Hmmm, well that's odd because you say the other seedlings are growing well. The only thing I can think of is how far away are the fluoro. lights. I normally keep mine about 2-3 inches above the top of the plants and adjust the height of the lights as the plants grow taller (have a hook and chain set-up -- not fancy but hey it works). You could try setting them out in the sun during the cooler weather (but harden off over a period of days - see my reply to Dave from Michigan's post) to see if that helps, but keep in mind impatiens prefer warm conditions so not sure if outside during this time of year is the best idea. Might be worth a try to see what happens, though.

I've collected and grown plants from both. Yes; the imaptiens should have light brown/brown seeds. The white ones aren't ripe yet. If they have snapped off the branches, they weren't. If they were ripe, they would've already popped open when they hit the ground. The ones I've picked have always been still on the branches, and are bright green and fat. I usually collect them by snipping off the branch the pod is on, and then gently put them into a cup, which a lot of times enough to pop them open. They aren't called 'touch me nots' for nothing! As for the begonias, definitely let them get nice and brown until they are practically falling off the branches before gathering. Then, dry them well and store them until you are ready to sow, sometime in early winter. Mind you, I've only gotten a few plants from many pods. They are indeed dust size, and very tempermental. I rubbed the pods gently over the soil and hope for the best, but germination is slow and really tiny. But if you do get some to germinate, be patient and you will be rewarded with beautiful plants that are tougher than the store bought ones. I put mine out in the winter sun on a windowsill and they never burned in the summer sun.

The fruit are green and bladder shaped which pop when you touch them. The seeds are small, flat, tear dropped shaped and brown. You can collect them by poping the fruit in a bag or envelope. Store in a cool dry place.

When the flower drops it off, it will develop a small pod, much like balsam, if its ripe it will burst open when you touch it, the seeds have to be brown to be ripe, not white. Around this neck of the woods, the pods will start forming in late summer, early fall. Not every variety of impatients does set pods though, but I know the red ones do and so do the white. Another way to propigate them is to cut them back, set the stems in water, they will develop roots. Good luck. Alberta