Here is South Florida, they are very invasive. The seeds are distributed by birds who eat the fruits and then defecate them around our neighborhoods. They grow very quickly, and although they are quite easy to pull up when very small (I'd say up to about 8 inches), they are extremely difficult to pull out if you let them get 1 or 2 feet. To my experience, they have intensive root system: I was digging out and fixing the area behind my fence, in the alley near my oak tree, when I found a shallow root that needed to be removed. I started to pull it out, and it took me all the way to the other side of my yard near my Carrotwood tree, I'd say at least 50". The root is pretty, and orange: I'd say a crafter would find some good use for it. But that is besides the point. Our whole neighborhood is infested by this tree species. It is shifting and damaging fences, it is taking over hedges. I quite often find Carrotwood seedlings trying to grow near the base of my oak tree. I quickly remove them as soon as I see them. There is no weed that draw immediate action from me, as does the Carrotwood seedlings. I would definitely do yourself and your neighbors a favor and cut it down . I have yet to deal with mine. Simply cutting it down won't do because it will sprout up again from the stump. I really like trees, so it is hard for me to say destroy a tree, but for this tree I make an exception. I hope this helps.
