Hi Alice,

I have never collected them myself, but came across this post.

* Posted by remy 6WNY (My Page) on
Mon, Aug 25, 08 at 23:17

Hi,
You should leave them on the plants until they turn brown. Picking earlier lowers the germination rate greatly.
They may vary in size. That they are hard and not easy to crush is more important.
Remy

Sue

I'm collecting my own for the first time right now as well. All the ones on the plant are still green, and the brown ones are down in the dirt. Here's another blog post I found about it: http://mrbrownthumb.blogspot.com/2007/08/when-i-collect-nasturtium-seeds.html