This has more than likely come about by poor sowing techniques or bad compost rather than poor seed performance. Petunia seeds are very small and needs lots of light in order to germinate. Knowing your frost dates can help you decide when to start your seeds indoors. Then, plan to plant it during the ideal conditions. Reliable go-to plants, dianthus (Dianthus spp.) The stunning color of petunias can be the crowning glory of your flower garden. Have you ever wanted to grow your own grapes? If you are wondering how long for grass seed to germinate, you first have to look at the type of grass you selected to grow. Using seeds is a cost-effective way to grow flowers. The seedlings grow slowly and are not ready to plant outdoors until 10 to 12 weeks after sowing the seeds… One of the main reasons people grow plants from seed is because they can choose from a wide variety of plants in seed catalogs. It’s a shame they can’t be permanent. Each 1 ounce of petunia seeds contains approximately 250,000 to 300,000 tiny seeds. Place your seeds in grow cells. Give Them Plenty of Light. A soil temperature (not room temperature) of 75 degrees F is perfect. The most important point to remember when learning how to start petunias from seeds is that these are summer, heat-loving plants. It does them no good to plant them early in the garden, as they’ll just sit and sulk or rot. Some seed may take a little longer. A petunia plant is an annual flower that is difficult to grow from seed due to its small seed size. We supply petunias in several plug plant sizes, but there’s a real sense of satisfaction in growing a show stopping summer display of petunias from seed.. Somewhere along the line, petunias have gained a wrongful reputation of being difficult to grow from seed. 2. Growing Wave Petunias from seed. Be careful to sprinkle the seeds on top of … Germinated petunia seeds will present sprouts seven to 10 days after planting. The viability of petunia seeds makes them ideal for propagation purposes. Petunias need to be started from seed around 10-12 weeks before you want to plant them outdoors. Remember to water them. Start Early. One of the economical ways to fill your garden with Wave Petunias is to grow your own plants from seed. In order to get these seedlings to planting size at the right time, you need to start them indoors at least 10 weeks before planting time. and petunia (Petunia x hybrida) have a lot in common. When you’re wondering how long do petunias last, you might be considering two different things. You can harvest these seeds on your own, and use them for next year plantation.