I am trying to harvest California poppy seeds to be used next year. Living in Northeast Ohio, the tendency for these plants is to be an annual. Presently (late October) I've got lots of green seedpods, but can't find any that have become brown. I "think" I need to harvest what ever seeds or seed pods I can get before frost/freezing/snow hits the area, however I can't seem to get a clear idea if I should wait til the pods (still on the plant) turn brown and are ready to "pop".

Can I take remove these green pods (with a bit of stem) and let them dry and mature in a dry (garage or basement) to harvest viable seeds for next season?

  • I would leave them on the plant until they turn brown. I've definitely seen brown seed pods on poppies in Northeast Ohio. You could sacrifice one pod by cutting it open to see if the seeds look mature, but I'm guessing it will be hard to tell because poppy seeds are so small.
    – csk
    Commented Oct 30, 2020 at 18:12
  • I've been watching a couple of specific pods that have been about 4 inches long for over a month, no browning seen yet. I would have thought the pods/seeds would have matured by now. Have any idea how long maturity might take after pods get that long?
    – BobE
    Commented Oct 30, 2020 at 18:24
  • Oh, I just realized California poppies (Eschscholzia californica) are different from "regular" poppies (Papaver sp). I found this site that says California poppies love to reseed, so perhaps just leaving them as is and letting the seeds drop naturally is the best course. That article is about Ohio, but it's not clear if they actually know for a fact that California poppies will reseed in Ohio.
    – csk
    Commented Oct 30, 2020 at 19:29
  • Ive grown these in the UK, where they are only annuals - I never bothered to collect seed, I found seedlings used to pop up all over the following spring, and I'd just remove the ones I didn't want. They popped up every year for 10 years all on their own...then I moved house. For all I know, that garden still has loads of them...
    – Bamboo
    Commented Oct 31, 2020 at 12:36

1 Answer 1


This USDA planting guide for California poppy has this information about seed collection, storage and planting (emphasis mine):

Through the domestication process and the selection of horticultural traits, most complex seed dormancy requirements for garden variety California poppy have been reduced or eliminated. Domesticated California poppy seed germinated consistently... Any remaining seed dormancy can generally be overcome by sowing seeds in the fall as day-length decreases in locations with mild winters, or seeds may be sown in early spring in areas with harsh winters.

So as long as you grew your poppies from a seed packet or bought them at a garden center, they should be pretty easy to propagate from seed. That means you don't need to cold stratify the seeds, or treat them with smoke or acid or any of the complicated methods that can be necessary for some plants. (But if you grew your original plants from wild-harvested seeds, you may have to work harder to to convince them to germinate. See the planting guide I linked to above for details.)

Regarding seed storage:

Seed may be relatively short-lived under room temperature storage, perhaps maintaining viability for about five years

This article has good photos and detailed instructions for harvesting seeds. They show what the mature seed pod look like, and how to distinguish mature from immature seeds. Mature seeds are brown; immature seeds are green. The mature seed pods turn brown and develop long grooves down the side as they dry out. The author is based in California, so it's not clear from this article whether the seeds will mature on the plant in the shorter growing season of northern Ohio.

Here's what the seeds look like inside a mature seedpod:

enter image description here

This growing guide from Cornell University says,

This plant may seem like it is a perennial, coming back in the same place every year due to self-seeding.

Which implies that it may self-seed without any assistance from you. The Cornell guide doesn't specify what region it's for, but presumably the advice would at least apply Ithaca, NY where Cornell University is located. Ithaca has a similar climate to northeast Ohio, if anything slightly colder and snowier. So it seems fairly likely that your California poppies will self-seed without any effort on your part.

https://www.gardeningchannel.com/how-to-grow-california-poppy/ http://blogs.oregonstate.edu/gardenecologylab/2017/11/14/plant-week-california-poppy/

Based on the information I found, my recommendation is to hedge your bets by treating the seed pods in 3 different ways:

  • Harvest 1/3 of the seed pods before the first frost, even if they're still green. Put them in paper bags, loosely spaced so they can dry out.
  • Leave 1/3 of the seed pods on the plants until they turn brown, however long that takes. Once they're brown, harvest them and put them in paper bags.
  • Leave 1/3 of the seed pods on the plants all winter, in hopes that they self-seed.

Store the seed pods you harvest indoors in a cool, dark place in paper bags. Clearly label the bags so in the spring you will know which ones you harvested early and which ones you harvested late. The pods may pop open and release the seeds into the bag, so be sure to close the bag fully and use a bag without any holes. In spring, plant the seeds after the first frost. Sow them shallowly, 1/16" deep or just scattered on top of the soil and maybe covered with some straw to stop birds from eating them. Plant the early-harvested seeds in a separate place from the late-harvested seeds, and plant both away from the original plants, so you can see which method is more successful.

  • Great answer, especially liked the 3 pronged experimental approach. What I'm trying to do is to establish an additional colony elsewhere on my property. And yes, the original seeds were purchased commercially. What is puzzling is that this late in the season, I would have expected to see the remains of burst pods on the ground. As carefully as I have inspected the ground debris I've yet to find any of the pods that should have "popped" earlier this year. Thanks again and good weather to you
    – BobE
    Commented Oct 30, 2020 at 21:32

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