K.C. 39 Regular Seeds by KC Brains Holland · High-Yield, Citrus-Hash Indica Hybrid

The K.C. 39 Regular seeds from KC Brains Holland are your ticket to cultivating one of the most generous and robust indica hybrids available, a strain forged from a legendary Spanish lineage and bred for unstoppable performance.

Ever feel like you're putting in all the effort for a harvest that just doesn't match the hype? You water, you feed, you wait... only to end up with a modest yield that's gone in a flash. It's frustrating, watching your time and care translate into less bud than you dreamed of. That disappointment hits harder when you're limited on space or battling unpredictable outdoor elements, leaving you wondering if a truly heavy harvest is just a myth for the average grower.

K.C. 39 shatters that myth. This isn't a finicky, low-yield novelty; it's a workhorse genetics designed to pump out serious weight. Whether you're working with a tight indoor tent or a sunny backyard patch, this strain is engineered to maximize your return on every gram of effort. It's the solution for the grower who's tired of small returns and ready for a harvest that actually fills jars.

Mastering Your Indoor Garden

Indoors, K.C. 39 is a space-efficient champion. It stays a manageable 1.20 m (3.94 ft) tall, making it perfect for tents or cabinets. Its mostly indica structure means it grows bushy and stout, allowing you to train it effectively with techniques like LST (Low Stress Training) to create an even canopy and boost yields. Under optimal conditions, you can expect a hefty indoor yield of around 200 g (7.05 oz) per plant. Its 7-9 week flowering time means you're not waiting forever—you'll be trimming those dense, sticky colas in just over two months from flip.

Conquering the Great Outdoors

If you have the space and sun, K.C. 39 truly shines outdoors. This plant can stretch to an impressive 2–3 m (6.56–9.84 ft), transforming into a true tree. It's bred for resilience, showing excellent resistance to common pests and molds, which is a lifesaver in less-than-perfect climates. Plant it in the ground or a large pot with good soil, give it plenty of light, and prepare for a legendary harvest in early to mid-October, with potential yields soaring up to 1000 g (2.20 lb) per plant. That's the kind of yield that turns a season's work into a year's supply.

Choosing Your Grow Adventure

Whether K.C. 39 is your indoor secret weapon or your outdoor centerpiece depends on your goals and setup.

• For the discreet, controlled gardener: If you prioritize stealth, climate control, and multiple harvests per year, the indoor route is for you. Its compact height and predictable flowering are perfect for a structured grow space.
• For the sun-chasing maximizer: If you have a secure, sunny spot and dream of monster plants, take it outside. Just ensure you have support for those heavy branches come late flower!
• For the beginner: Its easy-going nature and pest resistance make it a fantastic first-time grow for either environment. Start with good-quality soil or a reliable substrate and watch it thrive.
• For the experienced cultivator: Use its vigorous growth and responsiveness to training to push yields even further. Experiment with topping or SCROG nets indoors to maximize your canopy.

Advantages and Benefits You Can't Ignore

Choosing K.C. 39 isn't just about picking a seed; it's about investing in a proven, high-performance experience.

• Monster Yielder: Consistently ranks among the highest-yielding strains, delivering up to 1000 g (2.20 lb) outdoors and 200 g (7.05 oz) indoors.
• Grower-Friendly Genetics: High resistance to pests and fungi means fewer headaches and a higher success rate, especially for beginners.
• Fast Flowering for an Indica: A relatively quick 7-9 week indoor flowering period gets you to harvest faster than many other heavy-yielding indicas.
• Potent, Relaxing Effect: With a reported THC content around 20%, it delivers a powerful, full-body stone perfect for unwinding after a long day.
• Unique Citrus-Hash Profile: The aroma evolves from a fresh, citrusy scent during growth to a deeper, hashy, fuel-like fragrance in the cured buds, offering a complex sensory experience.
• Versatile Growing Options: Performs exceptionally well in both indoor and outdoor setups, adapting to your available space and style.

