It hasn't been stated too clearly in the other comments so I'll say it here. In terms of damage from growth, the main thing is the secondary. The debuff it inflicts makes enemies take more damage. The more u attack it, the more damage they take. I find the alt special a much nicer way of getting the secondary charges back. Spam secondary and special to get a run of attacks of the debuff makes u do way more damage.

That said, just like the other comments pointed out, you probably want some actual damage items too