Written by Ad OpsHistory and Origins of Granite Haze F4
Granite Haze F4 is a modern ruderalis/sativa hybrid developed by Speedrun Seeds, a breeder known for fast-cycling, resilient lines. The F4 designation means this selection has been refined through four filial generations to stabilize desired traits. In practical terms, the line carries most of its target characteristics consistently while still allowing a touch of variability for vigor and adaptation. Growers looking for a reliable, sativa-leaning autoflower gravitated toward this release as it matured into its F4 form.
The name Granite Haze suggests a union between classic Haze aromatic signatures and a sturdy, stone-solid growth frame. Unlike older photoperiod Hazes that often require 10–14 weeks of flowering, the ruderalis infusion allows a compressed lifecycle. This translates into more predictable turnarounds, often under 12 weeks from seed in controlled conditions. For cultivators seeking Haze-like clarity without the long wait, Granite Haze F4 offers a pragmatic middle path.
The strain emerged from a wave of breeder interest in terpene-rich autos that rival photoperiod potency. Over the last decade, average THC in autoflowers increased substantially, with commercial lab reports commonly showing 16–22% THC in modern autos versus sub-12% averages a decade earlier. Granite Haze F4 fits within this new class, targeting photoperiod-like potency alongside sativa-forward effects. Speedrun Seeds positioned it for both hobbyists and micro-producers wanting dependable turns without sacrificing character.
Given the limited public lab data specific to Granite Haze F4, most insights come from breeder notes, grower logs, and analogs from comparable Haze-leaning autos. These sources collectively describe a cultivar with a bright, terpinolene-forward bouquet and a tall, airy structure. As the F-line progressed, stability improved in plant height, internodal spacing, and terpene dominance. By F4, growers report fewer outliers and more uniform harvest windows.
Genetic Lineage and Breeding Rationale
Granite Haze F4 descends from a sativa-dominant Haze archetype crossed with a robust ruderalis donor to impart autoflowering and hardiness. Haze families often express terpinolene, pinene, and citrus-forward volatiles, which are preserved here with careful selection. The ruderalis backbone contributes photoperiod independence, allowing flowering based on age rather than day length. This hybridization is aimed at transplanting classic Haze character into a compact, faster package.
The F4 label reflects an advanced stage of filial selection. From a population genetics standpoint, heterozygosity typically halves each generation: roughly 50% at F2, 25% at F3, and 12.5% at F4. That implies about 87.5% of loci are homozygous on average by F4, so trait expression becomes more predictable. It is not a true-breeding line yet, but phenotype variance is markedly reduced compared to F2 or F3.
Speedrun Seeds likely prioritized three pillars across the generational work: fast finish, terpinolene-forward bouquet, and sativa-like vigor. In autos, these targets can conflict; for instance, sativa vigor tends to lengthen the lifecycle, while ruderalis shortens it. The breeder’s task is to balance earliness with adequate biomass and resin maturation. The F4 stage indicates a workable compromise in most environments, with fewer phenotypes running too long or finishing too airy.
Another design goal was adaptability to differing latitudes and indoor setups. Ruderalis ancestry confers tolerance to cooler nights and variable photoperiods, and Haze ancestry contributes high light-use efficiency. Together, this pairing can maintain productivity in 18/6 or 20/4 lighting without the photoperiod flip. As a result, Granite Haze F4 can be staged in perpetual harvests or outdoors for multiple runs per season in warm climates.
Appearance and Morphology
Granite Haze F4 typically presents as a medium-tall autoflower with a columnar main stem and multiple lateral spears. Indoors, plants average 70–120 cm in height with training, while untrained specimens may surpass 130 cm under high PPFD. Internodal spacing of 3–6 cm is common, producing an open, breathable canopy. Leaves skew narrow and serrated, aligning with sativa morphology.
Flower structure favors elongated, foxtail-resistant colas with a healthy calyx-to-leaf ratio. Buds tend to be lime to forest green, with occasional lavender hues under cooler night temperatures. Pistils begin cream or light peach and ripen to copper or rust with maturity. Trichome density is high, with capitate-stalked glandular heads dominating the resin layer.
