Arjan's Ultra Haze #2 by Green House Seeds: A Comprehensive Strain Guide

Introduction and Overview

Arjan's Ultra Haze #2 is a long-flowering, sativa-leaning cultivar bred by Green House Seeds, the Amsterdam house synonymous with Haze-forward genetics. It was conceived to showcase soaring, cerebral clarity coupled with classic incense-citrus aromatics that define old-world sativas. This variety is not a quick finisher, but it compensates with impressive canopy vigor and a nuanced, layered flavor.

According to breeder-sourced data shared via CannaConnection, Arjan's Ultra Haze #2 typically tests between 17% and 22% THC. Flowering indoors usually takes 12 to 16 weeks, putting it firmly in the equatorial-sativa category. Patient growers are rewarded with yields reported up to 800 grams per square meter under optimized conditions.

The strain’s profile is shaped by the Haze lineage that underpins Green House Seeds' catalog, favoring tall architecture, airy colas, and unmistakable incense notes. It shines in SCROG canopies, high-ceiling tents, and greenhouses that can accommodate its stretch. For those who prefer bright, creative daytime effects and complex terpenes, Ultra Haze #2 delivers a distinct experience.

History and Breeding Origins

Arjan's Ultra Haze #2 emerged from the early-to-mid 2000s Amsterdam breeding scene, where Haze cultivars defined contests and coffeeshop menus. Green House Seeds, helmed by Arjan Roskam, worked Haze family lines into multiple expressions tailored for different environments and palates. The Ultra Haze series developed as a refinement of Haze vigor with more predictable architecture and resin production.

While the exact recipe remains proprietary, the Ultra Haze concept descends from the legendary Haze pool pioneered in California before being refined in the Netherlands. Influences likely include classic Haze and Haze-derived titans that Green House helped popularize globally. The goal was a sativa that sustains long, clear-headed effects without sacrificing modern resin density and terpene output.

Culturally, Ultra Haze #2 represents the bridge between heritage equatorial sativas and contemporary cultivation practices. Growers wanted the uplifting, motivational qualities associated with Southeast Asian lines, paired with yield and adaptability. The result is a plant that retains the mystique of incense-forward Hazes while fitting into controlled indoor production frameworks.

Genetic Lineage and Heritage

The genetic backbone of Arjan's Ultra Haze #2 is firmly sativa, as indicated by its growth habit and extended bloom time. Breeders at Green House Seeds have long utilized Haze derivatives, including well-known Dutch refinements, to build complex multi-parent hybrids. In the case of Ultra Haze #2, that likely includes a blend of Haze family stock and Southeast Asian influences.

In practice, the phenotype expresses hallmark Haze architecture: pronounced internodal spacing, rapid vertical growth during the first four to five weeks of flowering, and speared colas. Calyx development and stacking tend to accelerate later in bloom, a trait many Haze keepers know as the late swell. This aligns with sativa-dominant genetics, where biomass shifts from leaf to calyx later than in fast indica lines.

The heritage also implies a terpene fingerprint rich in terpinolene, pinene, and citrus-wood aromatics. Sativa-leaning polyhybrids with Southeast Asian ancestry often express sweet basil, lemongrass, and herbal notes in addition to incense. Ultra Haze #2 reflects these traits, fitting within the Haze class while maintaining a distinctive, modern profile.

Given how Hazes cross-pollinated between California, Mexico, South India, and Thailand before landing in Dutch breeding projects, Ultra Haze #2 can be seen as a globalized sativa. Its lineage embodies decades of selection for clear-headed effects and elegant aromatics. That history explains both the long maturation and the complex terpene structure.

Morphology and Appearance

Arjan's Ultra Haze #2 grows tall and lanky in early vegetative stages, with fine serrated leaflets and a high node count. Indoors, plants can reach 120 to 180 centimeters if untrained, and will easily exceed two meters outdoors in warm, sunny climates. The stretch in early flower can be 2x to 3x, making trellising and early topping valuable.

The inflorescences are long, tapering, and initially appear wispy compared to dense indica buds. As weeks progress, calyxes stack and swell, creating elegant spears with high calyx-to-leaf ratios. Trichome coverage becomes apparent by mid-flower and turns frosty white by the final swell.

Coloration ranges from lime to medium forest green, with occasional lavender tinges under cooler nights late in bloom. Pistils start cream to pastel orange, maturing to richer amber near harvest. Well-finished samples exhibit a shimmering, resin-laden surface and sticky, delicate bracts that grind into voluminous, fragrant material.

Aroma and Terpene Bouquet

The first impression is classic Haze incense, a cathedral-like note of wood, spice, and soft floral that reads sophisticated rather than sweet. Secondary layers bring citrus zest and lemongrass, often trailing a fresh-herb quality reminiscent of basil or Thai lime leaf. Many growers also note a cedar plank undertone and light peppery dryness in the nose.

