jQuery: enabling/disabling datepicker

$("#from").datepicker('disable'); should work, but you can also try this:

$( "#from" ).datepicker( "option", "disabled", true );

Also set the field to disabled when you disable the datePicker e.g

$("input").prop('disabled', true);

To stop the image being clickable you could unbind the click event on that

$('img#<id or class ref>').unbind('click');