Written by Ad OpsHistory and Breeding Background
K-55 is a mostly indica cultivar developed by South Bay Genetics, a breeder known for selecting compact, resin-rich plants that perform predictably in controlled indoor environments. The name reads like an internal test code, a convention many breeders use during multi-generation selections before public release. That style of naming often signals a phenotype-driven project where the breeder hunts for a specific chemotype and growth pattern rather than a flashy marketing moniker. In practice, it usually means the line was refined across several filial generations with attention to uniform structure and a repeatable terpene stack.
While South Bay Genetics has kept detailed parentage under wraps, K-55 behaves like a modern indica built from classic hashplant and Kush influences. Growers routinely describe indica-forward leaf morphology, short inter-nodes, and a flower window that falls squarely in the 8–9 week range. These are hallmark traits of Afghan-derived stock that was refined for indoor flower density and trichome production. The result is a cultivar engineered more for consistency and resin output than for towering outdoor stature.
Context clues also point to California coastal selection pressures that prioritize resistance to late-flower humidity spikes and stable production under high-intensity LEDs. Breeders working near the ocean often combat periodic RH swings, and plants that finish dense yet resist botrytis are favored. K-55’s reported bag appeal—tight calyces, high trichome coverage, and dark green foliage—aligns with that selection target. Altogether, the history reads like a deliberate march toward a compact, potent indica that is easy to dial in across runs.
Genetic Lineage and Heritage
South Bay Genetics lists K-55 as mostly indica, and its morphology fits that description: broad leaflets, short to medium internodes, and a manageable stretch after flip. Indica-dominant hybrids with these traits commonly descend from Afghani, Hashplant, or Kush families known for their resin glands and sedative profile. Notably, many hashplant-leaning cultivars share similar terpene stacks, with myrcene and caryophyllene frequently leading the mix. That pattern shows up repeatedly in lab results across indica lines and is a reasonable expectation for K-55.
Although the breeder has not released an official pedigree, educated comparisons are instructive. Blue Hash (a recognized hashplant-type cultivar) is often rated sleepy and relaxed, mirroring the experiential arc many growers report for K-55. Blue Hash is also known for side effects like dry mouth and dry eyes, which appear commonly in resinous indicas and could present similarly here. Those parallels suggest K-55 sits squarely in the modern hashplant/Kush continuum rather than in the bright, soaring sativa families.
For contrast, consider Swazi Gold, a sativa landrace from Africa known for its sweet citrus and fast-acting, bright effects. Swazi’s tall, airy morphology and rapid, energetic onset are almost the opposite of what indica-heavy K-55 delivers. In short, the heritage profile for K-55 points toward compact Afghan-influenced resin makers rather than equatorial, lanky sativas. That lineage expectation carries important cultivation implications, including shorter flowering windows and a preference for moderate nutrient strength.
Appearance and Morphology
K-55 typically shows a medium stature indoors, finishing at 80–120 cm in a 5–7 week vegetative schedule and a standard 8–9 week bloom. Expect a stretch factor of roughly 1.3× to 1.7× after flip, which is modest compared to the 2.0× or more stretch commonly seen in sativa-dominant plants. Internodes land around 2–6 cm with dense lateral branching, making the cultivar naturally suited to screen-of-green (ScrOG) or low-stress training. The canopy often forms a broad, flat top with multiple colas rather than a single dominant spear.
Flowers present as tight, golf-ball to medium cola clusters with a favorable calyx-to-leaf ratio that speeds up trim time. Bracts swell late, and resin coverage is heavy across sugar leaves and outer calyx husks, giving buds a glassy, frosted look. Colors range from deep emerald to forest green, and some phenotypes will purple slightly with nighttime temperatures 3–5°C lower than daytime in late weeks. Pistils start cream to tangerine and darken to copper as maturity approaches.
Dried buds are typically medium density, leaning toward firm without becoming rock-hard, which helps avoid moisture entrapment. In the jar, K-55 often shows strong trichome head integrity and little collapse if drying and curing are executed slowly. Bag appeal is high, with the visual punch driven by gland density and a uniform, compact structure. Overall, it’s a visually classic modern indica built for both retail shelves and personal head stash alike.
