K.C.42 Regular Seeds by KC Brains Holland – Hazy Sativa Hybrid for High Yields

K.C.42 Regular Seeds by KC Brains Holland represent a classic sativa-dominant powerhouse, bred for growers who chase towering plants, colossal yields, and a clear-headed, energetic high. This strain is your ticket to cultivating a piece of legendary Haze heritage with modern resilience.

Frustrated with sativas that stretch out of control or take forever to finish?

You love that soaring, creative sativa buzz, but dealing with plants that hit the ceiling of your tent or flower for what feels like an eternity can be a real buzzkill. The long wait, the constant height management, the risk of mould in those dense, slow-forming buds… it can turn the joy of growing into a chore.

Imagine the disappointment after months of care, only to harvest airy buds or lose your crop to rot.

That time and energy investment deserves a payoff, not a letdown. A sativa that doesn't perform is more than just a failed grow; it's a missed opportunity for the kind of uplifting, cerebral experience that makes all the effort worthwhile.

K.C.42 is your solution: a manageable, high-yielding sativa hybrid built for success.

KC Brains has expertly blended the best of New Zealand genetics with a robust KC 639 male, creating a sativa-dominant plant that retains the legendary Haze character but with improved structure and faster flowering times indoors. This is the sativa you can actually tame and enjoy.

What K.C.42 delivers for your garden

This isn't just another Haze cross. K.C.42 is engineered for the grower who wants impressive results without the usual sativa headaches. It brings the signature sativa effects in a more cooperative package.

• Massive Yield Potential: Unlock outdoor harvests of up to 1.3 kg (2.87 lb) per plant or a solid 150 g (5.29 oz) per plant indoors, rewarding your space and effort.
• Controlled Indoor Height: Reaches a manageable 170 cm (5.58 ft) indoors, responding well to training like SCROG to maximize light penetration and bud sites.
• Potent, Uplifting Effect: With THC levels reported around 20-22%, expect a powerful, energetic, and euphoric cerebral high perfect for daytime creativity.
• Robust Genetics: Inherits a strong resistance to common moulds and pests, and shows good tolerance to variations in watering, making it more forgiving than finicky pure sativas.
• Distinctive Aroma & Flavor: The journey begins with fresh citrus during flowering, maturing into sugary, aromatic buds with a classic hashish aftertaste that seasoned connoisseurs will love.

How to grow K.C.42 for epic results

To get the most from these genetics, a tailored approach works best. Here’s a concise guide.

Start smart for vigorous beginnings.

• Germinate in a warm, humid environment (22-25°C / 71-77°F).
• Use an airy, well-draining substrate to encourage strong early root development.
• Transplant to its final pot early to avoid stunting; a 15-20 L (3.96-5.28 gal) pot is ideal for indoor photoperiods.

Manage the stretch during vegetative growth.

• Indoors, utilize the 18/6 light cycle to build a strong structure. This strain benefits from Low-Stress Training (LST) to create an even canopy.
• Outdoors, ensure plenty of space as it can reach 2-2.5 m (6.56-8.20 ft). A sunny, Mediterranean-like climate is perfect.
• Maintain a pH of 6.0-6.5 in soil, and keep humidity around 60-70% during early veg.

Navigate the flowering phase for dense buds.

• Indoor flowering takes approximately 9-12 weeks. Switch to a 12/12 light cycle to trigger blooming.
• Reduce humidity to 40-50% in late flower to protect the dense, chunky buds from botrytis.
• Support heavy branches in the final weeks. A boost of phosphorus and potassium during peak flowering can enhance bud density and resin production.

Harvest and cure to perfection.

• Outdoor harvest in the Northern Hemisphere is typically around the end of October.
• Harvest when trichomes are mostly milky with some amber for a balanced effect. A proper dry (18-22°C / 64-72°F, 50-60% RH for 10-14 days) and cure (2-4 weeks in jars) will refine the complex citrus and hash flavors.

Frequently Asked Questions

Is K.C.42 suitable for beginner growers?

While its resilience is good, its sativa dominance and longer flowering time present a medium difficulty level. Beginners can succeed with careful attention to training and climate control, but it's ideal for growers with some experience.

How does the effect of K.C.42 feel?

Users report a strongly cerebral, energetic, and euphoric high characteristic of sativa-dominant strains. It's ideal for daytime use, enhancing creativity and social activities without heavy sedation.

What's the main difference between growing it indoors vs outdoors?

Indoors, you'll need to manage its height through training and have patience for the 9-12 week flower. Outdoors, it becomes a true giant, requiring space and a long growing season but rewarding you with potentially massive yields.

How pungent is it during growth?

The aroma is pronounced, especially late in flowering. A carbon filter is highly recommended for indoor discreetness, as the sweet citrus and hash notes can be quite strong.

Technical specifications

• Breeder/Brand: KC Brains Holland
• Type: Regular Seeds
• Dominance: Mostly Sativa
• Genetics: New Zealand Sativa x KC 639
• Indoor Flowering: 9-12 weeks
• Outdoor Harvest (N. Hemisphere): End of October
• Indoor Yield: Approx. 150 g/plant (5.29 oz/plant)
• Outdoor Yield: Up to 1300 g/plant (2.87 lb/plant)
• Indoor Height: Approx. 170 cm (5.58 ft)
• Outdoor Height: 2 - 2.5 m (6.56 - 8.20 ft)
• THC: Approx. 20-22%
• CBD: Low
• Aromatic Profile: Sweet citrus, hashish

Personal Experience of Pevgrow’s CEO (Alan)

I've always been drawn to classic sativa effects, but as a grower with limited space, the legendary stretch was a deal-breaker. K.C.42 changed that for me. I ran her indoors in a 1.2x1.2m (3.94x3.94 ft) tent under a full-spectrum LED. The key was an early topping and then employing a SCROG net—she took to training beautifully, creating an even canopy that maximized every watt of light.

The smell during the final weeks was incredible; a sharp, sweet citrus that filled the room, unmistakably Haze. The buds stacked densely on the branches, much more so than I expected from a sativa-leaning plant. After a 70-day flower, the harvest was substantial. The smoke? Exactly what I was after: a clean, energetic lift that sharpens the mind without any anxiety. It's become my go-to for weekend projects when I need focus and a smile. For anyone wanting that traditional sativa experience without the 14-week flower time, K.C.42 is a brilliant choice.