Foliage can come in six different grades, or tiers.
- Grade 0 foliage represents small grasses and very tiny plants. Anything can destroy or consume this foliage, and it often grants very little food.
- Grade 1 foliage represents most small, leafy plants. It is consumable or destroyable by mostly anything.
- Grade 2 foliage is often classified as small bushes or somewhat medium-sized, leafy plants.
- Grade 3 foliage represents mid-sized, woody bushes and occasionally very small, young, woody trees. This foliage typically respawns in 30 minutes. It feeds mid-sized herbivores such as Parasaurolophus, Saichania, and large Pachycephalosaurus.
- Grade 4 foliage is often represented by large, woody bushes and smaller trees. Some extremely large, leafy plants are also grade 4 foliage. This type of foliage is quite large, and often feeds the Parasaurolophus well. Nothing smaller can destroy or consume this foliage. It often has respawn timers anywhere from 30 to 45 minutes. Usually this foliage will collapse into the ground when consumed.
- Grade 5 foliage will be most large, woody trees. These are only edible or destructible by the Apatosaurus; or, under unusual conditions, very large members of other species. It typically respawns in 60 minutes. Some large, woody plants will fall when consumed. Others will lose their leaves, leaving behind a woody, leafless tree until respawn.
- Grade 6 foliage is indestructible. Extremely large trees that may lie as the focal points of certain areas may be foliage grade 6.
A creature's size often correlates with what kind of foliage it is capable of both consuming and trampling.
The only exceptions to the foliage grade system are hatchlings, which can eat any foliage picked up in a bundle and dropped by a parent. This is to prevent starvation in incredibly young offspring.
Some types of foliage are exclusive to certain creatures. Currently, the only type of foliage exclusive to one creature is the Lurdusaurus. The semiaquatic Lurdusaurus can only eat kelp found in large bodies of water, such as the ocean or lakes. Without proper mitigation against it, the Lurdusaurus will gain a large amount of food poisoning from eating terrestrial plants. Kelp is mostly inaccessible to terrestrial herbivores due to the depth underwater which it is found at.