Given adequate rainfall and the right range of soil acidity trees will seed and grow themselves. This town was farm fields in the 1930s. Some trees were planted when the streets were laid out and houses built. Others, particularly ornamentals, continue to be planted. But there are a great number of trees that are volunteers that have been allowed to mature over the last century. Norway maples, sweet gum, tulip poplar, and red oak are particularly good at volunteering.

We have mullberry, maple, boxelder, and sometimes oak trees that spring up everywhere and basically need to be weeded before they get too big. Mullberry is particularly "weedy", a common sight at the edge of fences or in hedges.

I've had health issues for about 5 years, my back yard is a dense forest because I'm not outside editing it back to my preferences.

Trees definitely do not need us.

In a dense cities, the trees you see now that were allowed to grow to maturity were mostly likely planted by a human, with some exceptions of course. Any trees that began to grow organically were probably cut or eliminated.

>Trees definitely do not need us.

Until they do. Eventually bugs and diseases would kill off huge portions of them. Trees would still be around, but it'd definitely be a different mix than we have now. Right now every ash tree in my state is either dead or dying due to beetles, all the chestnuts died when I was a kid, the native oaks mostly only live where they've been planted because anytime one dies a faster growing maple replaces it.

Many do plant themselves. In my city (Atlanta), slash pine, pecan, tulip poplar and mimosa frequently grow as volunteers and get quite large.

This is definitely an odd take, given the 150+ saplings I pull from my meager backyard every spring. I'm still killing off the root system of some Elm trees that were destroyed in 2021 during the big freeze here in Texas. If I didn't keep that in check I'd have dozens of elms at this point.

There definitely is a weird dichotomy between intentionally planted trees and the ones that just randomly show up. Maple trees grow like dandelions here in the midwest.

Hell I've had a little cottonwood tree growing in the corner of my truck bed for 3-4 years. It never gets any bigger but always produces new leaves every spring.

Get one of those fancy scissors, do some pruning and say you're doing this new thing called truck bonsai

Well put.

It's incredible how our minds are unable to grasp timescales greater than a decade. It dawned on me recently. I visited a place that had trees which were roughly my height 10 years ago. It's a genuine forest now.

Trees are perfectly fine with those timescales. Let them be and they will grow.

Another mind-blown moment was when I was visiting a park in Warsaw. Seemed like old-growth forest - little do I know! There was a display nearby which shared, that during WWII, the Nazis cut the park clear because the opposition was hiding in the trees. That was less than 100 years ago.