Is GMO indica or sativa? Its genetics, names and family tree

The two parents

Chemdawg is the hybrid that the breeder Chemdog has grown and distributed since 1991, from what Leafly says was thought to be Northern California bag seed that came via a Colorado Grateful Dead concert.²⁰ GMO’s Chem parent is the D cut: in 2001 Chemdog germinated three more of his original seeds, labeled C, D and E, and kept D.^5,6,7,10

Girl Scout Cookies (GSC) was bred by the California breeder Jigga from a sub-type of OG Kush and an intermediate strain called F1 Durban.¹¹ The cut in GMO is the Forum cut: Leafly’s genealogy says a grower known as Ghost obtained a Cookies cutting in 2008, and it took its name from the internet forums where growers debated it.^5,6,12,21

Chem D × GSC, D-Cookies or Chem Cookies?

The original seed line goes by three names. Leafly’s 2022 feature says the packs went out as "Chem D x GSC", High Times wrote in 2017 that the keeper came from a pack of Mamiko Seeds’ D-Cookies, and Weedmaps calls the line Mamiko’s Chem Cookies.^5,8,24 SeedFinder lists Chem Cookies, Garlic Cookies and GMO as other names for Mamiko’s GMO Cookies, and Leafly’s 2024 feature says the strain was later sold as Chem Cookies.^6,9

How indica is it?

Every source that gives a split puts GMO far on the indica side. AllBud lists 90% indica / 10% sativa, as do Barney’s Farm’s GMO, GMO Cookies and Garlic Cookies seeds and Zamnesia’s GMO Cookies; Barney’s Farm’s autoflower, crossed with its Super Auto #1, is 80/20.^{1,2,3,26,27,28} Leafly files it as an indica-dominant hybrid with mostly calming effects; Weedmaps and SeedFinder call it a hybrid.^4,5,6 Weedmaps describes a surprisingly bright, uplifted opening before a sleepier finish (see effects).⁵

Is it genetically modified?

No. The breeder’s note on SeedFinder’s entry for Mamiko Seeds’ version says GMO Cookies is not a genetically modified organism but a cross between Chemdawg D and a GSC Forum cut.⁶ Leafly’s 2022 feature says Skunkmasterflex named it after a news item about transgenic dessert, and because the plant grew so strangely that it looked as if scientists had modified it (see history for the other explanations of the name).⁸

Clones, seeds and look-alike names

The famous GMO is a selected plant that travels as cuttings: Leafly’s 2022 feature says most state markets sell GMO clones, and Prime Cuts Nursery lists it in its strain library, though not on its current menu. Weedmaps’ strain page says neither seeds nor clones of GMO Cookies appear to be available online.^5,8,21

Seeds sold under the names are separate versions. SeedFinder lists four breeders’ GMO Cookies (Mamiko Seeds, Plantation Premium Seeds, Skunk House Genetics and Zamnesia) and five versions of GMO, one of them Barney’s Farm’s.^29,30 Barney’s Farm sells GMO, GMO Cookies and Garlic Cookies as separate feminized lines, all listed as Chemdawg × Girl Scout Cookies, though GMO is given 75–80 days of flowering and the other two 63–70, plus a GMO Auto; Dr. Blaze sells seeds under the name GMO, described as an S1 of Chemdog × Girl Scout Cookie.^{2,26,27,28,31} Sour Garlic Cookies, from Bloom Seed Co, is listed by Leafly as a separate strain with the same two parents.³²

What our lab data adds

On state lab certificates the names split: of our 2,159 tests, 1,246 are labeled plain GMO, 750 use Garlic Cookies (some as "GMO (Garlic Cookies)") and 163 say GMO Cookies. By state, most results from Michigan, Nevada and Washington say plain GMO, while most Maryland results say Garlic Cookies (543 of 617).³³

Our strict matching excluded a further 1,899 results (1,281 of them flower) whose names add another strain or a cross, led by "GMO x Skywalker OG" (238 results), then "GMO x Root Beer Bulk" (48), "Legendary GMO" (39) and "GMO Zkittlez" (35).³³ GMO is a prolific parent: Leafly’s 2022 feature counted more than 155 GMO crosses reported on SeedFinder, over five generations.⁸