Last night there was an air frost in the garden and a thin skin of ice in the morning on the Wbx pond. The Japanese maple leaves are expanding fast and I fear this sudden knee-jerk cold may well kill such tender shoots. They look okay at present, but this can be deceptive.
So, I have photographed them while they still look in good condition. An interesting feature is that these second year leaves are a different shape than those of the first year (see smaller picture) and much more like traditional Japanese maple leaves.