G13 Strain

G13 Strain: The Indica With the Best Cover Story in Cannabis

The G13 strain is an old-school, heavily indica Afghan-type plant that's earthy, piney and skunky, hits with a quick euphoric lift and then pins you to the couch. What made it famous, though, isn't the high — it's the story. For decades G13 has been sold as a "government" strain, supposedly bred by U.S. agencies at the University of Mississippi and smuggled out as a single cutting. A line in the 1999 film American Beauty sealed the myth for a whole generation. For heavy, evening-lane flower right now, start with our THCA flower collection.

Here's the honest version. Nobody has ever documented who bred G13, and the one federal cannabis grow that did exist was famous for low-potency weed — not elite indica. The plant itself is real, though, and it's left a long family tree, from Sensi Seeds' Mr. Nice to Barney's Farm's Tangerine Dream. Below: what the legend says, what the evidence says, how the high unfolds, what the potency numbers mean, how to grow it, and how to judge a bag sold under the name.

G13 Strain Genetics & Lineage

• Type: Indica. Leafly and Weedmaps both list it as an indica; AllBud calls it an indica-dominant hybrid at roughly 70% indica / 30% sativa, and The Cannigma also says indica-dominant hybrid.
• Breeder: none on record. SeedFinder files G-13 under "unknown or legendary" genetics with its lineage simply marked as indica.
• Ancestry: Weedmaps lists Afghani as both parents and says the exact parentage is unknown. AllBud says the parentage is unknown and mentions experiments with Afghani strains. Sensi Seeds describes G13 as a premium Afghani plant.
• THC: Leafly lists 20% with 1% CBG; AllBud 22–24%; Weedmaps 18–24%.
• CBD: negligible — The Cannigma lists 0.1%.
• Aliases: G-13, G Thirteen, "Government Indica Strain 13" (Weedmaps) or "Government Indica Strain 1" (AllBud's spelling).

The legend: a cutting from "growing chamber #13"

The story goes like this. In the late 1960s or 1970s, U.S. government agencies collected the best cannabis from around the world, bred it at a secure facility at the University of Mississippi, and produced a super-strain. A technician slipped out a cutting, and it found its way to the Netherlands. The Cannigma says the cutting reportedly reached Dutch breeder Nevil Schoenmakers; a contributor on Erowid recalls Howard Marks saying in the film Mr. Nice that it came from a government employee who stole a plant from "growing chamber #13," which then reached Sensi Seeds.

It's a great story. It's also unsourced at every step — no name for the technician, no date, no paper trail.

What the evidence actually says

Erowid looked into it and found that the only U.S. government cannabis it knew of came from the National Institute on Drug Abuse, which contracts with the University of Mississippi to grow research cannabis — including for the Compassionate Use Program that ran from 1975 to 1992. That cannabis was "notoriously low in THC," roughly 2–5%, and Erowid found no published literature showing higher-grade plants ever came out of the program. Its editor's verdict: it "seems highly unlikely" G13 is anything but a Hollywood product.

Leafly calls the origin story an urban legend that is "probably not true," and Weedmaps says there's "no reliable evidence that federal agents actually bred G13." The more boring — and more likely — explanation is that G13 is a strong Afghan-type selection that picked up a great name. JointCommerce floats a West Coast selection from Afghan landrace stock in the late '70s or early '80s, but cites nothing for it, so treat that as a guess too.

The lineage myth: Afgoo and Maui Haze

One dispensary blog says G13 comes from crossing Afghani with Maui Haze to make Afgoo. No database we checked supports that — Weedmaps, AllBud and SeedFinder all treat the parentage as unknown, and an Afghani × Maui Haze cross would be expected to pull more sativa than G13's heavy indica profile shows. We'd ignore it.

G13's offspring

Whatever its origin, G13 became a serious breeding parent:

• Mr. Nice (G13 × Hash Plant) — Sensi Seeds released it in 1999 and named it after smuggler-turned-author Howard Marks.
• Tangerine Dream — Leafly describes Barney's Farm's cross as G13, Afghani and Neville's A5 Haze.
• G13 Haze, Amnesia G13, HP-13 and Lemon G13 — names that show up across Weedmaps, The Cannigma and JointCommerce as relatives and substitutes, from various breeders.
• Valley Ghash and Tangerine G13 — listed by The Cannigma as direct descendants.

