Feminised Seeds

Critical Jack


A pedigree winning combination

Critical Jack is a feminised cannabis seed deriving from the cross of two cannabis legends: Critical + and Jack Herer. At Dinafem Seeds, we decided to work on these two genetics because we thought that crossing them would lead to a really good thing, and that's what happened. We've masterfully mixed the traits of both genetics until the three legendary families (Skunk #1, Northern Lights and… Read more >
  • Indica: 40%

    Sativa: 60%

  • THC: 15-20%

    CBD: 0.01-0.2%

  • Outdoors:

    • 1200 g/plant

    • 3 m

    • Late September / Mid-October

  • Indoors:

    • 625 g/m2

    • 60 days

  • Critical+
  • x
  • Jack Herer

Perfect for: Growers seeking a tasty, potent and heavy-yielding strain with an unbeatable overall quality

Critical Jack is a feminised cannabis seed deriving from the cross of two cannabis legends: Critical + and Jack Herer. At Dinafem Seeds, we decided to work on these two genetics because we thought that crossing them would lead to a really good thing, and that's what happened. We've masterfully mixed the traits of both genetics until the three legendary families (Skunk #1, Northern Lights and Haze) within this strain became evident. In a nutshell, a high-class hybrid that deserves a very special place in any garden; an amazing reputation earned for her yield, potency, taste as well as for the incredible extractions that can be made out of her super-tasty trichomes.

  • 1st prize -Outdoor category- at the V Copa Cata Zona Norte (Buenos Aires, Argentina, September 2019)
  • 1st prize in the 'Outdoor Sativa' category at the 2016 UCLA cup (Unión Cannábica Latinoamericana).
  • 1st prize in the "Best Shatter" category of the 2015 San Bernardino Hempcon Cup, USA.


Critical Jack turns into marijuana plants that could reach heights of 3 meters outdoors. Their open and branchy structure improves light and air penetration, resulting in better yields of large, thick, rock-hard buds covered in a dense layer of trichomes.


Critical Jack delivers such generous crops that cannabis growers interested in growing big should definitely bear her in mind. In fact, with her, it’s quite easy to obtain crops of up to 625 g/m2 indoors and of 1200 g/plant outdoors. If it’s yield what you want, this strain is meant for you!

Aromas and flavours

Critical Jack delights us with a sweet and intense taste that mixes hints of wood, incense, pine, spices and lemon. A marvelous combination nobody will be able to do without!


Critical Jack reveals a clear Sativa influence on the part of Jack Herer: her effect, potent and long-lasting, fills you with energy and joy. On top of that, it’s got a psychedelic point that will awaken all your senses. As one would expect from a 60 % Sativa-dominant hybrid, she’s more cerebral than physical, perfect for opening your mind and helping you think clearly when, for instance, you need to initiate interesting discussions or simply carry out your daily chores. Whatever it is what you need to do, this strain will make you feel just right.


Critical Jack rewards the attention and care received with vigorous plants that grow very quick (some 60 days), the best results being in SCROG and in SOG. The most suitable places for cultivating her are the ones with dry, sunny and temperate Mediterranean climates or in the greenhouse. In view of her dimensions and her intense aroma, she's best grown outdoors, particularly in guerrilla growing, in a greenhouse or somewhere where you can grow without worrying about attracting attention. This resistant strain copes well with insect and moisture attacks, even when there is constant rain.

Characteristics of
Critical Jack cannabis seeds

Genotype40% Indica / 60% Sativa
CrossCritical+ x Jack Herer
Indoor flowering60 days
Indoor yield625 g/m2
Outdoor harvest timeLate September / Mid-October
Outdoor yield1200 g/plant
Outdoor height3 m

*Cannabinoid content (THC, CBD…) may vary depending on external factors such as the growth medium, the grower’s experience, the growing technique (SOG, SCROG…), the environmental conditions and genetic variation.

Dinalab Analysis


Total amount of cannabinoids*: 17.39%

*Cannabis contains at least 113 cannabinoids, which can be either acidic or neutral. When heated – e.g. through smoking, vaping or cooking – acidic cannabinoids decarboxylate and become neutral. This report refers only to the main cannabinoids – acidic and neutral – in this strain.


Total amount of terpenes*: 2.567%

*Cannabis contains over 100 terpenes. These compounds create the aroma unique to each strain and can interact with cannabinoids. This report refers only to the 15 most abundant terpenes in this strain.

