Nope, Kanji didn't know much about grass types or the like. As far as he knew, plants didn't have sentience or personalities or anything. They were just things that did photosynthesis. The end. However, it wasn't unheard of for someone to get attached to their plants, so Kanji could sort of see where Bulba was coming from.

When he mentioned the fertilizer, though, he had to crack a smile. "Seems like it'll suit him the best."