Well, yes, it could be. It depends whether he knew how much you were enjoying the flowers and deliberately ruined your pleasure.
More likely: "It's called gardening" is certainly the kind of response that sounds like it could be part of a pattern of abuse - belittling you, dismissing your sadness, gaslighting you that nothing has happened to be upset about, and that you are the one in the wrong because you don't understand these basic adult responsibilities. An inability - or refusal - to accept that he's wrong and it's had an impact on you.
If it were you, and you genuinely thought you were doing the right thing, what would you have said?
Maybe 'Oh no, I thought it was looking a bit overgrown so I clipped it - I didn't realise it would upset you, really sorry DH'.
Or if you genuinely thought you knew what you were doing you'd say 'oh yes I know it's a bit brutal, but it has to be done or [reason for doing it]. And then when he said 'no, you prune after flowering, look, here's what google says' you'd say 'oh god, sorry DH, I've been a twat.'
You wouldn't say, effectively, 'DH you know nothing about how to deal with this because you are a child in this respect. I am doing what needs to be done, stop snivelling and be grateful.'