The adjustable guard assembly is connected to a head assembly of a string trimmer. The adjustable guard assembly includes a housing. The housing includes a mounting portion, which connects to a motor case. The housing further includes a deck portion, which extends from the mounting portion. The deck portion has a proximal end and a distal end. A first skirt member extends along and downward from the distal end of the deck portion in a generally radially outward direction. A first blade assembly includes a first blade member, provided in the interior of the first skirt member, to engage a rotating string member.