How to spread grass for animal pen

[Thatguyintheback100]

Does planted grass spread to tilled farmland or "stomped to dirt" ground, I've had two squares of grass turf surrounded by farm land for about a real life day and nothing has happened. Does it spread at all?

[MagicManICT]

It takes time--days, even weeks. also depends on how many tiles you have plowed up. If you have a lot, you'll see tiles swap earlier as it's a probabilistic outcome.

[meus]

The fastest and most reliable method is to collect crop seeds (harvest or dry WWWs for a few hours) and manually plant the grass. Waiting for the decay mechanic to kick in can literally take forever. You're better off just planting it.

Another reason why you might not be seeing the desired effect is if the animals are already starved (no food in a trough) and might already be consuming the grass you've been trying to spread, creating dirt tiles in its place.