Thank you for the reply JamazingClayton.
I’ve just checked out some pictures of the botanical gardens of the university of Ferrara and it looks like a really lovely place. It seems to have a really rustic and compact look to it , which I always think gives a botanic garden a much more intimate feel to it. In fact the size of the Ferrara garden reminds me of my favourites, El Real Jardín Botánico de Madrid, in Spain which is also fairly small and rustic but in spite of this has an unbeatable charm.
In terms of size , its strange because I cant really summon the same affection for the larger gardens I have visited like Kew or the Eden project in the UK or the garden of Sao Paulo in Brazil as I do for the smaller places. I guess bigger botanical gardens may have much more in terms of things to see however there is a trade off (at least in my opinion) in a loss of the sense of intimacy / aesthetics and stronger feelings of being overwhelmed by the amount of space.