Critical Jack Seeds
Critical Plus meets Jack Herer for focused, citrusy harvests
$0.00 – $143.654 pack sizes — choose at ILGM
Guaranteed germination · Free US shipping over $50 · Discreet packaging
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Our take
Critical Jack is a sativa-dominant feminized strain bred from Critical Plus and Jack Herer — two varieties known for reliable production and a bright, citrus-forward character. At 19% THC it sits comfortably in the medium range, making it approachable without being underwhelming. It's a good fit for intermediate growers ready to manage a taller plant in exchange for generous yields.
Grow specs
Specs are ILGM's published figures for this product; catalog and pricing last verified August 2026. Our write-up is our own — see how we make money.
Growing notes
Critical Jack grows tall, so plan your vertical space early — topping or low-stress training helps indoors. It performs well in Mediterranean-style outdoor conditions and adapts to indoor environments. Flowering wraps up in 56–70 days inside, with outdoor plants ready around mid-October. Growers with a few harvests under their belt will feel at home managing its structure and feeding needs.
New to growing? Start with the complete guide, plan your gear with tent setups, and diagnose problems with troubleshoot.
Want variety instead?
Mix packs bundle three proven strains (30 seeds) at up to 50% off buying separately — the best value in the catalog.
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