XJ-13 by Unknown or Legendary
Nobody really knows exactly who first bred XJ-13, but this clone-only legend has been a staple of the Southern California scene since the late 2000s. Often described as a "garden rescue" that got passed around dispensaries and early hubs like Oaksterdam, it’s a brilliant cross of Jack Herer and G13 Haze. The result is a modern classic that somehow perfectly balances the soaring, cerebral euphoria of a pure Haze with the heavy, grounding body stone of G13. It’s the kind of weed that gets you up and moving, but keeps your body feeling completely relaxed.
If you manage to snag a legitimate cut of XJ-13, you need to be prepared for some serious vertical growth. She grows tall and lanky, so you absolutely have to top and train her if you want to keep your canopy manageable and push out multiple main colas. She usually finishes flowering in about 8 to 10 weeks, but you have to keep your environment completely dialed in. Guys on the forums always warn about her sensitivity to light leaks, which can easily trigger intersex traits if you aren't careful. She's a heavy feeder, but push the nitrogen too hard and she'll burn up quick.
When you get her right, though, the harvest is unbelievable. The colas get incredibly dense—so dense you have to watch your humidity like a hawk in late flower to avoid bud rot. The aroma is pure, unadulterated "Jack" terps: a loud, spicy, piney smell backed by a sharp, sweet hit of Lemon Pledge. It's a slightly finicky plant that demands an intermediate grower's attention, but the reward is some of the most functional, flavorful smoke to ever come out of the West Coast.
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Similar strains
| Breeder | Unknown or Legendary |
|---|---|
| Type | mostly sativa |
| THC | 17.83% |
| CBD | 0.30% |
| Environment | Indoors |
| Lineage | G-13 × Jack Herer |
| Descendants | NorStar Genetics - Kogi, X Æ B-M04, 13th Warrior, Animals XJ-13, Alien Afterburner OG, NorStar Genetics - Sugar Kiss |
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Growing XJ-13: what to expect
As a sativa-leaning plant, plan for a big stretch after the flip (often 100–200%) — flip earlier than feels natural and keep training options ready. Sativa-leaning plants also generally prefer a lighter feed than heavy indicas. Growers familiar with G-13 or Jack Herer will recognize much of its behavior. Whatever the listing says, the cut in YOUR tent is the ground truth: log feedings, readings, and photos, and let the trends — not the label — drive decisions.
XJ-13 FAQ
Is XJ-13 an indica or a sativa?
XJ-13 is listed as mostly sativa.
What are the parents of XJ-13?
XJ-13 was bred from G-13 × Jack Herer by Unknown or Legendary.
How strong is XJ-13?
Reported THC for XJ-13 is 17.83% and CBD 0.30%. Actual potency depends heavily on environment, harvest ripeness, and cure quality.
What environment does XJ-13 like?
Standard cannabis bands work well: VPD 0.8–1.1 kPa in veg and 1.0–1.4 kPa in flower, with humidity stepping down from 65–75% as a seedling to 40–50% in late flower. See the stage-by-stage table on this page.
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