Grow Petunias from Seed for a Beautiful Flower Garden

Last Updated on November 9, 2021 by Real Men Sow

Petunias are the most popular bedding plant in the world since they bloom long and are available in plenty of colors. This flower is a beautiful part of ornamental gardens too.  Tiny seeds are strong germination, however, seedlings need a long head start. Growing petunias from seed need about 10 weeks and sufficient supplemental light. 

How to Grow Petunias from Seed

Its seeds are tiny, however, elite strains are often sold in pelleted form, making it easier for you to handle. You’ll have to sow petunia seeds by gently pressing them into a moist seed-starting mix. Sprinkle a little more mix to barely cover your seeds. If you keep its place warm and moist, your seeds will germinate within 7 days.

Move your petunia seedlings into roomier pots when needed, and treat them like tiny tomatoes or any other Solanaceae cousin. Your plants will be ready to be left out after the last frost date in rich, well-drained soil or roomy containers. You may cut them back by half and feed them with high nitrogen liquid fertilizer in midsummer when they need to be perked up. 

History of Growing Petunias from Seed

Petunias are native to South America, gardeners loved how they were pest-resistant and perfumed the evening air. The Old Fashioned Vining Petunia grow 61cm tall and continue to bloom well in autumn. This petunia shed a generous amount of seeds. Meanwhile the Balcony variety turns vine-like as the plant ages. Over the years, they’ve been crossed-breed and created a variety of petunias.

Growing Fragrant Petunias in Pots

Petunias attract the night-flying months, their preferred pollinators through emitting fragrance at dusk. Over the years, flower breeders prioritized the petunia’s color, making their fragrance less and rare. However, the Evening Scentsation, a lilac blue petunia, is fragrant in the late afternoon and evening. It’s best to grow them in pots, located somewhere at nose level to be able to smell them.


Pricey Premium Petunias

The Wave Petunias are known to be heavy-blooming, however, they’re expensive. They grow clouds or carpets of color when taken care of properly. The Silver Tidal Wave Petunias goes with everything and emits fragrance in the evening, however, its seeds are not cheap and even the plants. The Kabloom Calibrachoa Petunias are expensive as well, and popularly grown as mini-petunias in containers. 

If you live in mild winter climates, your container-grown plants of premium petunias can be trimmed 15cm in autumn. They can be held through winter in a semi-dormant state in a heated protected space where they will not freeze. In spring, your plants will start regrowing. This is the time where you can root 10cm long stems in moist seed-starting mix to increase your supply of plants.


Real Men Sow
Real Men Sow

Hello, I’m Pete and I’m currently based in the west of Scotland, in a small place called Rosneath, where I’m exploring my garden adventures. I personally started gardening around 6 years ago and initially, I started out by growing my favorite fruits and berries, such as strawberries, Raspberries & Gooseberries. Since then I’ve added a lot of vegetables and working closely with my neighbor, it’s been a lot of fun.