Double Black

Double Black Feminised Cannabis Seeds by G13 Labs

Double Black is a 100% indica feminised cannabis seed that delivers the deep, heavy relaxation of pure Afghani genetics — doubled down. Developed by G13 Labs, this strain crosses Black Domina with itself, concentrating everything that made the original a late-'90s classic into a shorter, denser, crystal-coated plant. If you want old-school hashish vibes without the guesswork, this is where you start.

Why Double Black Feminised Seeds Stand Out

Double Black exists because G13 Labs looked at Black Domina — already a heavyweight indica built from Northern Lights, Ortega, Hash Plant, and Afghan SA — and decided it needed reinforcing. By crossing Black Domina with another Black Domina, they've locked in the Afghani lineage with 90% phenotype stability. That's unusually consistent for a photoperiod strain. You know roughly what you're getting before the first seed cracks.

The original Black Domina dropped in 1998, right when Amsterdam's seed scene was hitting its stride. We've watched strains come and go since opening our doors that same year, and the pure Afghani indicas have never really fallen out of favour with growers who value reliability over hype. Double Black is that philosophy distilled: no exotic crosses, no flavour-of-the-month terpene chasing — just solid indica genetics doing what they've always done.

One honest note: this is a pure indica with no sativa influence to speak of. If you're after something with a bit of cerebral lift or daytime energy, Double Black isn't it. It's built for evening use, full stop. That's not a flaw — it's the entire point. But it's worth knowing before you commit your grow space.

Double Black Aroma and Flavour Profile

Crack open a cured bud of Double Black and you'll pick up mango first — sweet, almost tropical — followed by a cool peppermint undercurrent that clears the sinuses. It's an unusual combination that makes more sense when you remember the Afghani lineage: those sweet, resinous hashish notes have always carried a surprising range of terpenes beneath the surface.

The smell is distinctly old-school. If you've ever handled proper Afghan hand-rubbed hash — the dark, sticky kind that used to circulate through Amsterdam coffeeshops in the early 2000s — Double Black's fragrance will feel immediately familiar. Dense, earthy, with that sweetness sitting on top like a varnish. The crystal coverage on the buds isn't just decorative; it's where all that aroma lives, locked in trichomes that practically glitter under a loupe.

Growing Double Black: What to Expect

Double Black finishes flowering in approximately 55 days — noticeably faster than many photoperiod indicas, and a genuine advantage if you're running multiple cycles per year or working with limited patience. The plants stay compact at around 140cm, which makes them manageable in tents as small as 80x80cm without aggressive training.

Indoor growers can expect around 500g/m² under proper lighting and feeding — that's a strong return for a 55-day flower cycle. Outdoor cultivators in warmer climates have reported up to 1000g per plant, though that figure assumes full sun, good soil, and a long enough season to let the plants veg out properly before flipping.

G13 Labs specifically notes that Double Black works exceptionally well as a mother plant for clones. The 90% phenotype stability means your cuttings will behave predictably, which matters enormously if you're scaling up or want to lock in a particular pheno without hunting through dozens of seeds. If you find a keeper, you can run it indefinitely.

Double Black Cultivation Tips

1. Start seeds in a propagator or damp paper towel at 22-25°C. Feminised seeds from G13 Labs have strong germination rates, but warmth and moisture are still non-negotiable.
2. Transplant seedlings into their final containers once the first true leaves appear. For indoor grows, 11-litre pots work well given the compact 140cm stature — no need for massive containers.
3. Veg for 3-4 weeks under 18/6 lighting. Double Black stays short and bushy, so a brief veg period is usually enough. Low-stress training (LST) can open up the canopy and boost light penetration to lower bud sites.
4. Flip to 12/12 when you're happy with the plant structure. The 55-day flowering countdown starts from the first visible pistils, not from the light switch.
5. Watch humidity during weeks 5-8 of flower. Dense indica buds plus heavy crystal coverage equals a real risk of bud rot if relative humidity climbs above 50%. Good airflow and a dehumidifier are your best friends here.
6. Flush with plain water for the final 7-10 days before harvest. Those mango and peppermint terpenes come through much cleaner when residual nutrients aren't muddying the flavour.
7. Dry slowly in a dark room at 18-20°C and 55-60% humidity for 10-14 days. Cure in glass jars for at least two weeks — the Afghani sweetness deepens considerably with patience.

Double Black Effects: Deep Indica Relaxation

Double Black induces what can only be described as a deep, physical, full-body calm. This is a strain bred for the end of the day — the kind of indica that makes your sofa feel like it was custom-moulded to your body. The effects are profoundly relaxing, and many growers specifically cultivate Double Black for its reputation as a sleep-friendly variety.

The Afghani lineage is doing all the heavy lifting here. Northern Lights, Ortega, Hash Plant, Afghan SA — each of those parent strains is known for producing heavy, sedating effects, and Double Black concentrates all four bloodlines through the Black Domina cross. There's no sativa-side cerebral stimulation to keep you awake; this one is firmly in the "body" category.

According to a growing body of literature, there is real evidence of the pharmacological potential of cannabis and cannabinoids in various therapeutic contexts (PMC6937300). Research into cannabis-derived compounds also suggests varied effects depending on the cannabinoid and terpene profile present — and Double Black's dense trichome coverage suggests a rich phytochemical mix. According to research on hemp-derived compounds, beta-myrcene — a terpene commonly found in Afghani genetics — has shown significant anti-inflammatory effects in laboratory studies (PMC11085560).

Double Black vs Other Indica Seeds

If you're weighing up your indica options, here's how Double Black compares to two other popular choices in the catalogue:

Double Black's key advantage is that 90% phenotype stability combined with the breeder's specific recommendation as a mother plant. If cloning is part of your operation, that's a meaningful differentiator. Northern Lights brings a touch of sativa heritage for slightly more cerebral effects; Afghan Kush stays shorter but yields less. Double Black sits in a sweet spot between the two — productive, predictable, and properly heavy.