The wither timer isnt quite random. ff14gardening lists the timers for each seed, basicly its 24 hours to get to "seen better days"/purple stage and another 24 hours before it dies. Some seem to have twice that time before they die
I dont mind tending but tending 12-13 plots twice a day does get tedious i agree.
so tend_plot does seem like a lifesave, even fertelize plot i would use