Under magnification, trichome heads often sit in the 80–120 micron range, comparable to many high-terp sativas. The resin layer frequently extends onto sugar leaves, making trim hash or dry sift productive. Stems are firm, and lateral branches benefit from light support in late bloom. The overall silhouette suggests airflow resilience, a boon for humid environments.
Dried flowers cure into tapered, diamond-like spears with a slightly looser structure than indica-heavy autos. This structural openness helps retain volatile terpenes during drying if conditions are controlled. When properly manicured, cured buds exhibit a glistening frost and minimal leafy protrusions. The finished bag appeal leans classic Haze, with an elegant, elongated profile.
Aroma
Aroma leans bright and airy, with an unmistakable Haze signature overlaid on clean, mineral back-notes. The top notes often include sweet citrus, green apple skin, and pine, pointing to a terpinolene and pinene axis. Mid tones of fresh-cut herbs, white pepper, and balsamic spice surface as flowers mature. A subtle flinty or wet-stone impression justifies the Granite moniker.
Freshly broken buds release an energetic bouquet that fills a room within minutes. Many growers report that terp intensity spikes between day 45 and day 65 from seed as resin heads swell. During cure, the nose evolves from high-pitched citrus-pine to a more layered incense-herbal profile. A well-executed 4–8 week cure notably smooths the edges and deepens the spice register.
Haze-forward cultivars are frequently terpinolene-dominant, even though terpinolene dominance is uncommon across the broader market. Public datasets have shown terpinolene-dominant profiles constitute a minority of retail samples compared to myrcene, caryophyllene, or limonene dominance. Granite Haze F4 aims to sit in that rarer aromatic category, delivering a nose that consumers often describe as sparkling and lucid. The ruderalis influence does not blunt the bouquet when plants are grown under adequate light and nutrition.
Handling during harvest can either preserve or strip these volatiles. Cold, slow drying at around 60°F and 60% RH for 10–14 days maintains higher terpene retention than fast-dry methods. Avoiding rough trimming and excessive desiccation protects the top notes. Airtight storage at stable temperatures prevents the pine-citrus high notes from flattening over time.
Flavor
Granite Haze F4 tastes like classic Haze with a clean, mineral edge. The front palate is zesty and green, combining lemon-lime spritz with pine needles and fresh basil. Mid-palate brings white pepper, coriander, and faint floral sweetness. The finish lingers as dry citrus peel and polished cedar.
Combustion maintains much of the brightness if the cure is slow and thorough. Vaporization enhances nuance, especially at mid-range temperatures optimized for monoterpenes. Users often report a cool, sparkling mouthfeel that matches the granite theme. Resin does not tend to coat the palate heavily, keeping the experience crisp rather than syrupy.
Flavor stability depends on careful post-harvest handling. Rapid drying or high storage temperatures can mute the citrus and shift the profile toward generic herb. With proper jar burping and humidity buffers around 58–62%, flavors integrate for weeks. Many tasters find the spice-mineral thread becomes more obvious after week four of curing.
When paired with beverages, crisp flavors align well with seltzer, dry Riesling, or unsweetened green tea. Rich, sugary pairings can overshadow the delicate top notes. Savory foods with citrus and herbs complement the profile better than dessert-forward options. Terpene-driven strains like this reward clean palates and measured sips or puffs.
Cannabinoid Profile
As a ruderalis/sativa auto, Granite Haze F4 targets photoperiod-like potency with a fast cycle. Reported THC values in analogous Haze-forward autos commonly range between 16% and 24% by dry weight, depending on environment and cut. CBD is typically minimal, often 0.1–0.8%, with CBG in the 0.3–1.5% range. THCV may appear in trace amounts but is not a defining cannabinoid for this line.
Keep in mind that total THC on a certificate of analysis reflects both THC and its acidic precursor. The standard formula used by labs is Total THC = (THCA × 0.877) + THC. Harvest timing shifts these ratios; earlier cuts skew higher in THCA, while later cuts may show slightly higher measured THC after decarb. For inhalation, decarboxylation occurs quickly, so consumer-experienced potency tracks closely with total THC.
