It looks like an Oak but it would not seem possible for them to grow that quickly and produce acorns???

Well that would certainly make more sense... duh.

are you afraid of it.. we need a close up of a leaf.. and a seed pod.. to confirm the ID .. though they sound pretty certain ...

ken

That is a pretty woody structure for a datura (jimson weed), an annual plant. Usually these are smaller, more ground-hugging herbaceous plants that seldom achieve much more than a foot or two in height before being killed back to the ground by frost. I'd want to see closer images of the leaves and seed pods before confirming.

Datura (jimsonweed) has spiky seed pods filled with small black seeds. The plant in question looks to have the pods as well as the growth habit. It probably was self sowed.

Few trees could grow to that size AND flower and go to seed in one season from a seed (in fact, I know of none). It's an annual.

It's a Datura.

Here's a few close ups. The garden is in the back of the school and was untouched since May. Appreciate all the input!

It sure is a Datura. Those pods need to be removed before you pull/dig it out or there will be more of them growing there.

Hundreds of seeds are waiting to spill out of the mature pods.

I've been reading up on this plant and it has me worried. I want to remove it immediately but do I need to take any special precautions? Should I ask a landscaper/professional to do it?

Also should I have the soil removed?

As long as you don't ingest the plant you'll be fine. Just try not to spill the seeds or get pricked while getting it out. Other than seedlings from the seeds dropped by the plant the soil is unaffected and perfectly fine. Pull any seedlings that come up.