The specs in one line: 17-23% THC, <1% CBD, 8-10 weeks flowering, 500-700g/m² reported. Best indoor or outdoor. easy grow.

Lineage: Jack Herer × Super Skunk × Haze, refined by Sensi Seeds into what became Jack Flash #5 — a feminized strain that leans indica (65%) but carries enough sativa stretch to surprise growers who don't account for vertical space. Indoors it stays manageable; outdoors it can push past two metres, so train early if your tent has a low ceiling. THC typically lands between 17–23%, and yields in the 500–700 g/m² range are realistic under decent light — not a promise, but a honest target backed by the genetics. Flowering wraps in 8–10 weeks, and the ease rating is genuine: beginners report clean runs with minimal fuss. Expect two distinct phenotypes, one stocky and bud-heavy, one taller and airier, both carrying that citrus-skunk scent that sharpens as harvest approaches.

Best suited to Canadian indoor growers who want a reliable, high-yielding feminized strain without a steep learning curve.

Genetics & Lineage

Jack Flash #5 traces its genetics to Jack Flash #5 (Sensi Seeds genetics). This hybrid-dominant feminized seed produces plants that express the best traits of its parent lineage, delivering consistent results for growers of all experience levels. Bred by Sensi Seeds, each seed is selected for genetic stability, terpene expression, and vigor.

Effects & Experience

Users report primarily euphoric and relaxed effects, making this strain ideal for evening use and unwinding after a long day. The body-centered stone builds gradually, easing tension and promoting deep physical relaxation. With THC levels reaching 23%, this offers a well-balanced experience suitable for most users with some cannabis familiarity.

THC Level & Potency

Jack Flash #5 delivers THC levels of 17-23%, placing it in the moderate-to-strong range that most regular consumers find comfortable. CBD content is minimal, so the psychoactive effects are front and center. The onset typically arrives within minutes with a balanced head-and-body experience that evolves over time.

Growing Jack Flash #5

Jack Flash #5 is rated as easy difficulty, making it an excellent choice for first-time growers. The plants are resilient, forgiving of common mistakes like overwatering or inconsistent feeding schedules.

Indoor Growing: Expect a flowering time of 8-10 weeks with yields of 500-700g/m². Plants typically reach 100-180cm indoors. This strain responds exceptionally well to SCROG (Screen of Green) and LST (Low Stress Training), which can boost yields significantly. Maintain temperatures between 68-80°F with relative humidity around 45-55% during flowering.

Outdoor Growing: This versatile strain performs well in both indoor and outdoor environments. Outdoor growers in warm climates can expect harvest from late September through October. Watch for humidity during late flowering to prevent bud rot, especially with the dense, heavy buds this strain produces.

Flavor, Aroma & Terpene Profile

Jack Flash #5 features a fruity, citrus, skunky, earthy terpene profile that develops complexity throughout the flowering cycle. Sweet berry and grape notes dominate the inhale, with a sugary exhale that lingers on the palate. The aroma intensifies significantly during the final 2-3 weeks of flowering — carbon filtration is recommended for indoor grows requiring discretion.

Medical Benefits

While individual experiences vary, Jack Flash #5 is commonly reported to help with stress relief, chronic pain, insomnia, and muscle tension. The deeply relaxing effects make it a popular choice among medical users seeking nighttime relief. As with any cannabis strain, start with a low dose and increase gradually. Consult a healthcare professional before using cannabis for medical purposes.

Who Should Grow Jack Flash #5?

This strain is ideal for beginner growers looking for a reliable, low-maintenance plant that delivers consistent results without advanced techniques. If you're looking for evening relaxation and deep stress relief, this is your strain.

Why Buy Jack Flash #5 from Seennabis?

When you purchase Jack Flash #5 through Seennabis, you are buying directly from Sensi Seeds — The world's oldest cannabis seed bank, founded in Amsterdam in 1985. Every order includes verified genetics, discreet shipping, and responsive seller support. Sensi Seeds has completed over 177 sales.