Bioavailability varies by route. Inhalation yields roughly 10–35% systemic bioavailability, with onset within 2–10 minutes and peak effects around 30–60 minutes. Oral routes produce lower bioavailability (often 4–12%) but longer duration, peaking at 1.5–3 hours. These pharmacokinetic realities mean perceived potency can exceed the raw number on a label when delivery is efficient.
Cannabinoid stability declines over long storage windows, especially with heat and oxygen exposure. Studies have reported 10–20% THC loss over 12 months at room temperature, with corresponding increases in CBN. Vacuum sealing, cool storage, and darkness slow this degradation significantly. For medical users depending on dosage precision, periodic re-testing or fresh batches are prudent.
Terpene Profile
Granite Haze F4 is expected to be terpinolene-forward, with alpha- and beta-pinene, limonene, and a supporting layer of beta-caryophyllene and ocimene. Total terpene content in dialed-in grows commonly falls in the 1.5–3.0% range by dry weight, though environment and cure can shift totals. A representative distribution might see terpinolene around 0.3–0.9%, pinenes at 0.2–0.6% combined, limonene at 0.2–0.5%, and caryophyllene at 0.2–0.4%. Minor contributors can include humulene, linalool, and nerolidol in the 0.02–0.15% range each.
Terpinolene correlates with bright, effervescent aromas and is common in Haze archetypes. Alpha- and beta-pinene contribute conifer notes and have been studied for potential alertness-promoting and bronchodilatory effects. Limonene underpins citrus notes and has shown mood-elevating associations in observational data. Beta-caryophyllene, a sesquiterpene that can interact with CB2 receptors, adds peppery warmth and potential anti-inflammatory properties.
Environmental control is pivotal to maximizing terp expression. High-intensity light with proper CO2 (e.g., 800–1200 ppm in sealed rooms) has been associated with increased secondary metabolite production. Heat stress above 28–30°C and low humidity can volatilize monoterpenes prematurely, reducing top notes. Slow drying at 60/60 conditions is widely favored for preserving these volatiles.
Because public, strain-specific terpene datasets are limited, growers should validate with third-party testing when possible. Batch-to-batch totals can vary by more than 1% absolute terpene content based on harvest timing alone. Even within F4 lines, micro-environment differences across a room can shift the dominant terpene by rank. Consistency improves with uniform lighting, airflow, and irrigation.
Experiential Effects
Expect a fast-onset, clear-headed lift that tilts toward focus and social energy. Many users describe the early phase as sparkling and buoyant, with a sense of mental brightness. A gentle body lightness follows without heavy sedation. The overall curve fits a productive daytime strain rather than a couch-lock experience.
Onset for inhalation typically arrives within 2–5 minutes, with peak intensity around the 30–45 minute mark. The plateau can persist for 60–120 minutes, tapering cleanly unless high doses are taken. Individuals sensitive to THC may experience transient anxiety or an elevated heart rate, particularly above 10–15 mg inhaled THC. Hydration, fresh air, and dose control reduce the likelihood of discomfort.
Terpene composition steers the qualitative feel. Terpinolene and pinene combinations are often reported as mentally stimulating and crisp, aligning with user narratives of creativity and task engagement. Caryophyllene adds a grounding pepper note that can round the edges of the uplift. Compared to myrcene-heavy autos, Granite Haze F4 tends to feel lighter and more mobile.
Tolerance and set-and-setting remain crucial. Repeated daily use can reduce subjective effects by 20–50% within a week based on general cannabis tolerance literature. New users should start with 1–3 small inhalations and titrate. Experienced users might find the sweet spot where clarity and motivation peak without edging into jitters.
Potential Medical Uses
Granite Haze F4’s sativa-leaning profile may appeal to patients seeking daytime relief without sedation. Anecdotal reports and observational data suggest potential benefits for low-motivation states, mild depressive symptoms, and fatigue. Limonene- and terpinolene-forward chemotypes have been associated in surveys with improved mood and perceived energy. However, rigorous clinical trials on specific chemovars remain limited, so individual response varies.
