A landscape edging form assembly for forming a concrete edging in place, includes first and second sidewalls and a series of flexible connectors extending between and interconnecting the sidewalls. The flexible connectors are spaced apart from each other in the direction of the length of the landscape edging form and enable the landscape edging form to be extended from a non-erected width where the flexible connectors are in a slack condition to an erected width where the flexible connectors are in a taut condition. Preferably, the sidewalls and the interconnecting flexible connectors of the landscape edging form assembly are a prefabricated component of the assembly. Another form assembly includes bendable sidewalls, spacers, and positioning brackets and is used to form a sinuous concrete landscape edging in place.