeds in Step 3, I've found that using a fine-mesh strainer instead of a paper towel works wonders for removing chaff. Simply place the seeds in the strainer and gently tap it over a bowl. The seeds will fall through while the lighter debris stays behind. This method is especially helpful if you're dealing with a large harvest.

Storage Wisdom: In Step 4, don't overlook the importance of that silica gel packet. It's not just about moisture—it also helps prevent condensation from forming inside your container during temperature fluctuations. I like to place the packet inside a small breathable bag before adding it to the seed container, which keeps it from directly touching the seeds.

Frequently asked questions

When is the best time to harvest nasturtium seeds?

Harvest seeds when the seed pods turn papery brown and start splitting open—usually 6–8 weeks after flowering. If you wait too long, seeds may scatter or sprout inside the pod. For a head start, pick pods just before they crack open for extra drying time.

How long does it take to dry nasturtium seeds?

Drying takes 1–2 weeks in a cool, dry spot (like a paper bag with airflow). Speed it up by placing pods in a single layer on a mesh screen or brown paper bag. Avoid heat sources—moisture is the enemy! Test readiness by gently crushing a pod; seeds should rattle freely.

Can I save seeds from store-bought nasturtiums?

Probably not! Store-bought flowers are often hybrids or treated to prevent seed production. For reliable seeds, grow open-pollinated varieties (like ‘Alaska’ or ‘Jewel Mix’) from a trusted seed supplier. If you’re unsure, test a few seeds—germination rates will tell you all.