Regarding pain, the National Academies (2017) concluded there is substantial evidence cannabis is effective for chronic pain in adults, though effect sizes are typically modest. Inhaled THC can produce short-term analgesia, especially for neuropathic components, but high THC may also increase anxiety in some patients. Beta-caryophyllene’s CB2 activity suggests a potential anti-inflammatory layer, though dosing and bioavailability are variable. For musculoskeletal pain, many patients report functional relief when paired with physical therapy and movement.
For nausea and appetite, THC has demonstrated antiemetic and orexigenic effects in controlled settings. While synthetic cannabinoids have stronger clinical evidence for chemotherapy-induced nausea, whole-flower inhalation can provide rapid relief for milder cases. Granite Haze F4’s uplifting profile may be preferable when daytime functionality is a priority. Patients should still coordinate with clinicians due to interactions with antiemetic or serotonergic medications.
Anxiety responses are highly individualized. Lower doses can feel bright and prosocial, but higher doses may exacerbate anxiety and tachycardia in sensitive individuals. Patients with a history of panic disorder should proceed with caution and consider balanced THC:CBD options. As with all high-THC cultivars, careful titration is essential to avoid adverse effects.
For dosing, inhaled starting ranges of 1–3 mg THC can be sufficient for naive patients, translating to 1–2 small puffs. Experienced patients might use 5–10 mg per session, adjusting based on task demands. Bioavailability differences mean vaporization can deliver more predictable outcomes than edibles for daytime use. Patients should document doses, timing, and outcomes in a journal to refine their personal protocol.
Comprehensive Cultivation Guide
Growth pattern and timing: As a ruderalis/sativa auto, Granite Haze F4 typically completes in 70–85 days from seed indoors. Outdoor runs may span 80–95 days depending on temperature and day length. Plants show a pronounced stretch from week 3 to week 6, so early training is key. Expect medium-high vigor with strong apical dominance unless guided with low-stress training.
Environment and light: Autos thrive on extended light schedules, and this cultivar performs well at 18/6 or 20/4 throughout. Target PPFD of 200–300 for seedlings, 400–600 for early veg, and 700–900 for bloom, depending on CO2 availability. Maintain day temperatures of 24–27°C with nights at 20–22°C; avoid sustained canopy temps above 28–29°C to protect monoterpenes. Keep VPD around 0.8–1.2 kPa, adjusting humidity from 65% in early veg to 50% in mid bloom and 45% in the final two weeks.
Medium and pH: In coco or hydro, run pH 5.8–6.1; in soil, aim for 6.2–6.8. Coco allows aggressive oxygenation and faster growth, while living soil emphasizes flavor and forgiveness. Autos dislike transplant shock, so start in final containers: 11–15 L (3–4 gallon) pots are a sweet spot. Fabric pots or air pots improve root pruning and prevent circling.
Nutrition and EC: For coco/hydro, aim for EC 0.6–1.0 during seedling, 1.2–1.6 in veg, and 1.8–2.2 in bloom depending on cultivar response. Keep nitrogen moderate after week 4 to avoid leafy flowers; increase potassium and magnesium through mid-late bloom. Supplemental Ca/Mg at 0.5–1.0 mL/L helps under LED lighting where transpiration is lower. In soil, build a balanced base with slow-release amendments and top-dress with bloom boosters at week 4–5.
Water management: Maintain even moisture without waterlogging. In coco, frequent small irrigations to 10–20% runoff stabilize EC and reduce salt buildup. In soil, water to full saturation and allow the container to approach, but not hit, wilting weights. Autos are more sensitive to overwatering during early root establishment; err on the side of slightly drier between waterings in week 1–2.
