Wait- before you get Non-stops, is your "part sun" morning sun, afternoon sun, or dappled all day? For me, Non-stops do beautifully in morning sun. When I tried them where they were shaded most of the day with afternoon sun, they fried. Depending on your conditions, the various new Begonia boliviensis hybrids may be a better choice. They are also tuberous, but they can handle more sun and heat. The "Bonfire" series has been out for a while and comes in three bright colors. They can get spectacularly huge, but are trailing so they wouldn't be top-heavy. There's a newer series called "Crackling Fire" which stays smaller and bushier, and comes in more colors. I think "Crackling Fire" might be the right size for your planter boxes. I haven't tried them yet but was tempted by them at the nursery. And yet another series called "Million Kisses," which I've only seen in catalogs so far. And there's a seed-grown variety that looks similar to "Bonfire" and might stay smaller. "Santa Cruz Sunset" only comes in red-orange. I grew 6 from seed last year, which made one hanging basket because they were babies. You'd want to buy them as started plants. Seeds have to be sown by early February to have plants for summer. The nice thing about tuberous begonias is that if you have a good spot to store them and ignore them over winter, you may be able to keep the same plants for years. They get larger each year. My "Santa Cruz" basket has revived and should fully come into its own this year. Might need a bigger basket. :-) Oh, and I almost forgot. DragonWing has a smaller sibling, BabyWing. They only come in white or pale pink. This post was edited by edie_h on Sun, Apr 27, 14 at 3:13

I agree with Al completely... They would need a significant hardening off process, and if your Z8 is like this Z8 where the weather can be unpredictable into March, there is the chance you would need to move them someplace protected depending on the forecast for your area - which you would watch. I've sown them late summer/Fall and left them outdoors - germination takes place then in late winter and those seedlings which have germinated outside will withstand my late winter frosts.

I also have no experience with growing these type of begonias; just received 6 tubes and they have sprouted the little pink sprouts. Now, don't laugh to hard but is this little pink sprout a leave sprout or a root sprout... which ends up??? So pink sprout up or down??? Thanks granny

I think that is too little a pot for even wax begonias. Give them more soil and some nourishment (I water mine with horse poop tea.), and I think they will take off for you. As far as storing over the winter, I never get mine in soon enough to offer any advice there. I've got to stop buying plants that have to be dug or brought in for winter. This last winter is the first year I have ever got my cannas in before the hard frost. I have a friend who tells me that the solution for my sloth problem is to plant the begonias in one of those hanging sacks. That is what she does. She takes it down and lays it on the ground to water it thoroughly with the hose. She also applies her liquid fertilizer like that. She has gorgous begonias and she just brings the bag in in the winter, hangs it in the basement and stops watering until March the next year. Carmellia