ok so i have an orange dandilion growing it is not even mature and it has rank 4 exploding knats if this has happened to you i need to know how to get rid of themplease help
Unfortunately, you will need to get to MooShu and spend a ton of gold to train for the Flyswatter pest spell. It costs tens of thousands of gold. (I think it's 25,000 gold!)
This is one area where KI didn't really plan things out very well. You can get to high ranks in gardening much faster than you can get to the worlds where high-rank gardening spells are available (or affordable).
If you can't afford the Flyswatter spell from MooShu (or you can't even get to MooShu), I agree that you will probably be better off to just let the orange dandilion wilt for now. If you don't need that pot or patch of ground, you could try to leave it in a wilted/dead state and see if you can revive it later when you can get the Flyswatter spell more easily. Otherwise, just dig it up and don't plant any other Rank 4 plants until you're much further along in the game and can get to MooShu (around level 35).