Just sharing a seed-grown alder that got its first shallow pot, I think it looks cute. Moss was self-growing on top of previous pot, hopefully they'll move on together.
Not really, we gather loads and loads of seeds from the cones (best while it's still snowy, March-April) by collecting branches that break off on their own in windy weather and drying the cones at home, and just scatter seeds in pots; sometimes something sprouts. Sometimes they just sprout from other outdoor pots if there are alder trees around.