These results have been obtained by liquid chromatography coupled to a UV-visible HPLC Detector (HPLC-UV/VIS) for identifying the cannabinoids and by gas chromatography coupled to a flame ionization detector (GC-FID) for the collection of terpenes. The equipment has been previously calibrated and quality control samples were run to assure the accuracy of the results. The data shown here is the average of samples coming from several plants grown from seeds by different growers.

The data contained within this report was collected in accordance with the requirements defined by the United Nations Office on Drugs and Crime in their Recommended Methods for the Identification and Analysis of Cannabis and Cannabis Products. We hereby attest that the information contained within the report has been reviewed for accuracy and checked against the quality control requirements for each method.

What do our customers think?

120 customer reviews
4.93 out of 5 (based on 120 ratings)

All reviews about Critical Jack:

  1. Topp site.. En top product topp Critical jack

    5 out of 5
    Topper product hebben jullie heb vroeger 2015 ook bij mijn bestellingen ook mooi zwarte shirt met dinafem er op.. Heb ik nog steeds.. En heb de zaatje van critical jack doen ook goed topp site
  2. Master

    CheckmarkA "verified" checkmark Verified purchase
    5 out of 5
    Growing in a garden in England in 2018. A wonderful easy to grow plant. I grew in coco substrate and it yielded about 180 grams plus only one plant. Sadly I couldn't finish the last two weeks because of being dismissed from watering and the plant went dry in the late stadium. Still the smoke was a refined high quality with a very long-lasting pain killer effect. Exactly what I needed at this time. For early starters not even in England rainy weather any problem.
  3. Mr

    5 out of 5
    Ive seen a friend grow a pair of critical jack The leave are fat and vegy The node spacing is ideal for outdoor Overall its one sexy ass plant man !!
  4. critical jack

    5 out of 5
    amazing cross.. well balanced in every way.. she is just what her name says, tok best of both parents and that is critical jack for you... it's one of those strains no newbie experiments can harm..no matter what technique, nutrients...etc..you use, you'll get decent quantity and quality.. if you know what you are doing and have some experience with this plant, i'm sure you'll get high quality rock hard buds with potent smell and aroma..."bag appeal" is 10/10,yield high and 50:50 sativa:indica balanced high... critical jack is probably one of 3 best strains dinafem ever made...
  5. A Must for all Sativa Lovers

    5 out of 5
    So, I got this as a free seed when ordering from Original Sensible Seeds. I started it under lights before putting it in the Greenhouse. It was a lot early in the season (the end of winter to be specific) so it went into flower. After about 9 weeks it just kinda paused (light hours rising), so I harvested most of it and left a couple of nodes for reveg. That 8 grams was some of the best smoke I'd had in a while. And I was WRAPPED I didn't just pull it. She ended up 8 feet tall, final trimmed weight on harvest was 1.2kg. Large internode spacing defeats any attempt at mould getting a hold, handles just about any nutrient regime you can throw at it, and is amazingly easy to look after. As you described though, she's a stretchy girl, thanks to the Herer genetics, so Supercropping, LST or SCRoG are ideal. The massive Citrus hit on partaking is accompanied by what could be described as a shotgun blast to your forehead, right between the eyes, immediately wiping any thought process underway. After that, it feels deceptively light until 5 minutes later, when it just keeps building a cerebral buzz until all that is, is Critical Jack. This is one of the top 3 strains of the less than a dozen strains I run as my staple fare, and if you're smart, you will too. This is the strain that sold me on the quality of your breeding program, and the quality of the genetics you produce. Your sales and service are impeccable, and I recommend you to anyone shopping for Serious quality. Much respect Dinafem. Fan for Life.
  6. Mr

    CheckmarkA "verified" checkmark Verified purchase
    5 out of 5
    I really like this strain. This strain made alot hard and dense nuggets with full of sugar, and very easy to grow. And its strong smoke good for veterans and good for newbies.
  7. just keeps on giving

    CheckmarkA "verified" checkmark Verified purchase
    5 out of 5
    uk grow,returning buyer,the amount and quality is without doubt outstanding.easy to grow,with a cbd level thats a instant hitting.body numbing pure pain relief ..high in thc this allrounder is a must for all uk growers! disapointment is not inc
  8. critical jack

    5 out of 5
    critical jack is art okant its hgh quality seeds . dinafem seeds is n umber one company for me <3
  9. GREAT

    5 out of 5

    Tastes perfect, Just great

  10. Excellent hybrid!

    5 out of 5
    Excellent hybrid and one of my new faves! Very balanced high-relaxing both body and mind. But not too heavy that you're stuck on the couch. The high for me is very uplifted but relaxed. Helped a lot with my depression and anxiety. Definitely recommend it for people looking to treat those problems!
  11. Totally recommended!

