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Get more bang for your buck by growing petunias from seed instead of buying flats at the store! Learn how to grow petunias from seed here!

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What do petunia seeds look like?

Petunia seeds are tiny, black specks that are difficult to handle.

How to start Petunias from seeds

Starting seeds indoors

Use a good quality seed starting mix, not potting soil. It's specially formulated to be lighter, so the tiny seedlings can push through easily. .

Surface sow seeds

Petunia seeds need light to germinate, so you can just sprinkle them lightly over the surface of the soil. I prefer to use a toothpick dipped in water to pick up each seed to make it easier to place.


With seeds this small, you risk washing them all away if you use a watering can to water them! Mist with a spray bottle instead.

Humidity dome

After watering, place a humidity dome over the tray and use it until most of the seeds have germinated, which usually takes between 7 and 21 days.

Keep seedlings warm

Petunia seeds need to be kept warm in order to germinate. Use a heat mat to keep the soil temperature between 70 and 75 degrees Fahrenheit.


Wait until after your last frost date to transplant petunias. They don't like the cold, and prefer for their soil to be at least 60 degrees to avoid shocking the roots.

Learn more about growing petunias by clicking the link below!