Starting Petunia seedlings/Help

[lonewolf]

For two years, now, I have been trying to get petunias started from seed and have failed, miserably. I buy the seed from a nursery and have tried everything from the Waves to the standard singles.
The seeds are so tiny and the instructions say to merely sprinkle them on the soil, which I do. They will sprout, grow two tiny leaves and that's as far as they grow. They will just sit there, like that and eventually die.
Does anyone know what I am doing wrong?
One thing I didn't do, which may be a problem, is I didn't start them in seedling mix, but rather in a good potting soil.
But they did sprout, so not sure.
Does anyone have a clue what I maybe doing wrong?
Could they not be warm enough in the GH. It doesn't get below freezing.

[Tig]

The seeds are like dust and are a challenge to sow thinly. I tend to surface sow them in March on a very fine sowing compost and water from the bottom, keeping them at a temperature of around 20-25c. If they are too thickly sown they tend to damp off before they get growing well. Also, once they have germinated I find they do better if subjected to some temperature fluctuations (12-15c overnight, back to 20c in the day), and not kept in direct sunlight but in good light. If the seedlings are too close together you need to thin them out into trays with individual sections as soon as they have 3 true leaves.

And if they all fail .... I buy some more from the Garden Centre or local market

x Tig

[lonewolf]

Dec 12, 2012 23:52:27 GMT Tig said:

The seeds are like dust and are a challenge to sow thinly. I tend to surface sow them in March on a very fine sowing compost and water from the bottom, keeping them at a temperature of around 20-25c. If they are too thickly sown they tend to damp off before they get growing well. Also, once they have germinated I find they do better if subjected to some temperature fluctuations (12-15c overnight, back to 20c in the day), and not kept in direct sunlight but in good light. If the seedlings are too close together you need to thin them out into trays with individual sections as soon as they have 3 true leaves.

And if they all fail .... I buy some more from the Garden Centre or local market

x Tig

Thanks. Each pack contains only about 20 seeds and I scatter them on a 10 x 10 flat, so they aren't crowded. I water from the bottom and most all seedlings germinate. They just don't grow once they germinate. I have a lot of diffused light in the GH and temps. are like you describe.
I keep thinking it's the wrong soil, but can't see why it would make such a difference, especially if they germinate.

[Tig]

I use seed and sowing compost for starting most of my seeds off. There are minimal nutrients in it which seems to make them stronger when small, then they get better compost once they are potted on. The best advice I can give on successfully germinating and growing any seed is to research what conditions the plant has in the 'wild' - if you can replicate this then chances of getting good results are greatly improved.

Sowing and growing from seed is a passion for me, I like to try something new every year

x Tig

[Rosefriend]

I am doing Petunias for the first time again since a few years - I always had problems, thanks for the tips Tig..

However once thing that always annoyed me was that the seeds would fall on the terrace in the summer, germinate immediately and grew until the frost got them...I was often tempted to try and ease them out from between the slabs but overwintering them would have been a large problem..

RF

[lonewolf]

Yes, thanks Tig. I just placed ANOTHER order for more Wave seeds and will try again using a mix for seeds. Fingers crossed.
Rose. I too will get volunteers sprouting up in the concrete cracks, but can't seem to grow the fancy ones from seeds. I'm thinking we would kill them trying to get them out. I just leave them. I have them growing in the cracks and rocks of my Koi pond.