G13 Terpene Profile

Leafly lists myrcene as G13's dominant terpene, with limonene and caryophyllene behind it. The Cannigma's compiled lab data reads differently: linalool 0.48%, caryophyllene 0.43%, humulene 0.33% and pinene 0.28%. A third set from AskGrowers, cited by Collective Cannabis, leads with ocimene, humulene and carene at about 1% total terpenes. That spread is what you'd expect from a strain sold by many growers under one name. Caryophyllene is the one with real research interest: a 2008 PNAS study identified beta-caryophyllene as a "dietary cannabinoid" that binds CB2 receptors.

• Myrcene: The earthy, herbal base, and the terpene most often associated with the classic indica couch-lock — though that link is folk wisdom more than proven science.
• Caryophyllene: The pepper and wood under the pine. It shows up on both Leafly's and The Cannigma's lists, so it's the most consistent part of the profile.
• Linalool: Floral and soft. The Cannigma ranks it first by percentage, which fits G13's reputation as a mellow, unwinding strain.
• Humulene and pinene: The woody, hoppy and fresh-pine notes that match the flavor tags — "pine, woody" on Leafly, AllBud and Weedmaps alike.

The skunky, pungent edge most reviewers mention doesn't come from any of these. It comes from trace sulfur compounds that labs rarely report — which is why two jars with the same terpene list can smell very different.

Appearance

AllBud describes dense, lumpy, dark olive-green nugs with amber hairs and a heavy coat of light-blue trichomes. Weedmaps calls the plants compact and resin-heavy with dense flowers. That's the classic Afghan look — tight, chunky buds rather than long fluffy spears — and the resin is part of why G13 became a favorite hash and breeding parent.

Aroma and Flavor

Open a jar of real G13 and you get pungent earth and skunk first, then pine and wood. AllBud's aroma tags read berry, earthy, pungent, skunky and sweet, and it warns the skunky-berry smell "can quickly become harsh." On the inhale, AllBud's tasters get sweet and earthy, with a skunky exhale that's "surprisingly pleasant."

The flavor tags line up across the big databases: Leafly lists earthy, pine and woody; AllBud pine, sweet and woody; Weedmaps' reviewers report woody (38%), earthy (33%) and, a little surprisingly, orange (29%). One Leafly reviewer says their batch had "a nice gassy / diesel truck motor smell," and another calls the whole experience "very old school." The Cannigma sums it up as skunky scent, sweet pine flavor.

Recreational Effects

G13 is a body strain with a short, happy front end. On Weedmaps, users report:

• Relaxed (48%): the headline effect, and the one almost every review mentions.
• Sleepy (26%): Leafly lists sleepy first among its top effects.
• Euphoric (26%): AllBud describes a "euphoric lift" with a brief boost of energy and motivation at the start.
• Happy: one of AllBud's four effect tags, alongside euphoria, relaxing and sleepy.
• Heavy: AllBud says the lift turns into a "heavy buzzy effect that will lull you down into a deep sense of laziness and relaxation." A Leafly reviewer put it more simply: "it unglued me from the bench."

How the high unfolds: onset, peak and duration

• First few minutes: a euphoric mood lift and a little burst of energy.
• 15–45 minutes: the shift — the energy fades and a heavy, buzzy body relaxation takes over.
• 1–3 hours: deep laziness and sleepiness. This is where G13 earns its bedtime reputation.

Leafly's reviewers keep repeating one warning: "Not a beginner's flower," and "it can get overwhelming if you're a new smoker." Plan on staying in.

→ Experience it yourself — shop Diesel Hemp's THCA Flower

How Strong Is G13?

G13's reputation is bigger than its numbers. The published figures:

• Leafly: 20% THC, "higher THC than average," plus 1% CBG.
• AllBud: 22–24% THC.
• Weedmaps: 18–24% THC.
• The Cannigma: an average of 16.2% across the lab results it compiled, with a range from 10% to 29%.
• AskGrowers (via Collective Cannabis): 20–21.75% THC, with small amounts of CBG, CBC and THCV.

