What's the best way to start my annual flowers?

I live in Florida and my plants are in the ground! I did however soak the seeds in water for a few days and some of them actually grew shoots. Then of course I put them in egg cartons and kept them wet. Also putting plastic wrap over container of planted seeds helps retain moisture. I wouldnt sow Zinnia indoors because they do well after all frost danger passes. They also do not transplant well. Soaking and then planting works best for me!

What I do is start the seeds indoors and grow the annuals in the either empty butter dishes or empty green house pots put them near the south window either full sun or partial sun, and let them grow indoors.. following the instructions.. For Wisconsin the Frost Date if I remember right is may 5th.. So as it gets closer to this date on nice days set them outside for the day, then bring them back indoors at night.. althought it is sort of snowing so you do not want to set them out quite yet :) ... The Best bet is to buy them at the greenhouses. I used to work in Milton, Wisconsin's FFA Greenhouse and one of our best sales were selling annuals I do not know where you are at.. but those did well for there.. And If you are not good at starting from seed, Greenhouses all over Wisconsin usually do very well, and you just let them sit outisde for a couple of days to a week make sure they are well watered, then plant them into the ground is how we do it, and we usually haver very nice annuals and perenials that last.. They have to be watered often if they are in that really light peat moss type soil as it dries out very fast... but if its in like potting soil and does not drain fast becareful not to overwater them, as that can lead to root rot. K And W Greenery is also a good greenhouse that sells well, most I know from the FFA and Greenhouse management classes went on to that.... It depends on what you are trying to grow but Feburary or March is when you start them indoors.. depending on which type.. and how long it takes to grow, and go through it's full cycle. I hope that helps some. Cuttings, the entire plant, or the seeds are all startable and there is different types of Annuals too some for Spring, Late Summer, and Some for fall. If you are trying to learn to grew your give it a try with one type of plant... and if you need help feel free to message me.. I'll try to help ya out. - DNatureofDTrain

I don't think there is any reason you can't start sweet peas indoor, although they are hardy enough in my climate that it isn't necessary to coddle them but I know WI is pretty cold. I would start them in a long pot, like a longish yogurt pot so the roots have plenty of room to grow down. I wouldn't think you would need to fiddle with bottom heat, either, and if you soak them over night and nick the skin that will get them off like blazes. Can't help you with the Zinnia though, sorry, I've never grown them.