The following blocks are new blocks added in 1.21.5 that may naturally generate next to a tree, and therefore need to be added to the default configuration: (trees/default.yml)
- minecraft:bush
- minecraft:cactus_flower
- minecraft:firefly_bush
- minecraft:leaf_litter
- minecraft:short_dry_grass
- minecraft:tall_dry_grass
- minecraft:wildflowers
The following blocks are new blocks added in 1.21.5 that may naturally generate next to a tree, and therefore need to be added to the default configuration: (trees/default.yml)