Light Block prevents the growth of many blocks

Light Block prevents the growth of

• amethyst from budding one

• sugar cane, bamboo, kelp, tree, mushroom

• big dripleaf

• grass, fern, seagrass

• glow lichen

• vines, cave vines, weeping vines, twisting vines

• chorus plant

It also prevents the growth of grass, flowers, corals by using bone meals on grass blocks/ under water in warm ocean. (It also prevents player using bone meals on these blocks.)

It doesn't prevent the growth of fungus.