How to Harvest Sweet Pea Seeds

Sweet peas (Lathryrus odoratus) are vintage charmers that are as lovely and welcome in the garden today as they were when Grandma planted them decades ago.

In addition to offering a rainbow of hues and an alluring fragrance, sweet peas also generously self-seed, so if you’re looking to expand your existing patch, just let your plants go to seed, and you’ll be set.

A cluster of pink sweet pea flowers in bloom.

However, if you’d like to gather the seeds to plant in a different place or to perhaps share with a neighbor, read on to learn how to harvest and store these orbs of new life.

How Do You Collect Sweet Pea Seeds?

Identify a few particularly attractive plants you would like to duplicate. Keep in mind that only heirloom varieties will reproduce true-to-type.

Seeds from modern cultivars won’t likely produce the same type of plant from which they came. But maybe you’re a gambler and would like to see what Mother Nature comes up with!

Pink sweet pea blossoms. Close up.

When you’re out in the garden deadheading, ignore the plants you have “set aside.” Allow the flowers of those plants to fade and die while they’re still on the plant. The petals will fall and seed-containing pods will form.

When Do You Harvest Sweet Pea Seeds?

Now you really have to pay attention to them carefully. You’ll notice the pods will transition from light green to a darker green and swell up as the seeds mature inside. When the seeds reach full maturity, the pods will turn a light brown color.

Pluck the pods at this point. If you wait too long, the pods will split, spewing their contents far and wide, and you’ll have lost your opportunity to harvest.

Sweat Pea Seed pods in various stages of maturity on a white, isolated background.

Once you’ve collected collected your pods, bring them indoors and allow them to dry on a rack for a few days to a week. You’ll notice the pods starting to pull open at the seams on their own. Encourage this by running your nail along the seams, and gently press the pods’ contents into a container.

Alternatively, you can place the pods in a paper bag, seal the bag tightly, and put it in a warm place, such as a windowsill. After a couple days, begin shaking the paper bag vigorously to break open the pods and release the seeds . Do this once a day for about seven days until all have been released.

Try this Trick

If all this waiting and watching is not your style, consider purchasing some small muslin bags such as these from Pangda US, available via Amazon, and tying them loosely around each stem, above the pea pod.

Pangda 100 Pieces Drawstring Cotton Bags Muslin Bags

When the pods split, the bag will collect the seeds.

Spread the contents of the bag on a baking sheet and ensure the seeds are completely dry.

Pick and Store

Pick the seeds out and store them in an envelope, such as one of these from Seed Needs via Amazon, or in a lidded jar. Place in a cool, dark place, such as a cellar or refrigerator. Be sure to label and date your container!

Set of 50 Proterra Self Sealing Seed Envelopes

Come springtime, you’ll be ready to plant and enjoy this lovely vine in a new part of your garden.

How Long Will Sweet Pea Seeds Last?

Sweet pea seeds should remain viable for 2-3 years if properly stored.

Sweet pea seeds being inserted into an envelop and dried empty pods.

Harvesting sweet pea seeds is as simple as letting the pods mature on the vine until they’re ready to pick, letting them dry out, and storing.

Have you ever collected sweet pea seeds? Share your tips and secrets in the comments section below! And see a complete guide to growing sweet peas here.

© Ask the Experts, LLC. ALL RIGHTS RESERVED. See our TOS for more details. Uncredited photos: Shutterstock.

About Gretchen Heber

A former garden editor for a daily newspaper in Austin, Texas, Gretchen Heber goes through entirely too many pruners and garden gloves in a year’s time. She’s never met a succulent she didn’t like and gets really irritated every 3-4 years when Austin actually has a freeze cold enough to kill them. To Gretchen, nothing is more rewarding than a quick dash to the garden to pluck herbs to season the evening meal. And it’s definitely time for a happy dance when she’s able to beat the squirrels to the peaches, figs, or loquats.

5 3 votes
Article Rating
Notify of
Newest Most Voted
Inline Feedbacks
View all comments
Gina (@guest_5045)
1 year ago

I harvest sweet peas every two days but when the stems start getting really short I let them go to seed. I try to note the variety but I end up mixing all the seeds together for storage.

NancyL (@guest_9388)
2 months ago

This year will be my first to harvest the seeds. It’s exciting and I’m looking forward to next year’s sweet peas!

Mike Logan
Mike Logan (@guest_9826)
1 month ago

How long between harvesting the seeds to being able to plant the seeds? In Australia (winter) I have just grown SP and they are seeding now (early Sept). But it says to plant in spring which is now Sept to Nov. Reply by email also if possible Thanks

Kristina Hicks-Hamblin
Kristina Hicks-Hamblin (@kristinahickshamblin)
Reply to  Mike Logan
1 month ago

Hi Mike,
In places with mild winters these can be sown in either spring or in fall.

You don’t need to wait before planting your seeds, but you’ll get better germination if you soak them in cold water for 24 hours.

You might want to review our article on growing sweet peas before you get started – and take into account that these plants need 50 days of cool weather before blooming. If you won’t have cool weather for that long, you may want to wait until your next fall season.

Hope this helps!