When flowers are broken apart, the bouquet intensifies with terpinolene’s brisk, almost effervescent pine-citrus signature. Pinene-like freshness can cut through the top notes, while a faint wintergreen impression sometimes peeks out when the cure preserves monoterpenes. Once jarred, the aroma tends to sharpen and then deepen over 3 to 6 weeks as sesquiterpenes equilibrate.

Terpene expression in Haze-dominant cultivars is sensitive to drying and curing temperatures. Lower and slower dry curves preserve monoterpenes that give Ultra Haze #2 its bright, high-tone citrus and incense. Overly warm or fast dries flatten this profile, skewing toward generic herbal notes and muting its defining complexity.

Flavor Profile and Smoke Quality

On inhalation, expect bright citrus zest laced with sandalwood and clean pine. The flavor lands crisp rather than oily, with a lift that echoes the terpinolene-forward nose. The incense character is rounded and elegant, without the heavy sweetness that marks dessert hybrids.

As it lingers, a peppery-citrus snap and cedarwood dryness develop on the palate. Vaporizing at moderate temperatures preserves a clearer lemon-lime, herbal tone with less pepper. Combustion adds toastier wood and spice, slightly increasing perceived warmth and throat hit.

The finish is clean and persistent, leaving a cool, pine-herb aftertaste that encourages repeated sips rather than heavy pulls. Well-cured flowers deliver a smoother ride with fewer harsh edges and better preservation of high notes. Many enthusiasts prefer a 4 to 6 week cure for optimal finesse.

Cannabinoid Profile and Potency

Breeder data shared via CannaConnection lists Arjan's Ultra Haze #2 at approximately 17% to 22% THC under standard indoor conditions. This places it in the strong but not extreme category, with intensity shaped by both THC concentration and a lively terpene ensemble. The perceived potency is often enhanced by energetic terpenes that subjectively feel brighter.

CBD content in Haze-dominant cultivars is typically low, often at or below 0.5% in modern seedlines. Trace minors such as CBG commonly appear in the 0.2% to 1.0% window, depending on harvest timing and environmental conditions. THCV may appear in small amounts in some sativas, though its presence is variable and usually below 0.5% without targeted breeding.

For most consumers, onset after inhalation arrives within 3 to 10 minutes, peaks by 30 to 45 minutes, and tapers over 2 to 4 hours. The stimulating tilt can feel stronger than the raw number suggests, especially on an empty stomach or with minimal tolerance. First-time tasters should start with conservative doses and wait a full 15 to 20 minutes before re-dosing.

Decarboxylation and storage conditions meaningfully influence potency and flavor. Prolonged exposure to heat and light will degrade THC into CBN over time, dulling the energizing edge. Airtight, UV-protective storage at cool temperatures best preserves the profile over months.

Terpene Profile: Chemistry and Percentages

While exact lab percentages vary by phenotype and grow, Ultra Haze #2 routinely expresses a terpinolene-forward profile with supporting pinene, myrcene, and ocimene. In Haze-dominant sativas, total terpene content often falls between 1.5% and 3.0% by weight under careful cultivation. Within that total, terpinolene commonly anchors the bouquet in the 0.3% to 0.8% range.

Alpha- and beta-pinene together often contribute 0.2% to 0.6%, reinforcing pine, herbs, and a perceived mental clarity. Myrcene, while often dominant in modern hybrids, may sit in a supportive role here around 0.1% to 0.4%, adding pliancy and body to the aroma. Ocimene can appear from trace to 0.3%, lending green, floral, and tropical hints.

Caryophyllene and humulene bring a peppery, woody counterpoint in the 0.1% to 0.3% ranges each. Limonene, though not necessarily dominant, may land between 0.1% and 0.4%, brightening the citrus edge and enhancing perceived uplift. Minor contributions from linalool, nerolidol, and farnesene are occasionally detectable and can influence smoothness.

These ranges reflect common outcomes in Haze-style cultivars rather than a single fixed fingerprint. Environment, nutrition, harvest maturity, and post-harvest handling significantly alter terpene output. Cooler late-flower nights and disciplined low-temperature drying protect the monoterpenes that give Ultra Haze #2 its sparkle.

Experiential Effects and Use Cases

Arjan's Ultra Haze #2 is widely experienced as an energizing, clear-headed sativa with a focus on mental engagement. The early phase is characterized by alertness, focus, and an uplifted mood that can facilitate creative projects or conversation. The body feel is lighter than dense indica hybrids, with minimal heaviness when dosed conservatively.

As the session progresses, many report enhanced sensory detail and flow-state tendencies for tasks like writing, design, or music selection. The cultivar’s terpinolene and pinene pairing can feel brisk and refreshing, offering a clean headspace rather than dreamy introspection. That distinction makes it well suited for daytime use when motivation and clarity are priorities.

