Jack Herer Feminized Seeds

Jack Herer is a balanced feminized hybrid, 50% indica and 50% sativa, with a spicy, pine-scented nose and a savoury hashish taste. Sensi Seeds, who first bred it, calls it a perfectly balanced hybrid with high THC content and vast resin production, and says its THC can exceed 20%. Leafly also lists it as JH, The Jack, Premium Jack and Platinum Jack. It is a moderate grow that flowers in about 10 to 12 weeks, though strongly indica-leaning plants can finish sooner.

History & lineage

Jack Herer carries the name of the American cannabis rights activist Jack Herer, author of The Emperor Wears No Clothes. Sensi Seeds created it in the Netherlands and credits Alan Dronkers as the breeder behind it. It won the 1994 High Times Cannabis Cup, the 7th Cup, as Sensi Seeds’ entry, and High Times’ winners list records a second win for Sensi’s Jack Herer in the 1999 Sativa Cup.

Sensi lists its genetics as Haze x Northern Lights #5 x Shiva Skunk, and Shiva Skunk is itself Sensi’s cross of Northern Lights #5 and Skunk #1. High Times’ history of the Cup described the winning plant as an unstable hybrid of Haze, Northern Lights #5 and Skunk #1. Northern Lights #5, one of its parents, won the Pure Indica Cup at the 1990 High Times Cannabis Cup. The line has carried on in other strains, too: Brothers Grimm’s Cinderella 99 began with a plant called Princess, grown from seeds found in a Jack Herer bud bought at an Amsterdam coffeeshop.

Aroma & flavour

Expect spicy, piney notes over a sharp, savoury hashish tone. Sensi says most buds blend that hash base with Afghan tones and fruity skunk, depending on the phenotype. For Jack Herer as a strain, Leafly users most often report earthy, pine and woody flavours, followed by citrus. The lead terpene is terpinolene, which is uncommon as a lead in cannabis: Leafly’s lab data puts caryophyllene and pinene behind it, and Sensi’s own test grow found terpinolene, caryophyllene and myrcene on top. Our guide to cannabis terpenes explains how those compounds shape a smell.

Effects, as users report them

These are Leafly users’ reports for Jack Herer as a strain, most common first. Sensi itself describes a high-energy cerebral high over a strong body buzz, and calls the effect long-lasting. Dry mouth and dry eyes are the downsides people report most often, and smaller numbers report paranoia, dizziness or anxiety. How it feels depends on the person, the dose and their experience, so if you are new to cannabis, start with a small amount.

Growing Jack Herer

Jack Herer is a feminized photoperiod plant: it stays in vegetative growth until the light drops to 12 hours a day indoors, or until the days shorten outdoors. Sensi puts most plants at around 10 to 12 weeks of flowering, with strongly indica-leaning plants ready after about 8. Most phenotypes grow like sativas, while a rarer indica-leaning one stays more compact. To see how that fits a whole grow, read our seed-to-harvest timeline.

Leafly rates it a moderate grow, and Sensi says it may need a little extra care to reach its full potential. Sensi’s 2007 indoor spec sheet listed a height of about 150–180 cm (4.9–5.9 ft), and plants grow vigorously once flowering starts, so leave room for the stretch. Sensi names supercropping for this plant, and a screen of green (SCROG) to restrict its height gain. Sensi rates it a heavy yielder. Expect indoor yields around 500–600 g/m² (about 1.6–2.0 oz/ft²) and outdoor plants around 600–700 g (about 21–25 oz) each. Outdoors, Sensi says it succeeds only in a warm climate with plenty of sunshine. Near the end, look at the trichomes to judge when to harvest.

Is Jack Herer right for you?

Questions buyers ask