I didn’t enjoy school at all. In fact, I would say my school days were terrifying. I spent five years at Templeogue College in Dublin but I was quite lazy, absolutely bored most of the time and I never arrived at school with any homework done. Mr Weafer, my art teacher, was an inspiration to me because he had exactly the same attitude.

He didn’t do the usual things that teachers do. He didn’t go from class to class with books under his arm, shouting at pupils in the corridor; instead he would relax in his art room and let me mess around with pottery, not minding if I skipped classes. I think I liked the fact that he was so irreverent; it just didn’t fit with the other staff there and made him so appealing.

Art was a great refuge for me. Apart from bluffing my way through religion, it was the only other subject I enjoyed and felt I could actually be good at. I became fascinated by Mr Weafer’s chalky drawings and the whole idea of creating something from nothing.

For a small man, he was larger than life, like a cartoon. I think everybody in the school loved him. For me it was his unmistakable accent and the unique way he spoke. He had a slight whistle that emanated from the corner of his mouth when he talked and my friends and I would mimic him all the time. He was such a jovial character though that I doubt he minded a bit of gentle mockery. You got the feeling he wandered around in a world of his own while at the same time carrying himself off in the world he was in and I really admired that.

Nothing was taken too seriously. It’s probably why he was born to be a teacher. He was also good on the history of art and he would take us out of school on trips to museums or landmarks to make lessons fun.

I had an inclination towards art and pottery in particular but I would get a lot of approval from him, which I didn’t get in other subjects even though I was a sort of butter-wouldn’t-melt pupil. Everyone was fairly academic at home and thought the way to success came through books and a steady job, but Mr Weafer broke all those rules for me. He was the only person I came across who was doing something different.

The school didn’t have a garden, even though there was plenty of space for one, so I guess I used his art room as my creative outlet. There is a priest there now who has started growing plants and inspiring others with a love of gardening, but I developed that somewhere else. I picked up the gardening bug at cub scouts.

The Let’s Grow campaign means I get to go around a lot of schools and meet some amazing teachers and kids, passing on a love for doing something new. Having a daughter myself now I think you have to get kids into gardening at a young age and show them that you can have fun learning while getting your hands dirty at the same time.

I will always remember Mr Weafer as a jovial man who gave me a place of refuge. When I saw him again a few months after I left the school, I told him I wanted to be a gardener and he seemed utterly mystified and quite dismissive. Most likely he thought that going into gardening was a bit weird really as it was an unusual career choice at the time. Perhaps it was, but it’s one that I have enjoyed enormously and one he helped me realise.

• Diarmuid Gavin is a gardener, author and television personality. He fronts Morrison’s Let’s Grow campaign, which gives free gardening equipment to schools. He was talking to Dan Clay.