Technical Specifications

• Breeder/Brand: KC Brains Holland
• Type: Regular Seeds
• Dominance: Mostly Indica
• Genetics/Cross: Potent Spanish Strain x KC 606
• Indoor Flowering Time: 7–9 weeks
• Outdoor Flowering Time: 8–11 weeks
• Outdoor Harvest: Mid-October (Northern Hemisphere)
• Indoor Yield: Approx. 200 g (7.05 oz) per plant
• Outdoor Yield: Approx. 1000 g (2.20 lb) per plant
• Indoor Height: Approx. 1.20 m (3.94 ft)
• Outdoor Height: 2–3 m (6.56–9.84 ft)
• Difficulty: Low (Easy for beginners)
• Resistance: High resistance to pests, fungi, and diseases
• Aromatic Profile: Citrus, hash, fuel
• Reported THC: Approx. 20%

How to Grow K.C. 39 Seeds Successfully

Quick Overview: A regular, mostly indica photoperiod strain from KC Brains. It's a low-difficulty, high-yield plant perfect for beginners and pros alike, thriving both indoors and in temperate outdoor climates.

Safe Start & Strong Roots: Germinate your seeds in a warm, humid environment. Once sprouted, focus on building a robust root system. A product like Tribac can help establish a healthy microbial base for stronger early growth.

• Use an airy, well-draining soil or coco mix.
• Keep seedlings under gentle light (18/6 cycle) with high humidity.
• Transplant to final pots before the flowering stretch.

Veg Growth & Training: This plant enjoys training. Utilize Low-Stress Training (LST) during vegetative growth to create an even canopy and maximize light exposure for more bud sites.

• Maintain an 18/6 light cycle during vegetative growth.
• Water when the top layer of soil is dry.
• It responds well to topping if you want to encourage more main colas.

Flowering & Fattening Buds: Switch lights to 12/12 to induce flowering. This is when K.C. 39 will stretch and start forming its dense, resinous colas.

• Reduce humidity gradually to 40-50% to prevent mold on the dense buds.
• Ensure excellent air circulation around the canopy.
• Support heavy branches in late flower to prevent breakage.

Harvest, Dry & Cure: Harvest when trichomes are mostly milky with some amber for a balanced, relaxing effect. A proper dry (10-14 days at 16-20°C, 50-60% RH) and cure (4+ weeks in jars) will reveal its full citrus-hash flavor and smooth smoke.

Frequently Asked Questions

Is K.C. 39 good for beginners?

Absolutely. Its high resistance to pests and diseases, combined with forgiving growth patterns, makes it an excellent choice for a first-time grower looking for a substantial yield.

How tall does K.C. 39 get outdoors?

It can become a true giant, reaching between 2–3 m (6.56–9.84 ft) tall under optimal sunny conditions. Make sure you have the vertical space and consider staking for support.

What does K.C. 39 smell and taste like?

During growth, it emits a sharp, citrusy aroma. As the buds mature and cure, this evolves into a deeper, classic hash and fuel-like scent, translating into a smooth smoke with earthy, hash-forward flavors.

How long does it take to flower indoors?

Indoors, K.C. 39 has a relatively fast flowering time for a high-yield indica, typically finishing in 7 to 9 weeks after switching the light cycle to 12/12.

Can I grow K.C. 39 in a small indoor tent?

Yes. While it can get large outdoors, indoors it typically stays around 1.20 m (3.94 ft). With techniques like LST and SCROG, you can manage its height and width effectively in a confined space.

Personal Experience of Pevgrow’s CEO (Alan)

I've run K.C. 39 both in a controlled indoor setup and in a sunny outdoor greenhouse, and it never fails to impress with its sheer output. Outdoors is where it truly becomes a spectacle—watching it tower over other plants is a joy. The smell is unmistakable; that sharp, almost lemony fuel scent in late flower lets you know you're in for something special. For me, the sweet spot is harvesting when the trichomes are about 70% milky and 30% amber. This gives a powerful, full-bodied stone that's perfect for late evenings, but it's not a couch-lock so heavy you can't function. My pro-tip? Don't be shy with support in the final weeks. Those colas get incredibly dense and heavy, and a few well-placed yo-yos or a soft trellis can save a major branch. It's a classic, no-nonsense strain from KC Brains that delivers exactly what it promises: massive yields of potent, flavorful bud without any drama during the grow.