The Cannigma also cites Michael Backes' Cannabis Pharmacy for a 1970s-era claim of more than 29% THC — we couldn't check that figure, and it would have been extraordinary for the time. JointCommerce's 18–25% range has no named source. Realistically, a good G13 cut today lands in the high teens to low 20s. Its "strong" reputation comes from how heavy the high feels, not from record-breaking lab numbers.

THCA flower is labeled differently from dispensary flower: the lab reports THCA, which converts to THC when heated, plus a small amount of delta-9 THC. When you compare a batch of G13 against the 16–24% range above, compare total THC on the COA, not the headline number — our guide on how to read a THCA flower COA walks through the math.

The American Beauty Effect: How a Movie Made G13 Famous

Most people first heard of G13 from the 1999 film American Beauty, where a teenage dealer sells it as a strain genetically engineered by the U.S. government — potent, but a mellow high with no paranoia. MEL Magazine credits the film with popularizing G13 as "the strain that gives you zero paranoia." The name stuck: The Cannigma notes a SweetWater brewery IPA called G13, and dispensaries still sell the strain mostly on the strength of the story.

The "no paranoia" part is movie dialogue, not data. Leafly lists dizziness among G13's negatives, and one Leafly reviewer reported a panic attack after four pulls — while another said it eased their anxiety. Like any strong indica, it depends on you and your dose.

Is the G13 You're Buying Actually G13?

Here's the uncomfortable part. With no documented breeder and no reference lab profile, "G13" on a menu can mean a lot of things — a long-kept clone, a seed line from one of several seed companies, or just a generic indica with a famous name. The terpene data shows it: Leafly, The Cannigma and AskGrowers each report a different leading terpene. Collective Cannabis also notes you'll now find 70/30 versions rather than pure indica, "so the label matters." If you want the classic experience, look for a grower who can tell you where their cut came from — and judge the bag on smell and effect, not the name.

G13 vs Similar Strains

• vs Afghan Kush and Black Afghan: the closest relatives in spirit. Weedmaps lists Afghan Kush as a similar strain, and all three share the earthy, hashy Afghan backbone. G13 tends to show more pine and skunk.
• vs Hindu Kush: another Weedmaps "similar strain" and a pure landrace indica. Hindu Kush is sweeter and more sandalwood; G13 is skunkier.
• vs Northern Lights: the other Dutch-era indica legend. Both are heavy and sleepy; Northern Lights is softer and sweeter on the nose.
• vs Tangerine Dream: G13's best-known child. Barney's Farm added Neville's A5 Haze, so Tangerine Dream is citrusy and far more upbeat.
• vs Skywalker OG: The Cannigma names it as a similar strain. Skywalker OG brings more OG fuel and spice to the same heavy body.
• vs Mule Fuel: our featured in-stock pick, and honestly not a twin. Both are heavy, earthy, indica-leaning and made for the evening, but Mule Fuel is a modern GMO Cookies × Lurch hybrid with much louder gas where G13 runs pine, wood and skunk. Want a concentrate instead? Our HBIC live rosin is on the shelf.

Who G13 Is (and Isn't) For

Good fit: experienced smokers who want an old-school, heavy indica; nighttime use; unwinding after a long day; fans of earthy, piney, skunky flavor; and anyone curious to try a piece of cannabis folklore.

Poor fit: beginners — Leafly's reviewers say it plainly — anyone who needs to be productive afterward, and people who want bright, fruity flavor. For a heavy, evening-lane flower on our shelf, Mule Fuel is the pick, from $59.

How to Use G13 THCA Flower — and How Much

THCA has to be heated to do anything. Raw, it isn't intoxicating; heat converts it to THC (decarboxylation), which is why the method matters as much as the strain.

• Smoking (joint, pipe, bong): the fastest onset. Take one or two small hits, then wait 10–15 minutes before deciding on more.
• Dry-herb vaporizer: a smoother way to taste the pine and wood than a joint, given AllBud's note that the smoke can turn harsh. Lower temperatures, around 350–380°F, keep it lighter; 390–410°F pulls the full heavy, sleepy effect.
• Pre-rolls: the no-prep option — see our THCA pre-rolls.
• Homemade edibles: decarb the flower first. Edibles take 30–120 minutes to kick in and last far longer, so start low and wait the full two hours.

