Does anyone know a way to preserve the 'helicopters' so that they stay green? I've tried nail polish and waxpaper but neither works (the helicopters turn brown). I'd appreciate any ideas.

Does anyone know a way to preserve the 'helicopters' so that they stay green? I've tried nail polish and waxpaper but neither works (the helicopters turn brown). I'd appreciate any ideas.
I'm not sure it's possible, but you might try a clear varnish or polyeurethane.

I am wonedring why you would want to do this. Most folks are asking us how to kill them and you want to preserve them. It can not be done, the green is the seed is trying to germinate and if it doesn't get enough water it will die and turn brown. Give it water and it germinates and won't be green once the roots use up the stored "food" in the seed.

I don't know if this will work but we used to mix half glycerin and water to preserve eucalyptus branches. Since water might make the maple seeds germinate, you might just use the glycerin by itself. You won't want to make a big bunch because it was sort of pricey the last time I checked. Glycerin can be found at your local pharmacy.