Congratulations, you found out what DnD actually stands for: Damage and Damage. Everything that helps you deal more damage is cool and innovative and everything that doesn't deal damage is just a waste of time.

But here comes the problem. Your fertilizer bomb is extremely effective at doing the only important thing in the entire system. So why don't you use it every time against all of the enemies?

Your DM has two choices if you decide to do that: Either block you from doing so which will almost always feel forced or use enemies with bigger hp pools which is effectively a debuff to all other character abilities. Either way sucks. Welcome to DnD!