Join Date: May 2009
Location: Winnipeg, Manitoba, Canada
You absolutely have to rotate. Five acres is plenty for 3 horses if the grass is lush in summer, but the average lawn in various other parts of the world will be overgrazed fairly quickly. Your winters can probably compare to our autumns when things start dying. Regardless if you don't get winter, everything slows down and rests a bit. The temps and weather patterns change, and the grass wants to "sleep" so to speak.
I would build a minimum of two separate enclosures (three if you can) with easy gates so you can keep them open in summer. In winter, keep them to one area, and supplement with hay. Let the other areas grow and then rotate.
Keep in mind, due to the change in climate for winter months, the grass is nowhere NEAR as nutritious as it is in summer. You may think they can graze all winter because you don't get snow but you simply can't. You may be able to get away with using less hay then we do in snowy climates, but not as much as you think.
I hope God tells her to smash her computer with a sledgehammer.