One more magic event takes place on St. John's night: the fern blooms. Country people, accustomed as they were to various natural phenomena and familiar with the flora around them, knew that all plants began from seed. They grow, bloom and produce fruit or seed, thus propagating themselves. Everyone knew that mushrooms had no seed (at least this is what people believed in), but mushrooms were not really "plants". They were almost magical suddenly popping up from the earth after a rain and just as suddenly vanishing. Small children and slightly simple-minded adults were teased and sent "to bring back or buy mushroom seeds"

But the fern was another matter. The plant was luxurious, green, it grew everywhere, especially in forests and damp fields: it was like other local plants though no one had ever managed to find fern seeds or see its flower. How did it propagate then? Therein lies the belief that the fern blossom is miraculous. The plant blooms at the most magical time of the year, St. John's night. Whoever finds that flower is able to understand the language of birds and animals and all the tongues of the world; he knows what others are thinking, where fortunes are buried and is able to see Death (he can tell who will live and who will die). These properties of the fern blossom are known not only to humans but to witches and all demonic creatures as well. They make every effort to seize the fern blossom for themselves. If a human sits among the ferns waiting for them to bloom on that night, the spirits, demons and witches use various methods to frighten and entice him to divert his attention away from the fern. As soon as the human glances away, the fern blossom opens and a specter seizes it. There are stories about a man on St. John's night crossing a forest where fern grow and accidentally finding a fern flower: the flower falls into his boot. Suddenly everything brightened, the man was able to understand the language of nocturnal birds and animals and even hear what the fireflies whispered to each other. He knew he had found the miraculous fern blossom!

The stories usually end with the man sitting down to rest and removing his-footwear - the magical flower fails out and all the miracles end.

The fern's bloom is like a shiny, sparkling red or rainbow-colored light. It opens at exactly midnight on St. John's night. The flower can be plucked if a circle is traced around the fern clump with a mountain ash stick (for the mountain ash — Sermuksnis is a magical tree feared by evil spirits and witches. They can be warded off with a mountain ash stick) or any blessed silver object. Sit inside the circle and absolutely forever move your eyes from the fern regardless of what happens around. The fern only blooms for a twinkling of an eye. As already mentioned, spirits and witches try to distract the person's attention. It appears they are always successful, for a human has yet to find the flower of the fern.