GMO

Also known as: Garlic Cookies, GMO Cookies, Chem Cookies, Garlic Mushroom Onion

Breeder: Original cross by Mamiko Seeds (Spain, ~2012) as Chem Cookies. Phenotype selected and named by Skunkmasterflex (Skunk House Genetics, USA) in 2013.

Lineage & Genetics

Cross: Chemdawg D (Chem D) x Girl Scout Cookies (Forum Cut)

Chemdawg D (Chem D) — legendary balanced hybrid from seeds obtained at a Grateful Dead concert around 1991. Known for sharp diesel-fuel chemical-solvent aroma, high potency often exceeding 25% THC, uplifting creative cerebral effects with strong body buzz. Parent or ancestor of both OG Kush and Sour Diesel. In GMO, Chem D contributes the piercing petrochemical-garlic pungency, raw potency, and the savory/sulfurous VSC chemistry. Girl Scout Cookies Forum Cut — Durban Poison x OG Kush, the highly prized Forum phenotype. Known for dense trichome-coated bud structure with high calyx-to-leaf ratio, sweet minty-earthy cookie-dough aroma, and intense euphoria followed by deep full-body relaxation. In GMO, the Forum Cut contributes dense bud structure, heavy resin production, high THC ceiling, and calming indica-dominant effect profile. The typical Cookies sweetness is almost entirely overtaken by Chem D's savory funk.

Terpene Profile

Aroma: Fresh garlic cloves blended with diesel fuel — an immediate room-filling hit of savory funk. Undertones of onion, damp earth, and skunk. The smell is invasive: a single nug can perfume an entire room. Grinding intensifies to piercing fuel stink and garlic-onion sharpness that can sting the nostrils. Black pepper and damp earth become more pronounced. The odor clings to fabric, skin, and hair.

Flavor: Inhale is deeply savory — described as combusting garlic bread dipped in diesel. Garlic and fuel lead with rich earthiness of wet soil and forest floor. No fruit or sweetness. Some phenotypes have a rubbery chemical edge from Chem D lineage. Exhale evolves into spicy woody finish with lingering funky aftertaste of mushroom soup, coffee grounds, and skunk. A savory umami coating on the palate persists for minutes. Well-cured GMO produces smooth thick smoke with heavy mouthfeel.

Effects & Experience

Onset: Fast-rising cerebral buzz with uplifted mood in the first 0-15 minutes. Brief window of clear-headed happiness, gentle giggles, and a spark of creative thinking. CREEPING POTENCY WARNING: the high builds slowly over 15-20 minutes before hitting full force — many users accidentally overconsume because the initial effects feel manageable.

The indica dominance takes over at 15-60 minutes with deep spreading body stone. Muscles unwind, limbs grow heavy, couch-lock becomes near-inevitable. Mental activity smooths and racing thoughts slow to tranquil drift. Users report feeling glued to the seat in profound physical relaxation. The sedative effects persist for an unusually long time, often easing into drowsiness or outright sleep. Strong appetite stimulation.

