Musk Thistle

Type: Broadleaf biennial

Size: To 6 feet tall and 18 inches wide

Where It Grows: Landscape and garden areas in full sun

Appearance: Musk thistle has prickly leaves growing off of tall stems topped by heavy 2-inch purple flowers.

Control: Mulch your garden to prevent musk thistle. Use a postemergence herbicide or dig the weed out yourself.