How to Harvest and Save Physalis Seeds from Your Own Plants

The easiest way to keep your garden full of ground cherries (Physalis) is to sow them fresh every year. The best part? You can easily save seeds from your own harvest! To make sure those seeds actually sprout next spring, timing is everything.

Harvesting Your Physalis

You can usually start harvesting your Physalis around August. However, if you’re growing certain varieties or if you’ve overwintered your plants, you might see fruit as early as June. If you’re planning on saving seeds, you need to wait until the fruit is fully, 100% ripe. You’ll know they’re ready when they drop off the plant all on their own.

Pro tip: Let the fallen fruit sit out for a few extra days. While they don’t ripen a whole lot more once they’ve dropped, the seeds become much easier to separate from the pulp when the berry is super soft.

Extracting the Seeds

Physalis berries are pretty tiny, which can make getting the seeds out a bit of a project. Start by slicing the berries in half, then use a small stick or a toothpick to scrape the seeds out of the skin. You’ll notice a lot of sticky pulp clinging to them—don’t worry, that’s normal! The best way to clean them is through fermentation. This process actually helps the seeds germinate faster when you plant them later.

How to ferment your seeds:

1. Place the seeds and pulp into a small glass.
2. Fill it with lukewarm water.
3. Add a pinch of sugar to get things moving.
4. Let it sit in a warm spot for 2-3 days.
5. Pour the mixture into a fine-mesh sieve and rinse thoroughly with water.
6. Rub away any remaining bits of pulp.
7. Leave the seeds in the sieve to dry in a warm place.

I like drying them right in the sieve rather than on a paper towel. It allows air to circulate from both sides so they dry faster, and they won’t stick to the mesh like they do to paper!

Storing Your Seeds

Once your seeds are bone-dry, you need to store them properly to keep them viable and mold-free until next season.

Pick a spot that is cool and dry—ideally under 60°F (15°C). Paper envelopes or small cardboard boxes work great because they breathe. If you prefer an airtight container like a glass jar, just make sure both the jar and the seeds are completely dry before sealing them up.

When stored correctly, Physalis seeds can stay good for several years, so you’ll be set for many harvests to come!