What am I supposed to do here?

You are in the maze garden of your house, except the year is 1808.  
Capability is busy planting the family tree.  Don't bother him.  He has
finished planting the hedge for the garden maze.  Ten or so more years, 
and it will be quite a sight.

Isn't there a place in the maze you would rather not have a hedge?

Have you climbed the family tree in the present day?

Did you examine the maze, while in the tree?

I wonder what is in the inaccessible area?  

Now back to 1808, the folly, if you read the plaque in the present
day, was constructed on the sight where you found the statue to get you
here.  It was not constructed very well, and there is nothing you can
do to stop it from falling.  So, you better leave that bean pole in 
place, at least until you have finished you business here.

Isn't there something you found that might stop a hedge from growing?

The weed killer.  Now where to use it?

Make your way to the lower right hand corner of the fenced in area.

This is area you want to access in the present.

Now walk one square either west or north.

This is where the hedge is planted.

Squeeze the weed killer bottle.