How much? New or occasional users: one small puff, then wait 15–30 minutes — this is not a beginner's strain. Regular users usually find two or three hits gives the full arc from lift to couch. Use it in the evening. You can always add more; you can't take it back.

Medicinal Benefits

These are uses consumers report on Leafly and AllBud, not established clinical outcomes. Individual response varies with dose, tolerance and chemotype.

• Stress: the top-cited reason on Leafly, at 39% of reviewers.
• Pain: about 31% of Leafly reviewers; AllBud also lists arthritis, headaches and migraines. The Cannigma notes it's popular with migraine patients, citing Cannabis Pharmacy.
• Anxiety: about 31% of Leafly reviewers — though dizziness and at least one panic attack show up in reviews too, so dose matters.
• Insomnia: AllBud lists it, and it fits the sleepy, heavy finish.
• Low mood and PTSD: both on AllBud's "may relieve" list, along with glaucoma — the last one tied, again, to the legend more than to evidence.

For a plain-language primer on how terpenes are thought to shape these effects, see Project CBD on terpenes. Nothing here is medical advice, and nothing on this page is intended to diagnose, treat, cure or prevent any disease. If you take prescription medication or have a health condition, talk to your doctor before using any cannabis product.

Side Effects and Cautions

• Dry mouth and dry eyes — the most common complaints on Leafly.
• Dizziness — Leafly's third-listed negative, more likely at high doses.
• Anxiety or paranoia — despite the movie line. The Cannigma lists paranoia as a possible side effect in susceptible people.
• Heavy sedation — this is the point for some people, and a problem if you have plans.
• Harsh smoke — AllBud says the aroma can turn harsh; well-cured flower helps.

Is G13 good for sleep? For most people, yes — it's one of the sleepier strains in the encyclopedia. Don't drive after using it, and talk to your doctor first if you take prescription medication, are pregnant or nursing, or have a heart condition.

Is G13 Top Shelf? How to Judge a Good Bag

• Ask where the cut came from. With no official breeder, provenance is the only quality signal the name gives you. Treat "the original government clone" as a sales line.
• A current third-party COA naming the lab, with THCA, delta-9 and total THC. Treat 30%+ claims without paperwork as marketing. Ours are on the lab results page.
• Earth, pine and skunk. Real G13 smells pungent and woody. Candy, fruit or loud dessert notes mean you're holding something else.
• Dense, chunky buds with heavy frost — the Afghan structure. Airy, wispy flower is a red flag.
• A proper cure — hay or grass smell means it was rushed, and it'll make the already-harsh smoke worse.

Growing G13

G13 grows like the Afghan indica it appears to be — compact, resin-heavy and fast. Numbers vary by seed line:

• Flowering: about 55–65 days indoors for modern G13 lines, per Weedmaps; JointCommerce says 8–9 weeks. The Cannigma lists a late-October outdoor harvest.
• Yield: The Cannigma lists about 1.9 oz per square foot indoors and about 40 oz per plant outdoors. Sensi's Mr. Nice, a G13 cross, is rated at about 400 g/m² indoors.
• Height and structure: Weedmaps calls the plants compact; The Cannigma says they can stretch and need space and airflow — another sign that "G13" covers more than one plant.
• Feeding: The Cannigma rates it moderately difficult and a heavy feeder, especially nitrogen in veg, and says it tolerates heat around 85°F.
• Mold: dense Afghan buds hold moisture. Keep humidity down late in flower, and outdoor growers should watch for bud rot near harvest.
• Seeds: several seed companies sell G13 seeds, and Mr. Nice is still in Sensi Seeds' catalog. None can prove a link to any lab cutting.

Is G13 THCA Flower Legal?

Under the 2018 Farm Bill, hemp is federally legal when it contains no more than 0.3% delta-9 THC on a dry-weight basis — see the USDA hemp program. THCA flower is sold under that rule. State laws differ and are changing, so check your state before you order. And whatever the label says, THCA flower will show up on a drug test — heated, it is THC.

