Hi all,
I only ask as I recently got some and after about a week or so they are growing shoots??
I don't think it matters, I've got some Green Alder
Alnus cordata cones that I've collected recently, and they are also growing seedlings in the tanks. I've had it happen before with Common Alder, but this doesn't seem to happen if you collect the cones later in the year, so I assume it is because the scales are still closed, and the seed hasn't fallen out yet.
You could try drying the cones for a couple of days, my suspicion is that the all the seeds will then drop out, and the cones will be obviously open.
cheers Darrel