saplings - no
plants - yes, they attack em if they are a valid target

had a test running where i planted carrot seed plants around my house - let them fully grow - and only got the one near my front door destroyed (where the enemys are approaching from) the rest is still intact (for 80 days now)

still there in the open
https://steamcommunity.com/sharedfiles/filedetails/?id=2647923987
planted them on soil - let them fully grow - placed grass over the soil