Minecraft – Does Tree Tubing still work

minecraft-java-edition

I'm trying to tube some trees, to force them to grow large. I planted my sapling in a 1x1x2 hole, but this happened:

enter image description here

Was tree tubing nerfed at some point?

Ok, I've done some research of my own, and the following seems to be the case:

Tree tubing does work, but not with dirt

Using dirt tubes of height 2 and 3, normal trees still grow: enter image description here

However, using cobblestone tubes, large trees always grow: enter image description here