Shop Premium Flower at Diesel Hemp

• Mule Fuel THCA Flower — our featured pick — heavy, earthy gas and a deep, relaxing evening body, from $59.
• THCA Flower — the full lineup, grown in Colorado by Diesel Hemp and partner farms.
• THCA Pre-Rolls — the same flower, pre-rolled.
• THCA Small Buds — same genetics, smaller nugs, better price per gram.
• What THCA flower actually is — the encyclopedia explainer.

Frequently Asked Questions

Is G13 indica or sativa?

G13 is an indica. Leafly and Weedmaps list it as indica; AllBud calls it a 70/30 indica-dominant hybrid. Either way, it's a heavy, relaxing evening strain.

Was G13 really made by the U.S. government?

There's no evidence it was. The story says it was bred at a University of Mississippi government facility and smuggled out, but Erowid found the federal research grow there produced low-THC cannabis, and Leafly and Weedmaps both call the tale a legend.

What is G13 a cross of?

Nobody knows for sure. Weedmaps lists Afghani as both parents and says the exact parentage is unknown; SeedFinder files it under unknown or legendary genetics. Claims that it comes from Afgoo or Maui Haze aren't supported by any strain database.

What does G13 stand for?

According to the legend, Government strain 13 — Weedmaps lists 'Government Indica Strain 13' as an alias. The name is part of the story, not proof of it.

Is G13 the strain from American Beauty?

Yes. In the 1999 film, a character sells G13 as a potent strain genetically engineered by the U.S. government with no paranoia. MEL Magazine credits the movie with making the strain famous.

How strong is G13?

Leafly lists 20% THC, AllBud 22–24% and Weedmaps 18–24%. The Cannigma's compiled lab results average 16.2%, ranging from 10% to 29%. It feels stronger than those numbers because the high is so heavy.

What does G13 taste like?

Earthy, piney and woody with a skunky edge. AllBud describes a sweet, earthy inhale and a 'surprisingly pleasant' skunky exhale, with hints of berry on the nose.

What are the effects of G13?

Weedmaps users report relaxed (48%), sleepy (26%) and euphoric (26%). AllBud describes a brief euphoric lift that turns into heavy, lazy relaxation.

Is G13 good for sleep?

For most people, yes. Sleepy is one of Leafly's top-reported effects, and AllBud lists insomnia among the conditions users say it helps.

Is G13 good for beginners?

Usually not. Leafly reviewers call it 'not a beginner's flower' and say it can be overwhelming for new smokers. If you try it, start with one small hit.

What strains come from G13?

Sensi Seeds' Mr. Nice (G13 × Hash Plant, 1999) and Barney's Farm's Tangerine Dream (G13 × Afghani × Neville's A5 Haze) are the best known. G13 Haze, Amnesia G13 and HP-13 also carry the name.

How long does G13 take to flower?

About 55–65 days indoors for modern G13 lines, per Weedmaps, or 8–9 weeks per other strain guides. Outdoors, The Cannigma lists a late-October harvest.

Where can I buy G13 THCA flower online?

G13 isn't in the Diesel Hemp shop right now. Our closest everyday pick is Mule Fuel THCA Flower — heavy, earthy and gassy with a deep, relaxing evening body, from $59, third-party lab tested. It runs louder fuel than G13's pine and skunk; for a concentrate, try our HBIC live rosin. Add a pre-roll to ship free over $75.

Related Strains

• Tangerine Dream — Barney's Farm's G13 × Afghani × A5 Haze cross.
• Afghan Kush — the Afghan indica backbone G13 most resembles.
• Black Afghan — another heavy, hashy Afghan-type indica.
• Hindu Kush — a landrace indica Weedmaps lists as similar.
• Northern Lights — the other Dutch-era indica legend.
• Skywalker OG — a heavy OG The Cannigma names as similar.
• Master Kush — an old-school, earthy Kush indica.
• Bubba Kush — a sleepy, earthy evening classic.
• Mule Fuel — our heavy, gassy in-stock pick.
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