Duration: 2-4 hours from flower; edibles extend to 4-8 hours

Growing Characteristics

Grow Tips: CARBON FILTRATION IS NON-NEGOTIABLE — GMO is one of the loudest strains ever bred rated 99/100 on the Abstrax Loud Factor scale. The garlic-skunk-diesel smell becomes pronounced by mid-flower (week 6) and intensifies relentlessly through harvest, drying, and trimming, permeating walls, ductwork, clothing, and adjacent rooms. Minimum: high-quality activated carbon filter matched to inline fan CFM (6-inch minimum for 4x4 tent, 8-inch for larger), inline exhaust running 24/7 (never turn off even at night), sealed ductwork with all seams taped, negative pressure in grow space so tent walls bow slightly inward. If single filter insufficient (common with GMO): add second standalone carbon filter + fan in lung room, ONA gel OUTSIDE grow room only (never inside as it alters terpene profile), or double-filter ducting carbon filter inside tent to second carbon filter outside. Continue filtration during entire drying period — drying produces equally intense odor spike. Outdoor: no practical way to contain smell, plant far from neighbors with natural windbreaks, not suitable for stealth grows. STRETCH during flower transition is SIGNIFICANT — plants routinely double in height sometimes more during first 2-3 weeks of 12/12. If you flip at 18 inches expect 36-40+ inches at end of stretch. Shorten veg or train aggressively. TRAINING (essential not optional): Top once or twice at 4th-5th node around week 3 of veg — tolerates aggressive topping well. LST after topping bending and tying branches for flat even canopy. SCROG highly recommended — evenly spaced bud sites fill a screen nicely. Supercropping during early-flower stretch if tops shoot too high — stems are flexible enough to recover. Support in late flower by week 7-8 when buds become extremely dense and heavy — trellis net or stakes essential, branches will sag or snap without support especially during the last swell. DEFOLIATION: Light in late veg removing large fan leaves, more aggressive around week 3 of flower (the most impactful timing), remove selectively not wholesale focusing on leaves receiving no light, blocking bud sites, or creating humidity pockets. NUTRIENTS: Heavy feeder tolerating strong nutrient levels without easily burning. Standard high-nitrogen veg formula, vigorous growth handles heavier feeding than many strains. Switch to high-P high-K bloom formula at flip. Bloom boosters/high-PK supplements weeks 3-7 maximize bud size. Maintain steady Cal-Mag especially under LED. Reduce nitrogen sharply after stretch completes — excess N in mid-to-late flower causes excess foliage, muted aroma, and delayed ripening. Organic cultivation (living soil, compost teas, organic top-dressings) reported to produce most flavorful buds — slow-release nutrients may encourage terpene production. Mycorrhizal inoculants boost root health. Flush with plain pH-balanced water final 7-14 days for cleaner burn and sharper garlic-fuel flavor. PEST AND DISEASE: Above-average resilience with multiple growers reporting PM resistance even when other strains succumbed. But extreme bud density means it is NOT immune to bud rot — airflow management essential. Late-flower hermaphroditism not commonly reported but any stress during extended 10-11 week flowering could trigger nanners — keep environment stable. DO NOT HARVEST EARLY — the single most common mistake. Growers who harvest at week 8-9 consistently report buds lacked weight, density, and aroma intensity. Target harvest week 10-11 (70-77 days of 12/12). The final 7-14 days is where GMO really puts on weight — buds stack density and resin dramatically, sugar leaves get coated in trichomes, aroma reaches peak intensity. Trichome targets: mostly cloudy/milky with 10-15% amber for peak balanced effect, higher amber 20-30% for more sedative/CBN-forward medical/sleep use. Check calyxes not sugar leaves. The grow room smelling intensely of garlic like a pantry indicates peak terpene load. DRYING: The 60/60 Rule — dark room at approximately 60F and 60% RH for slowest most even dry preserving volatile terpenes. Hang whole plant or large branches (leaving stems and fan leaves attached slows dry and protects trichomes). 10-14 days minimum — drying in less than 7 days will flash off volatile compounds producing muted hay-like smell instead of garlic-diesel funk. Total darkness (UV degrades terpenes). Gentle air circulation never pointed directly at hanging plants (causes case hardening where outside dries while moisture trapped inside). Continue carbon filtration during entire dry. CURING: Airtight glass mason jars filled 75-80%, target 58-62% RH with small hygrometer in each jar. Burp weeks 1-2 daily 5-15 min, weeks 3-4 every 2-3 days, week 5+ weekly. If humidity reads above 65% in jar leave lids off several hours — mold risk. Below 55% buds are over-dried. Extended cure strongly recommended: flavor noticeably improves at 4-6 week mark with garlic-onion edge becoming more nuanced and coffee-spice notes emerging. Connoisseurs report optimal at 45+ days. Properly cured and stored retains aroma and potency 6+ months. Extraction notes: premier hash strain with prolific trichome production translating to high extract yields. High wash yields for ice-water hash with large easy-to-separate trichome heads. Excellent rosin press yields (>5% reported commercially). Scissor hash from trimming is notably sticky and potent.

History & Origin

Mamiko Seeds created the Chem Cookies line around 2012-2013 by crossing Chemdawg D with GSC Forum Cut. In 2013 Skunkmasterflex acquired seeds and pheno-hunted an exceptional plant with unusually pungent savory-funky aroma, naming it GMO — not as a garlic acronym but because of GMO-ingredient headlines about Girl Scout Cookies and because it grew like it was genetically modified. The clone spread through underground networks primarily in California during 2014-2017 building a cult following among connoisseurs and hash makers. In December 2017 Danny Danko featured it in High Times. Dispensaries began relabeling it Garlic Cookies to avoid GMO confusion, and the Garlic Mushroom Onion folk etymology took hold. GMO became one of the most sought-after breeding parents of the late 2010s and 2020s. In 2021 and 2023 Abstrax Tech published research in ACS Omega identifying the specific chemical compounds behind the aroma — prenylated volatile sulfur compounds and skatole/indole — providing the first scientific explanation for why this strain smells like garlic.

Notable Crosses

Strains bred using GMO as a parent: