From Easy Going Scans:

Sul is a gardener living in the heart of a city - a veritable concrete jungle. He is an avid gardener and his yard is filled with rare plants which he tends with loving care. The townsfolk object to his practices, claiming that the plants are 'dangerous'.

One night, his garden is ravaged by a sudden, intense fire. Sul, who was blinded in the blaze, is hospitalized...and promptly lapses into a coma. While his niece anxiously awaits his revival, Sul finds himself trapped in a world full of many and varied trees; the likes of which he had never seen before. A world that, at first glance, appears to be his ideal utopia. But he soon discovers that there is unmistakeable cruelty lurking beneath the facade of beauty and tranquility...

Original Webtoon