noun
frost on trees; hoarfrost on trees
General term for ice crystals formed on trees by freezing fog or moisture. Often used in meteorological contexts.
今朝は冷え込んで、山の木々に樹氷ができていた。
It was so cold this morning that frost had formed on the trees in the mountains.
noun
snow monsters; frost-covered trees
Refers specifically to the dramatic, large-scale frost formations on trees in certain regions like Zao, where they are called 'snow monsters'. More of a tourism and local term.
蔵王の樹氷は「スノーモンスター」として有名だ。
The frost-covered trees of Zao are famous as 'snow monsters'.