Someone

alias seedtimer {
  timerseedtimer 1 5400 echo 5 -a * It has now been 90 minutes since you planted your herbs. You should check and see if they're done.
  timerseedtimerbeep 1 5400 beep 1
  timerseedcheck 9 600 seedcheck
}

alias seedcheck {
  if ($duration($timer(seedtimer).secs,1) == $null) {
    //echo 5 -a * Your seeds are Done.
  }
  else {
    //echo 5 -a * Your seeds currently have:
    //echo 5 -a * $duration($timer(seedtimer).secs,1) left.
  }
}