Hi @kyle - welcome to the farmOS community!
Someone asked about similar ideas in this topic - see my answer there for some general ideas and ways of thinking: How to easily map individual trees?
This might also be relevant: Hierarchical function - watering "fruit-trees" (group of trees) instead of each single tree
If you need to be able to record logs against individual trees, then you will probably need an asset per tree (a lot I know!). Otherwise, you might just want to have an asset per variety (further broken down by row perhaps). Ultimately the way to think about it is in terms of “management units” - so the granularity that you decide on is a balance between the need for granularity vs the data management burden.
What level will you be logging at, most often? The block level? The variety level? The row level? the individual tree level?