If I want to fill a field the size of a small park with grass, it requires the sacrifice of 10,000 trees. This doesn't make a lot of sense and becomes rather tedious after the 10th time planting and deconstructing a forest worth of trees.

I wound up altering the composting recipes for 10x the artificial grass output.

Hey, I made it a little expensive due to it's landfill capability. (100 wood vs 50 Stone felt realistic)
The idea behind the high cost for Zen Garden was that there is no hassle with fertilizer / nutrient / seed, you just get infinite wood for time/water.

It is easy to nerf the cost, but I would need a little more feedback since it is a scaling and timeframe solution. Which depends on playstyle.
In my test-run (see attached pic 4.) I solve the issue with speed beacon and speed module. Which as a bonus increases the pollution drain, which can be an overpowered mechanic.

I have not touched the code for a while since I was playtesting, but I would like to hear some other feedback (even the rest of the features), I will take them into consideration, maybe introduce a startup slider setting or cost multiplier.

Hey Almost forgot, I also put in a breeding recipe, so once Gleba is unlocked you can make 10x Grass form 5 Grass + 5 Landfill +50 Nutrient.

I was not even aware that grass could be used as a landfill. But regardless, I think most people would be using it to make brown terrain look green. People who download this mod are interested in the beautification of their base, after all.

I don't think wood and stone are comparable at all. You can automatically mine tens of thousands of stone with zero effort. Acquiring wood in the early-to-mid-game requires destroying the natural environment, or planting then harvesting thousands upon thousands of trees manually. All to make a little patch of the ground turn green.. Even after the 10x output modification I made, I only managed to cover about 1 screen of grass before leaving Nauvis.

I would probably cut the cost 10x, while also boosting the output 10x, to make it feasible to scale up. Add some landfill to the recipe if you are concerned about it acting as a landfill substitute.10 wood, 5 landfill and 1000 water for 10 compost. Very expensive in terms of stone, but possible to scale up with effort. And it acts as landfill with half the stone cost in exchange for your effort.

What exactly is the purpose of grass if it's impossibly expensive to use cosmetically until late game?

I have no other complaints so far. This is just about planting grass in the early to mid game.

Yeah, you are right for the early game, even making your first Zen Garden is quite expensive, but after that was done, it scaled nicely with time, I built whole Island as well from just Grass.

The mod also aims to have pollution control, since it is a copy of the Base Grass-1 it has the highest pollution consumption among tiles as well as acts like decorative and makes it possible to plant any Nauvis tree.

I have the breeding recipe, but have not even tried to use it so far, I will probably nerf the costs to half, 50 wood or 100 spoilage. Productivity is also allowed for the compost.

You are also right about planting manually and harvesting before you have access to the Agricultural tower or first Zen-garden. For this I had a Nauvis only early agricultural tower in plans. Probably will add it as well if I get to actually updating the mod.
Your comments and feedback give me motivation to work on it so I am grateful.

Meanwhile I am adding another Screenshot, where I am negating 56 Legendary biolabs, 200 pollution/ minute with the Gardens