Critical Jack feminized seeds


Critical Jack is a feminized photoperiod cannabis strain carefully cultivated by the team at Dinafem Seeds and is one of the most popular strains in the Critical family. If you’re looking for your next powerhouse strain but can’t decide? Look no further because Critical Jack is just right for you.

A Critical + – Jack Herer Hybrid

Growing this strain outdoors is recommended in warmer climates as this strain has a longer flowering period due to her Sativa-dominant genetic lineage. While she has excellent resistance to mould and pests due to her high resin-production, growing in a greenhouse will improve the quality of the harvest. Outdoor crops can be ready to harvest late September/mid-October while indoors this strain blooms in 60 days to yield up to 625 gm2 under a 600 W HPS or LED lighting. Here is some further information to help you make the most of your grow:

  • Medium to tall plant – excellent for both indoor and outdoor growing.
  • Max EC of water – veg: 1.4, flower: 1.8
  • Water pH – 5.8 – 6.0.
  • Best grown in 10 L pots with 70:30 coco coir/perlite mix.
  • Grow room temperature below 26 ˚C to preserve full terpene profile.
  • SCRoG arrangement recommended due to tall branches.

Critical Jack - Perfect for Extracts

This strain has an excellent resin production making this an ideal hash plant – perfect for those looking to make their own cannabis extracts. In fact, this strain won first prize at the 2015 San Bernadino Hempcon Cup in the ‘Best Shatter’ category owing to its irresistible flavour and euphoric, relaxing effect.


  • Brand

    AKA seed bank. They create and preserve cannabis genetics, then we get them to you.

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    Dinafem Seeds
  • Type of seeds

    Regular or feminized. Pick feminized if you want female plants only.

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  • Type of seeds

    Either autoflowering or photoperiod. Both have their pros and cons, but growing autos is easier.

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  • Suitable for growing

    This strain is perfect for growing both indoors and outdoors.

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    Indoor, Outdoor
  • Effect *

    Each strain produces a certain effect on your body. This is what you can expect from this variety.

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    A portion of vivacity and good mood
  • Genetics

    Genetic composition of the strain. Shows parent strains that were used to create this particular variety.

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    Critical+ x Jack Herer
  • Awards

    Exceptional strains receive awards from the industry. If a strain has awards to its name, it's a sign for you to try it.

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    1st Outdoor Sativa, UCLA 2016
    1st Best Shatter, San Bernardino Hempcon Cup 2015
  • Height

    This is how tall the plant can become. Use this info when planning your grow space.

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    Up to 300 cm outdoors
  • Harvest

    This is how much bud you can get from this variety come harvest time.

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    625 g/m² indoors
    1200 g/plant outdoors
  • Indoor flowering time

    The length of the flowering stage for photoperiod strains, or seed-to-harvest time for autoflowers.

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    60 days
  • Outdoor finish

    This is when your plant will be ready for harvest when grown outdoors. Make sure it's still warm enough by then!

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    Mid October
  • % Sativa/ Indica/ Ruderalis

    The ratio of Sativa/Indica/Ruderalis in this particular variety.

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    60% Sativa / 40% Indica
  • THC

    The main psychoactive compound in cannabis. The higher THC level, the more potent the strain.

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    21 %

*Herbies sells cannabis seeds exclusively as souvenirs that aren’t meant for cultivation or germination. Customers should be aware that the germination of cannabis seeds is illegal in most countries. Herbies sells cannabis seeds exclusively for collecting and preservation for future generations. We advise customers to check with their local laws before germination, as Herbies does not accept responsibility for the illegal use of our products.

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  • Mega Puff
    27 November 2019
    27 November 2019
    • Advantages
      Top level! It takes time to grow but it’s absolutely worth it. Just like any other strain by Dinafem
    • Disadvantages
      Takes long time
    • General impressions

      That’s a bomb! It makes me laugh even when i’m alone by myself

  • As if
    25 August 2019
    25 August 2019
    • Advantages
      flowers really fast
    • Disadvantages
    • General impressions

      Great strain with a Sativa effect, I didn’t feel any Indica in it at all. Jack finishes its flowering really soon as well as starts it! on 12/12 schedule it takes only 7-10 days. I used 20l bags with 17l of soil in them, 2 400W HPS. As a result, 700+ grams from 3 plants in several stages of harvesting - the bottoms needed a little longer to finish. Colas are so heavy, after a month of flowering
      they’re gonna need extra support