    5 out of 5
    Not for nothing the Critical Jack is one of my favorites! I created a reggae band with his name. I wanted to pay Dinafem's name rights but they opposed it. : p Giant plant, abundant production, high quality and in a short time. Complex aromas and flavors, unique and very characteristic of the Critical Jack. I had Critical Jack in climates of extreme humidity like in Argentina, tropical climates like Brazil, and cold of 4 degrees in Germany, and yet the Critical Jack always adapts and gives good results. I totally recommend Critical Jack
  12. Outdoor London

    4 out of 5
    I tried to grow it in London in a self-made greenhouse. But too cold to get big crops. Strain wouldn't develop the big boost in the second stage of flowering. So crops are rather disappointing but high is great. Very strong and influential.
  13. awesome strain

    5 out of 5
    By accident i super cropped this strain{harvested twice} i got 3.5 oz the first time and 8.5 oz the second which you may find hard to believe if you've never super cropped but i shit you not. This is the best strain ive grown in 15 years. lovely smooth smoke and the high lasts at least 4 hours. I grew in coco with canna nutes and a 600 hps. I re vegged after the first harvest by putting what was left of the plant on a 24hr cycle and i have never seen anything grow as vigorous as this. At 1 point i thought it was gonna go through the roof of my tent and thats with topping every 2 days. Unbelievable crop and the next 1s already ordered. Nice 1 dinofem,i will investigate more of your strains after this.
  14. Unbelievable yield

    5 out of 5
    I monster cropped this strain and grew in coco. 20litre pots l, canna nutes. 8. 5 ounces dry. No bullshit. This strain is awesome. It just wouldn't stop growing. Will definitely grow again.
  15. Must grow this plant

    5 out of 5
    Second time growing this plant .i have 5 baby's ATM all look really healthy and shinny .can start to smell the buds after 7 weeks .. they are not massive but they do seem to explode nearer the end off growth ..great taste ,always have people wanting more
  16. Must grow this plant

    5 out of 5
    Second time growing this plant .i have 5 baby's ATM all look really healthy and shinny .can start to smell the buds after 7 weeks .. they are not massive but they do seem to explode nearer the end off growth ..great taste ,always have people wanting more
  17. critical jack

    5 out of 5
    Grew 3 outdoor in the central valley of California. I was very impressed by the quality of genetics used to create this strain. Loaded with trichomes and smells very dank. Depending on root space these girls will spread. Reacts well to lst, bending, and a good canidate for scrog. High is up. I like it for daytime medicating. Great for getting work done, no couchlock at all. **Heavy doses for inexperienced users may cause increased heart rate and paranoia**
  18. Top shelf material

    5 out of 5
    Massive yields with strong lemon sherbet smell in 8/9 weeks. Stretches 3 to 4 times start of 12 hour, good hight for max scrog yield is 120-140 cm. 1000w avg. 850g m2, 1kg possible on nft.Easy clone but not the most lush to begin.Can cope with poor environmental conditions, carbon filter essential.Watch out for rot, have plenty of air circulation.Up there with the best if grown well.Peace, Lamb Chop.
  19. Best in class!!!

    5 out of 5
    This strain is unreal! My average was 3.06oz per plant. Some were huge, over 4oz. This is the one! All rounder, the smoke is amazing!
  20. Well worth growing.

    5 out of 5
    A trouble free plant to grow. I grow organic and this plant made a very strong satisfying smoke that I shall grow again.
  21. top quality strain

    5 out of 5
    superb strain great to smoke and unique flavor
  22. critical jack!!!!!!

    5 out of 5
    This strain is absolutely one of my all time favs as a gardener! this plant has very fast finisher phenos that produce 6-10 ozs of some fine fruity product in 6weeks! the critical in it makes it very user friendly and not to difficult to grow, it has amazing structure with the most compact buds ive ever grew! looks can be deceiving with this girl! her buds are heavy and sparkle with thrichomes with a lemony fruit smell! wheather your new to the garden seen of an experext, expect amazing things with this girl! THC avg 16-20% depending on the color of your thumb ;-)!!!
  23. amazing

    5 out of 5
    i have been buyed one pack of 3 seeds and i have buyed because i try it and i love it its awsome and taths a great plant productive balanced fast got all awesome plant really first comment guys ;)
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