Artist Mariah Anne Johnson creates landscape-like installations of folded bedsheets. The artist's work (seen above in this detail of a previous installation) will be featured in October at Harmon Art Lab, one of of several new spaces hosting art openings this month. (Harmon Art Lab)

This fall’s theme isn’t Andy Warhol, but good guess. A pair of Warhol-themed shows just opened at the National Gallery of Art and the Hirshhorn Museum and Sculpture Garden. There’s also a bunch of related Warhol programming coming up, including a Nov. 12 concert in the auditorium by the husband-and-wide duo of Dean Wareham (of Luna fame) and Britta Phillips , set against a backdrop of the late artist’s silent screen tests.

But there is another, clearly identifiable trend this October. That’s the appearance of several new galleries. A bunch of them seem to have sprung up, seemingly overnight, like mushrooms.

On Oct. 5, the Adam Lister Gallery opens “From Over Here,” its first exhibition in its brand new space in Fairfax. Lister is in the same building as before, but it’s now on the lower level and the entrance is on University Drive between the loading dock and the Fairfax Art League Gallery. The new show features work by Diana Adams, Remmi Brant and others.

On Oct. 8, Harmon Art Lab opens its second show ever, featuring the work of painter Michel Modell and Mariah Anne Johnson, a fascinating installation artist who makes landscape-like work using carefully folded bed linens. The best time to go is the opening or the artist talk on Oct. 15 from 2 to 3 p.m.

In Bethesda, the old Fraser Gallery space is now known as Gallery B , which will be operated as a rental gallery by the Bethesda Arts and Entertainment District and the Bethesda Urban Partnership. It opens its first show on Oct. 14, with figurative bas-relief bronzes by local architect and artist Mark Kramer.

On Oct. 15, two new galleries — and one newish one — host openings. In Hyattsville, it’s A\Work Gallery’s show Intellectual Property,” featuring the work of Courtney Miller Bellairs. (The gallery shares space with the architecture and interior design practice of MS&R Architects. Bellairs is also an archietct.) Over on Capitol Hill, Vitruvian Gallery is launching with a singular focus: the male figure. Longtime Washington painter Rob Vander Zee will have the first exhibition there. And the Adah Rose Gallery, which opened in Kensington last month, hosts a reception for its second show. Called “A Glimpse and a Witness to Time,” it features work by two of the area’s rising art stars, Mei Mei Chang and Joan Belmar.

Finally, October also sees the return of an art-world staple: the late night afterparty. On Oct. 14, the Hirshhorn Museum and Sculpture Garden hosts its popular Hirshhorn After Hours event from 8 p.m. to midnight. A week later on Oct. 21, it’s the Corcoran Gallery of Art’s turn with “NOW at Night.” It’s an expensive shindig, but the $150 ticket goes to support the museum’s contemporary exhibition programming. You also get one last chance to see “Chris Martin: Painting Big,” which closes at the Corcoran Oct. 23, as well as the museum’s hot new fall show, “30 Americans.”