Three previously unpublished artworks by JRR Tolkien are to be displayed for the first time as part of a major exhibition coming to the University of Oxford’s Bodleian Libraries this summer.

The three pieces will be among rare paintings and drawings by the author of the fantasy masterpiece The Lord of the Rings, reflecting the fact that his literary genius extended to his visual imagination.

The unpublished material was released to the Guardian by the Bodleian in advance of Tolkien Reading Day on Sunday, held on 25 March each year, organised by the Tolkien Society.

The artworks include a Japanese-style delicate drawing of bamboo from the 1960s. Its title Linquë súrissë is in Quenya, one of the highly developed Elvish languages that Tolkien created. It translates as “grass in the wind”.

There is also a black-and-white 1950s abstract bearing Elvish lettering that may have been a book cover design, and an abstract painting from 1914 from his years as an undergraduate at Exeter College, Oxford.

Catherine McIlwaine, the Bodleian’s Tolkien archivist, said of the three artworks: “They don’t relate to his fantasy works directly, but two of them have the Elvish text on them, which links them directly to his writings on Middle-earth, the imagined world where The Lord of the Rings and The Hobbit were set.”

She described the image as “very intriguing”. “It looks to me like a book cover design … Whether he was thinking of creating a new work or whether this was an artefact from Middle-earth, I just don’t know. There’s nothing else like it, and there’s no indication of what it might refer to or what he was thinking. That’s [one] for future scholars.”

Tolkien, who taught Anglo-Saxon at Oxford University, designed it on the back of an agenda for a Merton College meeting dated 26 November 1957, two years before his retirement. The success of The Lord of the Rings had exceeded all expectations and he spent his retirement in Oxford re-working The Silmarillion, his earliest work on the legends of the elves.

As the exhibition will reflect, Tolkien was an accomplished artist, with hobbits, elves and wizards sparking his imagination in words and pictures. Among other illustrations for The Hobbit, he designed the cover for the first edition of 1937, showing stylised mountain peaks, through which hobbit Bilbo Baggins travels on his adventures.

McIlwaine said the three unpublished artworks were all quite different. “You wouldn’t look at them and think ‘that’s Tolkien’, as you might with his watercolours. They show that he was always experimenting with his artwork. He wasn’t afraid to try totally new styles.”

The Bodleian Libraries boast the world’s largest collection of original Tolkien material, and the exhibition will be further boosted by important loans, including manuscripts of The Hobbit and The Lord of the Rings. Anticipating huge interest in the forthcoming exhibition, the Bodleian is using a ticketing system for the first time.

Tolkien had sold the manuscripts of The Hobbit and The Lord of the Rings for £1,500 to Marquette University in Milwaukee as he approached retirement, and began to worry about his pension.

McIlwaine said: “For the first time, we’re going to have some of those manuscript drafts … together with our amazing collection … It’s really exciting.”

The exhibition, titled Tolkien: Maker of Middle-earth, runs from 1 June until 28 October.