Arjan's Ultra Haze 1

Arjan's Ultra Haze 1 Feminised Cannabis Seeds

Arjan's Ultra Haze 1 is a sativa-dominant feminised cannabis seed bred by Greenhouse Seeds from a three-way cross of Neville's Haze, Cambodian and Laos genetics. She won 1st Place at the High Times Cannabis Cup 2006, and the lineage reads like a passport stamped across Southeast Asia and the Dutch old school. This is a strain built for headspace — the kind of cerebral, reflective effect that makes you stare at a wall for twenty minutes and come away feeling like you've sorted something out. But she asks for patience in return: 13 to 14 weeks of flowering before you get to find out what the fuss is about.

Specifications for Arjan's Ultra Haze 1

Why Grow Arjan's Ultra Haze 1 Seeds

We've carried Greenhouse Seeds since the early days, and Arjan's Ultra Haze 1 is one of those strains that keeps showing up in conversations about proper sativa genetics. The reason is simple: the effect. At 16% THC, the number looks modest on paper — especially next to the 25%+ figures you see plastered everywhere now. But this strain isn't about brute force. The combination of 16% THC with approximately 0.2% CBD and roughly 0.5% CBN — a minor cannabinoid associated with the aged, oxidised side of the plant's chemistry — produces an effect that's described as extremely cerebral. Think contemplative, introspective, meditative. The kind of headspace people actually seek out rather than stumble into.

According to research published in Secondary Terpenes in Cannabis sativa L. (PMC, 2022), terpenes found in Haze and Arjan's Ultra Haze varieties suggest anti-inflammatory, antioxidant and antimicrobial properties (PMC9775512). That's the terpene profile doing work alongside the cannabinoids — not a magic bullet, but a layer of complexity that single-compound extracts can't replicate.

The honest limitation? Time. At 13 to 14 weeks of flowering, she takes nearly double what most indica-dominant hybrids need. That's 3+ months of electricity, nutrients and attention before you see a single ripe trichome. If you're used to 8-week strains, this will test your patience. But the yields — 600 to 700g/m² indoors, potentially over 1kg outdoors in a warm climate — make the wait worthwhile if you can commit.

Growing Arjan's Ultra Haze 1: What to Expect

She's a tall plant. That's not marketing speak — Arjan's Ultra Haze 1 will stretch aggressively, especially in the first few weeks of flower. The long branches and sativa structure mean you need vertical space or a solid training plan. Compared to something like Greenhouse Seeds' Hawaiian Snow (another sativa-leaning strain in their catalogue), Ultra Haze 1 is similarly lanky but tends to produce denser, more rocket-shaped flower clusters.

The buds themselves have a distinctive look: large, elongated colas covered in nearly white pistils with just a scattering of orange hairs. It's a visual that stands out in any garden — almost silver under the right light. The aroma leans hazy and complex, with that unmistakable Neville's Haze backbone coming through alongside the Southeast Asian landrace influence from the Cambodian and Laos parents.

One thing we'd flag: she needs support as harvest approaches. Those long branches get heavy with bud, and without ties or a trellis net, you'll end up with snapped limbs. This isn't a set-and-forget strain. She rewards attentive growers who enjoy the process.

How to Grow Arjan's Ultra Haze 1 Feminised Seeds

1. Germinate your feminised seeds using the paper towel method or directly in a starter plug. Taproot should emerge within 24-72 hours.
2. Transplant seedlings into their final containers early — sativas don't love root disturbance mid-grow. A 15-20 litre pot works well indoors.
3. Keep the vegetative period short (3-4 weeks) if growing indoors. She'll double or triple in height during the flowering stretch, so flip to 12/12 before she outgrows your space.
4. Apply LST (Low Stress Training) from early veg. Bend and tie the main stem to open up the canopy. This strain responds brilliantly to LST, and it's the best way to manage her height while boosting light distribution to lower bud sites.
5. Switch to flowering nutrients when you flip the light cycle. She'll be in flower for 13-14 weeks, so pace your feeding schedule accordingly — don't push too hard too early.
6. Install a trellis net or use individual plant ties from week 6-7 of flower onwards. The branches will need physical support as the rocket-shaped colas pack on weight.
7. Begin flushing 10-14 days before harvest. Check trichomes with a loupe — you're looking for mostly cloudy with minimal amber for that cerebral, heady effect.
8. Harvest, dry slowly in a dark room at 18-20°C and 55-60% humidity for 10-14 days, then cure in glass jars for at least 2-3 weeks. Patience on the cure pays off just as much as patience during flowering.

Indoor vs Outdoor: Arjan's Ultra Haze 1 Yields

Indoors, expect 600 to 700g/m² under proper lighting with LST applied. That's a serious return for a sativa — most pure haze strains struggle to hit those numbers without training. The trick is canopy management: keep her flat, keep her fed, and give her the full 13-14 weeks she needs.

Outdoors, she can exceed 1kg per plant, but there's a catch. She needs a warm climate — think southern Spain, southern Italy, or a greenhouse in the Netherlands. She won't be ready for harvest before early November, which rules out most of northern Europe for outdoor growing unless you've got a polytunnel or heated greenhouse. If you're in a cooler climate and want a sativa from Greenhouse Seeds, you might have better luck with a faster-finishing option.