Strain Review: Black Jack By Nirvana Seeds
3 min

Strain Review: Black Jack By Nirvana Seeds

3 min
Black Jack by Nirvana Seeds is a magical blend of two legendary strains that melts away pain and stress in an instant. Read on to find out why this standout deserves a place of honour in your garden.

With Black Jack, you'll get all the best traits from two of the world's best medical-grade strains, Black Domina and Jock Horror. Each one sits on opposite ends of the cannabis spectrum, satisfying very different needs. Black Domina erases stress and pain almost immediately with a near-narcotic, couchlocking stone, while Jock Horror lifts the mood and relieves depression for hours. Black Jack, the result of this epic pairing, is reported to be a sheer pleasure to grow and to smoke. Want to know if those claims are true? Let's find out!


To start our Black Jack grow, we planted a 10 pack of feminized seeds from Nirvana directly into small pots filled with damp soil, covered them with a dome to keep the humidity levels up and placed them on a heating map for warmth.

The first seedlings broke the surface on the fourth day, and by the sixth, all but one was standing at attention with unfolded cotyledons. Just when we were about to give up on the straggler, it popped up on the eighth day. She was a little slow to start but quickly caught up with the other Black Jack seedlings and didn't show any signs of being stunted.

As the vegetation period continued, our young Black Jack plants grew rapidly, and we topped them once the fourth set of true leaves started to unfold. They recovered in a few days and started to grow new branches from both the pinched top and the lower nodes. We decided to low-stress train (LST) half of our youngsters and let the others continue to grow naturally to see how it would affect the final yield.



Nirvana Seeds




Black Domina x Jock Horror

Flowering Time:

9-11 weeks





Yield (indoor):

400-500 g/m²

Harvest Time (Outdoor):


Available as:

Feminized seeds


After about six weeks, we repotted our Black Jack testers into their final containers, added some stakes in anticipation of high yields, and moved them into the flower tent under a 1000 watt HPS set to a 12/12 schedule. They appeared to adjust to the stronger light almost immediately and new growth was seen every day for the next two weeks. The plants that were only topped stretched a lot more than the ones that were LST'd, but they still stayed fairly short and compact. Random branches wanted to grow into the light as pistils started to show, but they seemed happy enough after we tied them down.

Nirvana says their Black Jack is a nine-weeker, but we let ours go a little past 10 because we weren't seeing a lot of amber at nine, and it's always nice to see if you get any last minute swell. Our patience was rewarded with more mature crystals, but the yield didn't appear to change at all. The buds themselves were well-formed, almost perfectly rounded with marble-sized calyxes and no shortage of visible crystals. Colors ranged from bright to dark green with some of the foliage changing to a very deep, almost black green tone as harvest time approached.

Overall, Black Jack was very easy to grow. Our plants reacted well to our training methods, the buds densed up nicely, and they weren't fussy about watering or nutrient schedules. Once dried, the yields ranged from two to three ounces per plant on the ones we simply topped to nearly four from the plants we LST'd. All in all, this was a very satisfying, trouble-free experience and we all agreed we wouldn't hesitate to grow Black Jack again.


When smoked, Black Jack's high quality level is instantly noticeable as the smooth smoke slips across your palate like crushed velvet. The taste is a mix of rich fruit and herbs that's heavy, robust and very pleasant. Unlike many other types of cannabis, Black Jack retains the same flavour from inhale to exhale, and some say this is a sign of good breeding. All we know for sure is that our buds were delicious!

With a background that includes both Skunk and Haze, Jock Horror's strong smell can be almost overwhelming, but Black Domina tempers Black Jack aroma with her own notes of dried fruit and spicy pepper for a more delicate, multi-layered fragrance. We wouldn't call it discreet, but it is toned down and much more mellow. For us, the combination is way better than either of the parent strains on their own.


When we tried out Black Jack, we got exactly what we were expecting. This blend mixes Black Domina's heavy body stone with Jock Horror's racy euphoria to make for a very balanced experience. The buzz starts off with an almost instant numbing sensation that spreads quickly across the face before it flows out to the rest of the body in waves. It's very mellow but never quite reaches couchlock status thanks to a moderate amount of energy from this strain's sativa influences.

We thought Black Jack had the perfect mix of relaxation and motivation. Our most anxious tester reported a nice sense of calm with absolutely no nervousness or paranoia, but we all ended up with a bad case of cottonmouth and some seriously red eyes. Unless you're a constant smoker, Black Jack is way too strong for a workday smoke, but it's a great choice for weekends or chill evenings where you'd like to take the edge off but still be able to somewhat function. Medically, we wouldn't hesitate to recommend Black Jack for pain, stress or even depression.


Black Jack by Nirvana Seeds is powerful mixed hybrid with a satisfying blend of physical chill and happy head highs that's truly enjoyable in almost every way, minus the extreme cottonmouth. She's a superior choice for indoor gardens, especially if you usually grow from seed. We'd grow it again and give her our highest recommendation to both beginners and seasoned growers.

Stars: 5/5



Written by: Laura
Featuring as a regular guest writer, Laura lives in the wild heart of the American East Coast. Based at her family farm, she has developed a deep respect for cannabis, continuing to master and hone its cultivation.

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Luke Sumpter
Luke Sumpter
With a BSc (Hons) degree in Clinical Health Sciences and a passion for growing plants, Luke Sumpter has worked as a professional journalist and writer at the intersection of cannabis and science for the past 7 years.
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