Hi Alana,
They are a PITA to collect. Later in summer, well you are probably ahead of me being more southern, lol, anyway, by then there are a good amount of pods so I take a larger bag that stays open that I can get near a plant and move the part of the plant that is near it so pods explode into it. Another thing you can do is position containers near/under the plants and leave them. Though this isn't real attractive, you will get seeds dropped into them.
Remy

Thanks Remy!
I think I will try the container idea and see if I have any success that way.
Alana

Alana,
How did it go? Did you get seed?
Remy

Not so well, Remy. I have had to be away a lot this summer and it seems like I am always too late. I did set a bunch of bowls, pots and trays around but I guess I should have tried bagging them in spite of their delicacy because I think I collected 3 seeds total. I have not completely given up though-I have some time off in a couple of weeks and I will have a lot of neglected garden chores to do. I may camp out next to Impatiens patch.
Thanks for asking,
Alana

I'm sorry to hear that! Maybe it works for me since they are in a sheltered location and there isn't much wind to carry them any distance.
Hopefully you can get out there with a big bag and collect some.
Remy