At the previous rate, it would take almost 27 days for half of the
short grass to convert to regular dirt with grass. And therefore
54 days in total to reach 75% conversion, 81 days for 87.5%, etc.
At the new rate, it should take about 4.5 hours for half of the
short grass to convert back to dirt wit grass.
At the previous rate, it would take almost 2 days and 15 hours of
playing time for half of the reedmace to grow. (and therefore 5 days
and 6 hours for 75% to grow, etc.)
The new rate should require 2.25 hours of playing time for half of
the reedmace to grow.