I have a Bismarkia in my front yard. We had it planted 9 years ago. It was a beautiful tree when we got it and has really grown in the past 9 years. This is the first year we have had seeds on the tree. I would like to pick the seeds, but don't know when. They came out in April and are still green. Some are starting to turn brown. Is it time to harvest the seeds? Any help will be appreciated.