Anyway, Petunias are quite a good thing to grow in the garden, so I do. They flower a lot and for a long time despite drought and poor soil. Years ago, you could have any colour you liked so long as it was purple. Nowadays, you can get white, red, yellow, etc. (My tip: Stick to purple. I've tried red and yellow and they do work but they don't thrive the way the purple ones do.)
For shear performance, don't only choose purple, choose 'Surfinia' hybrids. They're sold in shops and garden centres everywhere. They're often described as "trailing" with the suggestion you use them for hanging baskets but they spread nicely in conventional flower beds too.
Unfortunately 'Surfinia' seeds are not available (and harvesting seeds to use next year is unlikely to work). You can get seeds for other hybrids that grow into quite reasonable plants. I've had some success with F2 hybrids from Wilkinson's
Growing from seed isn't difficult - once you know the tricks.
- For germination, you need warmth. 70-85F is good.I have a room that is normally heated to 25C which works well. Another technique is a heated propagator. These use about 8W.
- Scatter the seed on the surface of the compost, don't bury them.
- Keep them somewhere light
- After germination, you can reduce the temperature to say 65F and plant out after your last frost date.