How to Collect and Grow Petunia Seeds

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Why spend a lot of money on hanging baskets when your petunias have thousands of seeds ready for you for free?

Mother nature is amazing. Just one petunia plant can give you enough seeds for the whole growing season. There is no need to buy petunia plants when you can grow them right at home!

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Seed Type?

There are two seed types.

  • Heirloom
  • Hybrid


If your plant is an heirloom, your plant has come from seed that has been handed down for generations. The seeds from this plant will produce an exact replica of the parent plant the seeds came from.


If your plant is a hybrid, the seeds have been intentionally cross-pollinated with different varieties of a plant to produce a seed that contains the best traits of each parent. When you harvest seeds from hybrids, they will not be an exact replica of the plant you took the seeds from. It will be a mix with different traits.

How to Find the Seeds?

Petunias keep their seeds in a seed pod. A seed pod looks like this image above. This little pod contains hundreds of tiny petunia seeds.

First, you want to make sure the seeds are ready. You will know that the seeds are ready when the seed pod is about to burst open like the photo above. The pod should be brown and crunchy.

Can’t Find Any Seed Pods?

If you can’t find any seed pods that look like the photo above, they may not be ready to harvest yet. Every flower that gets pollinated should produce a seed pod. This can be found where the flower petals die off. When a flower starts to shrivel up, it should be able to be picked off easy and look like this.

Below this picked flower, you will find the seed pod still attached to the plant. If it is still green like this photo below, the seeds are still developing and are not ready to harvest. Keep this on the plant until it turns brown and crispy or else the seeds will not be viable.

Collecting the Seeds

After you have located the ready, brown seed pod, now it is time to collect the seeds. I pick off all of the ready seed pods and place them all in a bag.

Next, bring them inside and lay out a paper towel. You will now crunch each seed pod to release the seeds. Release them on the paper towel.

There will be thousands of seeds! Make sure to do this inside because the wind can blow the seeds everywhere. Each one of these seeds can product a petunia plant.

Let the Seeds Sit Up to About 5 Days

If you immediately sealed these up in your seed bags, there’s a chance your seeds could get ruined from moisture and mold, causing your seeds to be ruined. Let your seeds rest on the paper towel for about 5 days to air dry. After you dry out your seeds, make sure to store them in a cool, dark place.

I pile up my seeds and fold the paper towel so I can easily pour them into a small seed bag.

I use these bags to store my seeds.

Don’t Forget to Label Your Seeds

I use this adhesive paper for my seed labels.

You can hand write on these labels with pen like this.

Or you can print out your label to make it look neat and keep it organized with valuable information.

Be sure to include

  • USDA Zone
  • Planting Date
  • Seed Depth
  • Plant Spacing
  • Row Spacing
  • Germination Time
  • Maturity Date

Store Your Seeds

Once your seeds are bagged and labeled, store them in a dark place. I keep mine in a basic gift box.

They also make boxes specifically designed for seed storage like this

Ready to Plant Your Seeds?

You can always sprinkle your seeds somewhere and see if they will come up, but I always use seed trays.

I use the best seed trays on the market from Bootstrap Farmer . Their seed trays are heavy duty and can handle the weight from the plants.

I grow all my seeds in a room upstairs. Once they are ready to go outside, I have to carry them down the steps in their trays. I have tried other brands of seed trays and they could not handle the weight. They bent and made me lose a couple of plants because they busted and failed. After that, I did some research and saw that Bootstrap farmer trays do not fail and can handle the weight. I will never use any other seed tray again.

I start my seeds in this seed starting mix

Petunias need light to germinate, so do not cover the seeds with soil. Lightly sprinkle the seeds on the top of your potting mix. Make sure to water from below to not disturb the seeds.

Petunias take about 7-10 days to germinate (sprout). They should look like this when they are just popping up.

After about 2 weeks, I give them nutrients.


Once your plant has gotten big enough, its roots will have no where to go. Make sure you transplant it to a larger pot or tray.

If you are growing these indoors, make sure you “harden off” your plants before planting them outside. Continuously bring your plants out in increments of 1 hour each day for about two weeks to get them used to the outdoor environment. Example: Day one-1 hour, Day two-2 hours, Day three- 3 hours etc. Make sure in the beginning days you do not place them in direct sun.

Enjoy Your Petunias Year After Year

Collect your petunia seeds every year and you will never have to buy them again!

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