M-39 cannabis seeds packaging — Royal King Seeds the UK
Hybrid
THC 16%
🎨 Creative
HybridFeminizedIn Stock

M-39 Feminized

Feminized PhotoperiodSee Lab Report →

M-39 Feminized — hybrid cannabis seeds suited to UK growing conditions. 16% THC with creative, happy, talkative effects. Fast, discreet UK delivery.

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About M-39 Feminized

Here is what M-39 delivers at harvest: 350-450 gr per square metre indoors, 500 gr per plant outdoors in UK conditions, with resin production peaking at 16% THC. Those numbers tell a story when you work backwards through the 39-43 days window. Weight distribution across the 39-43 days cycle is pleasingly even, with a noticeable surge in the closing two weeks that rewards growers who resist harvesting prematurely. The 60/40 balance means you get both calyx stacking density and respectable trichome spread. For outdoor UK customers, the ideal harvest window lands between late September and mid-October — early enough to dodge the wet autumn finish in most regions, late enough to capture the full caryophyllene terpene development.

Maximising Your Harvest

To reach the upper end of this strain's yield potential (350-450 gr indoors, 500 gr outdoors), focus your efforts on three critical windows during the 39-43 days period.

Window 1: The first 10 days after flowering begins. Stretch management determines canopy uniformity, which directly impacts light distribution and final yield. Moderate 30-40% stretch is typical. One round of low-stress training on the tallest shoots keeps everything level.

Window 2: Weeks 3-5 of bloom. Caryophyllene terpene biosynthesis ramps up during this period. Maintain a day/night temperature differential of at least 6-8°C to encourage terpene accumulation — UK autumn evenings (September-October) naturally provide this swing for outdoor growers. Indoor cultivators should target 25-26°C during lights-on and 18-20°C during lights-off. Supplement with potassium-heavy bloom nutrients at EC 1.6-1.8.

Window 3: Final 10-14 days before harvest. Cease all nutrient input and flush with pH-adjusted water. Monitor trichomes daily with a 60x jeweller's loupe — harvest at 10-15% amber for a balanced effect. UK outdoor growers: this window typically falls from late September through mid-October.

Flowering: 39-43 days. Indoor yield: 350-450 gr. Outdoor yield: 500 gr. Rated intermediate difficulty.

What to Expect When Using M-39

UK customers report creative, happy, talkative as the defining characteristics, and our experience aligns with that consensus. At 16% THC, this hybrid sits in a potency bracket where versatility is the main advantage. Morning users report functional clarity at lower doses. Evening users report satisfying relaxation at higher doses. The ${indica}/${sativa} balance means the dominant effect direction shifts with consumption amount rather than being locked into a single character. The Caryophyllene/Myrcene terpene combination imparts a flavour that lingers on the palate — warm and spiced, drying slightly on the exhale.

Ideal settings: adaptable across occasions — adjust dose to match the energy level your situation calls for.

Terpene Breakdown

Primary: Caryophyllene · Secondary: Myrcene · Tertiary: Humulene. Flavour translation from flower to vapour and smoke differs with this terpene combination. Low-temperature vaporisation (180-188°C) highlights the myrcene and humulene notes whilst keeping caryophyllene as a foundation. Higher temperatures or combustion flatten the profile into a single-note experience — still pleasant, but lacking the complexity that makes this cultivar genuinely interesting to those who appreciate flavour.

Suitability and Recommendations

M-39 suits growers with fundamental skills already established. You should understand pH management, basic nutrient ratios, and light cycle requirements before committing to this cultivar — it will not hold your hand, but it will not punish minor mistakes harshly either. Photoperiod genetics give you complete control over plant size and harvest timing — extend the vegetative phase for larger plants or flip early for a quicker turnaround in compact spaces. The UK growing season (April through October) accommodates the 39-43 days bloom period comfortably for outdoor cultivators across the country. Shipped discreetly across the UK with our germination guarantee.

Effects

🤩Creative
77% of people reported feeling Creative
😊Happy
65% of people reported feeling Happy
🗣️Talkative
57% of people reported feeling Talkative
😌Relaxed
51% of people reported feeling Relaxed
🤗Euphoric
47% of people reported feeling Euphoric
😎Uplifted
38% of people reported feeling Uplifted
🤤Hungry
34% of people reported feeling Hungry
😴Sleepy
31% of people reported feeling Sleepy
😆Giggly
24% of people reported feeling Giggly

Strain Type

Indica 60%Sativa 40%

Strain Data Sheet

🧬THC16% - 19% (Medium-High)
🌿LineageNorthern Lights No. 5 × Skunk No. 1
🔬TypeFeminized Hybrid
🌡ClimateTemperate, adaptable
📅HarvestLate Sept – Oct, UK outdoor (typical)
📏Height100 – 160 cm (typical)
⚖️YieldTypical for type
🏠Yield Indoor350-450 gr
🌳Yield Outdoor500 gr
Flowering Time39-43 days

Packaging

Resealable +
RK
Royal King Seeds
Photoperiod
Feminized Premium
Seeds
Premium Genetics
Protective vial
Resealable +
Royal King Seeds supplies seeds as adult novelty collectibles and for genetic preservation. Purchasers must comply with all applicable UK Commonwealth, state, and territory legislation.
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M-39 Feminized
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💧Waterproof coating
🛡️Aluminium interior lining
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🔢Scratchable serial number

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M-39 Feminized — Breeder Information

Royal King Genetics

Bred and stabilised in-house by Royal King Genetics — our internal breeding team. Every batch is QC'd and germ-tested above 99% before it ships. Read the full breeding process and about page.

Stabilisation Level
BX2
Generations
3+
Breeding Programme
Royal King Genetics Backcross Line — BX2 modern hybrid stabilisation
Stabilisation Notes — What This Means for Your Grow

M-39 carries clone-derived parents from the modern hybrid. We backcrossed twice to the dominant parent (BX2) to weld cut-specific traits into seed-stable form. Vigour and finish-time consistency run uniform across the population.

Breeding Goal

Stabilise the M-39 cross into a seed-uniform line.

Selection Focus

Chosen for trichome density, bud structure and the hybrid trait balance the cross was engineered for.

Pollen / Mother Source

Royal King Genetics in-house breeder room — pollen taken from a generation-tracked sibling-male line.

Last Batch QC Verified
23 April 2026· 99%+ germination