When my girls were young I wanted to show them the dangers of a dry Christmas tree. We lived in Spring with old growth trees and a much smaller lot than yours. In the clearest part of our backyard, I dropped the tree into 55gal steel barrel and put a BIC lighter to it. Holy FFFF! That thing lit up like a, well ,YOU know! Seriously burnt foliage 20, 30, even 40' up, scarred the bejabers outta me too.I burn my old flags in my firepit.
Christmas trees in my burn pile.