Growing a 2 × 2 spruce tree in a forest biome converts the dirt under the tree to podzol. Not sure if this works as intended as it did not happen in 1.12.2.
Growing 2x2 Spruce Tree Causes Dirt/Grass underneath to turn into podzol
Spruce changes dirt to Podzol
Spawning A 4x4 spruce tree causes the grass to turn into Podzol
2x2 spruce tree transmutes dirt to podzol
Growing a 2x2 spruce tree with bonemeal turns surrounding grass into Podzol
Dirt+4 spruce sapling =PODZOL
Growing 2x2 spruce using saplings on beach resulted biome change to taiga.
Spruce 2x2 grown in grass make Podzol
Big Spruce Tree generates Dirt Podzol (from Spruce Saplings)
When you plant big spruce (2*2) around it appears a circle of podzol
Podzol when using BoneMeal on Spruce
Podzol spreads with air/solid block in between