Zwarte Jan by Old Dutch Genetics
A indica-leaning cross of Jack Herer × Black Domina, Zwarte Jan — released by Old Dutch Genetics — shows up in a lot of tents for good reason. Indoors it typically finishes flowering in around 67 days after the flip to 12/12. The environment targets below are the same stage-by-stage bands the Cultivar journal grades real Zwarte Jan grows against.
🌿 Start a Zwarte Jan journal — free →
Similar strains
| Breeder | Old Dutch Genetics |
|---|---|
| Type | mostly indica |
| Flowering time | ±67 days |
| Environment | Outdoors |
| Lineage | Jack Herer × Black Domina |
| Descendants | Black Betty |
🌱 Get Zwarte Jan seeds →
Affiliate link — supports Cultivar at no cost to you.
🧬 Explore the family: Jack Herer · Black Domina · Black Betty
Ancestry Pedigree
Sensi Seeds
The Seed Bank
Clone Only Strains
Unknown or Legendary
Original Strains
Original Strains
Sensi Seeds
The Seed Bank
Cultivators Choice
Original Strains
Original Strains
Sensi Seeds
Original Strains
Unknown or Legendary
Original Strains
Sensi Seeds
The Seed Bank
Clone Only Strains
Unknown or Legendary
The Seed Bank
Clone Only Strains
Unknown or Legendary
The Seed Bank
Sensi Seeds
The Seed Bank
Unknown or Legendary
Original Strains
Unknown or Legendary
Growing Zwarte Jan: 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 Jack Herer or Black Domina 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.
Zwarte Jan FAQ
How long does Zwarte Jan take to flower?
Zwarte Jan typically flowers in around 67 days after switching to a 12/12 light schedule. Individual phenotypes vary, so judge harvest readiness by trichome color, not the calendar.
Is Zwarte Jan an indica or a sativa?
Zwarte Jan is listed as mostly indica.
What are the parents of Zwarte Jan?
Zwarte Jan was bred from Jack Herer × Black Domina by Old Dutch Genetics.
What environment does Zwarte Jan 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.
📷 Growing Zwarte Jan and something looks off? Free AI photo diagnosis →
Facts compiled from public breeder listings. Growing Zwarte Jan? A structured journal — with your feedings, readings, and photos — is how you find what THIS cut actually wants.
Track your own grow free — the journal grades your environment against these bands →
Get the one-page grow reference card
VPD, pH by medium, deficiency symptoms and dry/cure targets on a single printable page. Free — plus the occasional grow-data breakdown. No spam, unsubscribe in one click.