A fitness center franchise and a dollar store chain are expanding to a Wheaton shopping plaza beset by vacant storefronts.

Planet Fitness will move into the former Office Depot space in the strip mall at Blanchard Street and Naperville Road, just north of the Town Square center. The New Hampshire-based chain of gyms is planning for a spring opening, a corporate spokeswoman said.

The nearly 20,000-square-foot club will feature cardio and strength equipment and free fitness training for all members. Memberships will start at $10 a month.

Fitness buffs who sign up for a Black Card membership that costs $21.99 a month will have access to a spa with massage chairs, tanning beds and other amenities, the spokeswoman said in an email.

Office Depot opened in 2003 after renovating the space that previously housed a Sears hardware store.

In the empty space next door, Dollar Tree will fill the void left by the closing of a Walgreens drugstore years ago. The discount retailer is expected to open in late summer at 1790 S. Blanchard St., Wheaton Economic Development Director Jim Kozik said.

A seasonal costume store -- Spirit of Halloween -- has occupied one of the storefronts in the plaza in recent years on a temporary basis.

Property tax bills on the 2-acre site were addressed last year to National Shopping Plazas Inc. in Chicago, according to DuPage County records.