Sativa seeds come with more jargon attached than any other category of cannabis seed, and most of it says one thing to a botanist, another to a breeder and something different again to the grower trying to make a decision in front of the listing. A disappointing sativa grow usually goes back to a word that was read in the wrong one of those senses: a flowering time taken as a fixed number, a "sativa-dominant" label taken as a statement of effect, a landrace chosen as if it were a tent-bred hybrid. The entries below are written with the range at https://hazesativaseeds.com to hand for reference, since it leans heavily towards the classic end of the spectrum and that is where the vocabulary matter most; the definitions though hold to any sativa seed from any shop. They are in no special order, since none of them makes usable on its own without the others.
Stretch (the doubling)
The burst of upward growth that follows the switch to flowering. Indica-leaning plants gain around half their height again; sativas commonly double, and a few equatorial types go further. The stretch continues two to five weeks and cannot be stopped after it has started, merely bent sideways by training.
In practical terms, the stretch multiplier is the number worth reading before deciding when to flip. A sativa switched at sixty centimetres in a standard tent is touching the lamp before week four of flower; one flipped at thirty centimetres centimetres has room. People coming from indica strains almost always switch far too late the first time, and the consequence is visible on the ceiling of the tent.
Terpinolene (the "sativa smell")
A terpene found in high proportion in a lot of old sativa strains and responsible for most of the thing people mean as the "sativa" smell: fresh, woody, citrus and faintly floral at once. It is volatile, driven off quickly by fast drying, and it degrades faster in the cure than the earthier terpenes which lead indica-leaning lines.
To a seed buyer the word does two jobs. When a listing lists terpinolene among the lead aromas, the line most likely has substantial old-sativa ancestry regardless of what the label says. And when the grower wants that smell to survive to the jar, the cure has to be slow and cool; a fast dry turns a terpinolene line to a flower that tastes of very little and no trace of what the pack promised.
Flowering time (and what it is counted from)
The figure of weeks between the start of flowering and maturity, which is the single most misread number on a sativa pack. For photoperiod seed it is measured from the day the light is cut to twelve hours, not from germination, so a "fourteen-week" sativa started after an ordinary vegetative period is a twenty-two-week plant. Seed companies also quote the optimistic end of a range, because the other end sells fewer seed.
Long-flowering plants take everywhere from ten weeks to well over twenty, and the longest line in the Haze Sativa Seeds range comes in at around 16 weeks from the flip. The catalogue can be filtered by this figure, which is a reasonable first pass if you have a room with a fixed schedule. A grower who allows four weeks on top of whatever the pack states is seldom disappointed.
Latitude (outdoor sativas)
The one figure that determines whether a sativa can finish outdoors, and a number that no pack prints. Equatorial lines require the run of shortening days to continue late enough for the plant finish; in high latitudes the frost comes before that, and the grower cuts an unripe plant in the end of October or loses it to mould in November. A closer south, in the northern hemisphere, the longer the season runs, and Mediterranean and subtropical growers can finish plants that temperate gardens cannot.
The usable rule for a seed pack: an "outdoor" sativa harvest date is stated for the breeder's home latitude, normally somewhere in temperate Europe or the western United States, and every step further north of that pushes the date later into the frost. A grower north of about the fiftieth parallel who is after a long-flowering sativa in the garden needs to be shopping for a sativa autoflower or a greenhouse, not a longer season.
Landrace
A population of plants shaped over centuries to one place by the local growers and climate alike, and not by deliberate selection. Thai, Colombian, Congolese and Mexican stock are the classic sativa cases. A landrace is a spread, rather than a single plant: inside a pack the flowering times, flowering times and aromas spread widely than in a tent-bred line, and that spread is the whole value of growing one.
The mistake is buying a landrace like a modern hybrid. It carries habits that make sense in an equatorial field, such as a frame no tent can hold and a flowering rhythm tuned to an equatorial daylength the majority of growers never provide. "Heirloom" on a listing usually means a landrace that has been reproduced away from its origin for some generations, often with a degree of selection for indoor life; it is closer to usable but nonetheless far from a hybrid. A seller offering "landrace" without an collection point and a generation history is applying the word loosely, and the pack should be priced with that in mind.
Sativa-dominant
A catalogue category rather than a botanical one. The phrase usually means that the larger share of a hybrid's parents are classed as sativa by the breeder who drafted the listing, and sometimes means nothing more than that the buds are longer or the aroma sharper than the that breeder's indica-labelled lines.
The effect people associate with a word, lively rather than heavy, is driven far more by terpene chemistry and the cannabinoid balance than it is by ancestry, and a good number of "sativa-dominant" hybrids deliver a heavy sleepy effect while plenty of indica-labelled stock deliver the opposite. To a grower the percentage is worth something for a loose guide to growth habit, flowering time and stretch; for a predictor to how it feels it is next to useless unless accompanied by the aroma description.
Foxtailing
The tendency of some flowers to push out new calyx clusters on top of old ones, producing towered, open buds instead of round ones. In most indica-leaning strains it is a stress symptom, typically from light too close or a room too high, and the advice is to correct the room.
In many sativas, above all Thai and some Haze lines, it is built in and will happen in a flawless room. A first-time sativa grower frequently wastes a month hunting a fault that is not a problem, dropping lights and temperatures and slowing an already slow flower further. The breeder seldom says which kind to expect; the parentage generally tells you.
Equatorial
Refers to lines out of latitudes in which daylength barely varies across the year, and that the plant does not evolved a sharp reaction to shortening days. These lines frequently start flowering reluctantly under a conventional twelve-hour light cycle, because twelve hours is, for them, an unremarkable day rather than a signal.
The working response, passed down among sativa growers for decades, is to shorten the light further: eleven hours, sometimes ten, particularly during the last weeks. It loses a yield yield and gains an more clearer finish. A listing which says "equatorial" is warning you about this with one word, and a grower who reads it as mere geography misses the point hidden in it.
Intersex tendency
The appearance of pollen-bearing flowers on a female plant, usually late in flower and often in response to stress. Every cannabis line carries some tendency for it; sativa plants express it more, and the reason is one plain reason: sixteen weeks of flower is fourteen weeks of opportunity for a timer leak, a temperature spike or a late watering to trigger it off, and an old plant has already gone beyond its intended finish often produces a few late pollen flowers on its own as a final attempt to set seed.
Not one of these makes a sativa line unstable as a matter of nature; it makes the room's discipline matter over longer. A sealed room, steady temperatures and harvesting when the plant is ready and not two weeks later remove most of the problem. A listing that mentions the breeder tests parents for hermaphrodite traits is worth worth hearing for a sativa than on any other category.
Haze (the family, not the smell)
Originally a particular line of plants put together in 1970s California from Mexican, Thai and South Indian landraces, and then kept and worked in the Netherlands. A true Haze runs tall, fills out openly, takes for twelve to sixteen weeks and smells of incense, citrus and something metallic that no line quite has.
In its second sense "Haze" is whatever hybrid which carries a share of that family, and by now is a great many of the sativa-leaning market. A listing which says "Haze" without lineage could be mostly percent the classic family or a small fraction of it, and the grow character tracks the fraction, not the name. The working question is never "is it a Haze" but "how much, and through which parent".