Type 1, 2, 3 and 4 Cannabis, Explained Like a Human

Walk into the modern hemp world and you'll hear flower described by number: Type 1, Type 2, Type 3, Type 4. It sounds like jargon. It's actually the single most useful vocabulary a flower buyer can learn, because it tells you what a plant will do before you know anything else about it.

Here's the system, where it came from, and what each type is actually like, from a grower who's worked with all of them.

Where the type system comes from

The idea goes back to plant science. In 1973, researchers Ernest Small and H.D. Beckstead proposed grouping cannabis plants by their chemical phenotype, or chemotype: THC-dominant, CBD-dominant, and the intermediate plants expressing both. Later research added a fourth group for plants dominant in CBG, and the shorthand Types 1 through 4 stuck. It's not an official standard run by any agency; it's the working language growers and breeders use because it describes chemistry, which is what actually matters.

Erich, the grower behind Flow Gardens, who works with nearly 300 strains, gives the plain-English version:

• "Type 1 flower is basically all THC, with just a hint of CBD, if that."
• "Type 2 flower is either equal parts of CBD and THC, or most likely two parts CBD, one part THC."
• "Type 3 flower is the opposite of Type 1. It's almost all CBD, with a THC level 1 percent or below."
• "Type 4 flower is CBG, which has virtually zero THC, and then CBG anywhere from 10 to 20 percent."

One nuance worth adding to his Type 2 definition: in plant science a true intermediate plant tends toward roughly equal THC and CBD, and a plant like that can't qualify as hemp. The Type 2 flower sold in the hemp market leans CBD, commonly around two to one, which is what keeps it on the right side of the line. Same family of plant, tilted toward the gentler side.

Type 1: the classic

THC-dominant flower is what most people mean when they say cannabis: the classic, psychoactive experience. In the hemp market, Type 1 means THCa-dominant flower, and it's part of the Flow Gardens lineup. The rules around it are changing: from December 11, 2026, the federal total THC standard counts THCA, so check the current rules where you live. The change is covered in our December rule explainer, and the current strains are in the Type 1 collection.

Type 2: the balanced middle, and the type that made us

Type 2 is flower with meaningful amounts of both cannabinoids, and it has a devoted following for a reason: users describe the effects of THC with the edges sanded off, which many attribute to the CBD riding alongside.

It's also personal history here. "It was probably early 2021 when we started releasing our Type 2 strains, and that's kinda what put us on the map," Erich remembers. One launch, a strain called Banana Mac, hit the site so hard there were 450 people on the store at once and it oversold instantly. Flow's Type 2 genetics, Butterberry and Blue Cheese among them, went on to take medals at the Emerald Cup in open competition.

The December 2026 total THC rule lands hardest on this category, which is why Erich is currently finishing one final run of nearly all his Type 2 genetics. If you've been meaning to try the category that built our reputation, this year is the time.

Type 3: CBD flower, the everyday one

Type 3 is CBD-dominant flower: the relaxation-without-the-high option, the one suited to daytime, to THC-sensitive people, and to anyone who wants the ritual and flavor of flower without impairment. It's the core of the Flow Gardens lineup and the focus of our breeding program for the new total THC era. We've written a full guide to it, and the strains live in the Type 3 collection.

Type 4: CBG, the different one

Type 4 flower is dominant in cannabigerol, the cannabinoid every other cannabinoid starts as, which is why chemists call it the mother cannabinoid. It's naturally very low in THC, which makes it the most future-proof flower there is under the new rules.

What's it like? Smooth and creamy in flavor, sometimes with a menthol note, and with a character regulars describe as lighter and brighter than CBD. See what's currently in the Type 4 CBG collection.

Fun fact from the breeding side: CBG flower is notoriously low on smell, so when this year's phenohunt turned up two Key Lime CBG plants that actually smell of key lime, they went straight into the mother room.

Whatever type you land on, the same three rules apply: buy from a source you can verify, check the COA, and trust your nose. We've written a cup winner's checklist for exactly that.