UltraSour by TH Seeds
Growers reach for UltraSour as an indica-leaning option, a cross of Mk-Ultra × Sour Diesel out of TH Seeds. Indoors it typically finishes flowering in around 63 days after the flip to 12/12. The environment targets below are the same stage-by-stage bands the Cultivar journal grades real UltraSour grows against.
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Similar strains
| Breeder | TH Seeds |
|---|---|
| Type | mostly indica |
| Flowering time | ±63 days |
| Environment | Outdoors |
| Lineage | Mk-Ultra × Sour Diesel |
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Growing UltraSour: what to expect
As an indica-leaning plant, expect a modest stretch after the flip (roughly 50–100%) and dense bud structure — which makes late-flower humidity discipline the main risk: keep RH in the 40s once buds fatten to stay ahead of mold. Growers familiar with Mk-Ultra or Sour Diesel will recognize much of its behavior. Whatever the listing says, the cut in YOUR tent is the ground truth: log feedings, readings, and photos, and let the trends — not the label — drive decisions.
UltraSour FAQ
How long does UltraSour take to flower?
UltraSour typically flowers in around 63 days after switching to a 12/12 light schedule. Individual phenotypes vary, so judge harvest readiness by trichome color, not the calendar.
Is UltraSour an indica or a sativa?
UltraSour is listed as mostly indica.
What are the parents of UltraSour?
UltraSour was bred from Mk-Ultra × Sour Diesel by TH Seeds.
What environment does UltraSour like?
Standard cannabis bands work well: VPD 0.8–1.1 kPa in veg and 1.0–1.4 kPa in flower, with humidity stepping down from 65–75% as a seedling to 40–50% in late flower. See the stage-by-stage table on this page.
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