Typical physiological responses to THC include a transient increase in heart rate and dry mouth, which are common across cannabis experiences. Individuals sensitive to stimulating profiles may find the early phase racy if dosage is too high. A measured approach, hydration, and a calm setting help keep the arc smooth and productive.

Duration after inhalation often extends 2 to 3 hours in total, with a gentle comedown that leaves many users feeling buoyant. Those seeking a neutral-to-uplifting sativa that avoids couchlock tend to appreciate Ultra Haze #2’s balance. As with all sativa-leaning strains, mood, sleep, and caffeine intake can shape the experience.

Potential Medical Applications

While cannabis responses are individual and context dependent, the profile of Arjan's Ultra Haze #2 aligns with daytime-forward wellness goals. Anecdotally, users seeking mood elevation, motivation, or relief from fatigue lean toward sativa-leaning chemotypes. The limonene and pinene support an alert mental frame that some find compatible with task-oriented activities.

The National Academies 2017 synthesis concluded substantial evidence for cannabinoid-based therapies in chemotherapy-induced nausea and vomiting, and moderate evidence for chronic pain. These findings pertain to cannabinoids broadly rather than this specific cultivar, but they inform how THC-rich plants may be applied. For mood and anxiety, evidence is mixed and highly dose dependent, with stimulating chemovars sometimes counterproductive at higher doses.

Consumers also report using sativa-dominant profiles to break inertia in low-motivation states, incorporating microdoses alongside exercise or creative routines. Where legal, vaporization allows fine-tuned dose control to test whether small, sub-intoxicating inhalations improve function without overstimulation. Those with sensitivity to racy effects often fare better with very small doses and balanced CBD support.

Medical use should always be discussed with a clinician, especially if one has cardiovascular concerns or is taking medications that interact with cannabinoids. The stimulating onset of Ultra Haze #2 can increase heart rate temporarily, which some patients prefer to avoid. Careful titration and symptom tracking can help determine personal suitability.

Cultivation Guide: From Seed to Harvest

Only cultivate cannabis in jurisdictions where it is legal to do so, and follow all applicable laws and regulations. Arjan's Ultra Haze #2 is a sativa-leaning plant that requires more patience and vertical management than fast indica hybrids. Growers who plan ahead for a longer bloom and substantial stretch are rewarded with an elegant canopy and high terpene expression.

Germinate seeds in a stable, warm environment around 24 to 26 degrees Celsius with moderate humidity in the 60% range. Transplant seedlings once roots establish a fine web, avoiding overwatering during this delicate stage. Early vegetative growth benefits from gentle airflow and moderate light intensity to prevent stretching before training.

In vegetative growth, target day temperatures of 24 to 28 degrees Celsius and relative humidity around 55% to 65%, maintaining a VPD near 0.8 to 1.2 kilopascals. Light schedules of 18 hours on and 6 hours off are standard, with photosynthetic photon flux densities in the 400 to 600 micromoles per square meter per second range. Canopy management via topping, low-stress training, or mainlining helps establish an even horizontal frame for SCROG.

Transition to flower requires assertive training since stretch can reach 2x to 3x. Switch to 12 hours light and 12 hours dark and lower humidity to 45% to 55% in early bloom. Maintain day temperatures of 22 to 26 degrees Celsius and raise PPFD to 700 to 900 micromoles per square meter per second for robust flowering.

Nutrition should be balanced, with an emphasis on calcium, magnesium, and micronutrient stability. In soilless systems, keep solution pH near 5.8 to 6.2 during vegetative and 6.0 to 6.3 during flowering, adjusting EC from roughly 1.4 to 1.8 mS/cm early to 1.8 to 2.2 mS/cm mid-bloom if plants are hungry. Sativas can be sensitive to excess nitrogen late in flower, so taper N and favor phosphorus, potassium, and sulfur to support terpene and calyx development.

By mid-flower, lower humidity into the 40% to 50% range and protect airflow to prevent botrytis in the long, airy colas. Remove large interior fan leaves that shade key sites, but avoid over-defoliation that stresses sativas. Late in bloom, some growers drop night temperatures slightly to enhance color and preserve monoterpenes.

Arjan's Ultra Haze #2 typically requires 12 to 16 weeks in flower, as Green House Seeds notes via CannaConnection. Monitor trichomes with magnification in the final two weeks, looking for a shift from clear to mostly cloudy with a small fraction turning amber. Many Haze enthusiasts prefer harvesting with minimal amber to emphasize clarity over sedation.

Integrated pest management is essential over the long lifecycle. Maintain cleanliness, inspect undersides of leaves weekly, and rotate preventative measures appropriate to your legal context and cultivation style. Good canopy hygiene and a stable environment prevent most issues before they start.

Yield, Flowering Time, and Performance Metrics

Ultra Haze #2 is built for generous output when given time and space. The breeder-linked figure of up to 800 grams per square meter is attainable under optimized indoor conditions