On Saturday Carina went on an Aspen workshop run by Peter Livingstone of Eadha (Gaelic for Aspen). She was so inspired that the next day we went to a stand near Ferry Wood and took some root cuttings, which she is growing on.
We are doing this because Aspens in the Highlands of Scotland are rare now, being unable to set seed naturally. We have a stand of dozens of them on the edge of Ferry Wood, but all are actually clones of each other.
We took cuttings from a nearby stand (also on the edge of a wood) which we had spotted the previous May. The leaves had just come out and were a curious copper colour, so we could spot them from a long way away.
Peter is hoping that because of the hot summer of 2018, aspens might flower again this year, so we will check the various stands we are aware of to see if catkins are produced.
Aspens are easily spotted once their leaves are out, for they tremble and flutter in the slightest of breezes (the poplar family in general does this – but poplars tend to be planted by roadsides, in parks and urban settings).
Aspens are part of our Resilient Land project (RL). RL is about biodiversity and the aspen is an important part of this, with many plants and insects depending on them.
bioregioning 
Delighted to see Ferry Wood a few weeks ago. My wife and I have a 5 hectare organic farm in North Wales and are beginning the rewilding process (inspired by Isabella Tree’s book}. The trembling aspen is indeed a wonderful tree which no longer exists where we are. Any chance of a few small cuttings since, as you say, they don’t set seed and are all clones?