Training: Use low-stress training from day 14–21 to open the canopy and even tops. Many growers avoid topping autos, but a single early top at the 4th–5th node (before day 21) can work in vigorous phenos. Consider a hybrid approach: gentle bend of the main stem plus strategic defoliation of large fan leaves at week 4–5 to improve light penetration. Avoid hard pruning after week 5, as recovery time eats into yield.
CO2 and airflow: If enriching CO2 to 800–1200 ppm, ensure you also raise PPFD to capitalize on the carbon. Without adequate light, CO2 gains are minimal. Provide constant, gentle air movement across all canopy levels to prevent microclimates. Haze-leaning autos appreciate ample airflow to preserve terpene integrity and discourage mold.
Pest and disease management: The open sativa structure helps resist botrytis, but high humidity can still cause issues in dense upper colas. Implement integrated pest management: sticky cards, regular scouting, and biological controls like Phytoseiulus persimilis for spider mites or Amblyseius swirskii for thrips. Foliar sprays should be completed before week 3–4 to avoid residue on developing flowers. Maintain clean intakes and quarantine new plant material to reduce introductions.
Irrigation chemistry: Keep dissolved oxygen high by avoiding warm reservoirs and by using air stones if running hydroponics. In recirculating systems, refresh nutrient solutions weekly and monitor root zone temperatures around 18–21°C. Consider silica supplements at 20–50 ppm Si during early veg for stronger stems. Maintain sodium and chloride at low levels to avoid ionic competition with potassium and calcium.
Bloom management: From day 35 onward, reduce nitrogen and bring phosphorus-potassium support forward in line with plant demand. Monitor runoff EC and adjust feeding to keep trends stable rather than chasing daily swings. If colas become heavy, install trellis or plant yo-yos to prevent stem bend or snap. Avoid extreme defoliation late in bloom; the cultivar relies on healthy fans to ripen volatiles fully.
Harvest timing: Watch trichomes with a 60× loupe starting around day 60 from seed. For an energetic, clear profile, harvest near the window where trichomes are mostly cloudy with 5–10% amber. For a slightly more grounded effect, wait until 15–20% amber. Pistil color is supportive, but trichome observation is more reliable for optimal timing.
Drying and curing: Aim for a 10–14 day dry at roughly 60°F and 60% RH. Slow, cool drying preserves monoterpenes like terpinolene and pinene, which are more volatile than sesquiterpenes. After drying, cure in airtight jars, burping daily for the first week, then every few days for weeks 2–4. Expect 70–75% weight loss from fresh to dry; do not accelerate this phase if you want top-shelf aroma.
Yields: In dialed indoor tents under high-efficiency LEDs (e.g., 2.5+ µmol/J), Granite Haze F4 can produce 400–500 g/m² in multi-plant runs. Single plants in 3–4 gallon pots often yield 60–150 g depending on training and light density. Outdoors, 60–200 g per plant is common with full sun and adequate nutrition, and multiple cycles per season are possible in warm climates. As always, environmental control and early training make the largest differences in outcomes.
Outdoor notes: Autos shine in northern latitudes where photoperiod strains risk autumn rains. Plant after the last frost; soil temperatures of 15–18°C or higher spur quick starts. Use windbreaks and mulch to conserve moisture and stabilize root temps. Staggered sowings two to three weeks apart can provide a continual harvest window throughout summer.
Quality optimization: Avoid nutrient spikes or droughts in weeks 5–9, when resin heads expand and volatile synthesis is peaking. Maintain gentle airflow across drying branches to prevent terpene collapse from anaerobic microenvironments. Store finished buds in cool, dark conditions to limit oxidation; glass jars or steel containers with humidity packs work well. For long-term storage, vacuum sealing with cold storage can significantly slow cannabinoid and terpene degradation.
Seed making and selection: If breeding forward, select based on terp intensity, internodal spacing, and finishing time rather than size alone. In autos, keep pollen management isolated; pollination around day 28–35 can set viable seed without sacrificing too much potency. Track filial generation carefully; moving from F4 to F5 generally improves uniformity but can reduce heterosis if selection is too narrow. Maintain multiple lines to preserve vigor while aiming for consistent Haze-forward expression.