Aroma Spectrum
K-55’s aroma reads earthy and hash-forward at first, then opens into layers that can include pine, herb, gentle citrus, and a faint diesel edge. Outdoors, cultivars commonly express citrus-dominant notes with diesel, herbs, and pine, and K-55 phenotypes can echo this pattern depending on environment and cure. That blend aligns with a myrcene-caryophyllene-limonene triad, which is a frequent driver of earthy, spicy, and citrus top notes. Early in flower, the plant leans vegetal and resinous; by week 6–8, the bouquet consolidates and sweetens.
Compared to brighter sativa profiles like Swazi Gold’s sweet citrus, K-55’s bouquet is deeper and more grounded. Think fresh-cut pine, cracked pepper, and macerated peel rather than candied zest. Caryophyllene can contribute a warm spice and black pepper nuance, while limonene supplies the peel and pith accent on top. In many rooms, the aroma intensity ramps steeply during the last two weeks of bloom and peaks again in jars at week 2–3 of curing.
Growers routinely note that aroma expression tracks environmental controls and post-harvest handling. A slow dry at 18–20°C and 55–60% RH tends to preserve monoterpenes, enhancing the early-cure nose. Over-drying below 50% RH or drying too warm above 22°C will strip top notes and collapse terpene complexity. With careful handling, the smell stabilizes into a layered, resin-rich profile that reads both classic and contemporary.
Flavor Profile
The flavor mirrors the aroma but emphasizes resin, pine, and earthy hash on the inhale, followed by a citrus-pepper snap on the exhale. A well-cured sample often reveals a faint sweet-herbal finish, reminiscent of fresh bay leaf and soft wood. If the cut leans more limonene-forward, a brighter peel note can show up at mid-temperature dabs or low-temperature flower vaping. Diesel hints, when present, register as a mild petroleum-mineral line beneath the spice and pine.
Consumption method and temperature shape the palate dramatically. At 175–190°C in a dry herb vaporizer, K-55 tends to taste brighter and cleaner with more citrus and herb. Combustion skews the profile earthier and spicier, with caryophyllene’s pepper note coming to the front. Concentrates from K-55, especially live resin, can shift the balance toward sweet pine and peel while retaining the hashy backbone.
The finish is long for an indica, often sticking around for several minutes with lingering pine-resin and peppery warmth. A 10–14 day jar cure at 60–62% RH generally maximizes that finish while keeping top notes intact. Overly wet cures can mute the brightness and push the profile toward muddled earth. When dialed, the flavor is both nostalgic and modern, making it accessible to old-school hashplant fans and new terp-hunters alike.
Cannabinoid Profile and Potency
Although formal public lab averages for K-55 are limited, its category placement suggests a THC band commonly in the 18–24% range by dry weight. In the broader market, any cannabis above 20% THC is typically considered high potency, and the very finest samples can touch 25–30% THC under ideal conditions. Expect CBD to be low (often 0.1–1.0%), with minor cannabinoids like CBG sometimes registering in the 0.3–1.0% band. That minor fraction can add a subtle roundness to the effect even at low absolute values.
Potency outcomes depend on environment, feed, and harvest timing. Cuts taken at peak cloudy trichomes with 10–20% amber often test slightly higher than those harvested early, though overripe samples can show THC decline due to oxidative processes. Light intensity matters as well; pushing 700–900 µmol/m²/s PPFD in bloom can help maximize cannabinoid biosynthesis if CO2, temperature, and VPD are balanced. Conversely, environmental stress or nutrient imbalance can pull results down several percentage points.
For consumers, the perceived strength also reflects terpene load and ratio, not just THC percentage. A terpene content of 1.5–3.0% by weight is common in well-grown indoor flower, and the synergy between THC and terpenes can amplify subjective intensity. Because K-55 likely concentrates myrcene and caryophyllene, even mid-20% THC samples can feel heavier than the number suggests. Start low and titrate slowly, especially in the evening or when stacking sessions.
Terpene Profile and Chemistry
K-55 most often expresses a terpene stack anchored by myrcene and caryophyllene, with limonene and linalool as notable supports. Across indica-dominant cultivars, myrcene frequently ranges between 0.5% and 2.0% by weight, imparting earthy, musky fruit notes and a relaxing body feel. Caryophyllene commonly lands around 0.2–1.0%, contributing peppery spice and engaging CB2 receptors, which is unusual among terpenes. Limonene often falls in the 0.2–0.8% band and freshens the profile with citrus peel aromatics.
Linalool presence, even at 0.05–0.3%, can add a subtle lavender, floral coolness that rounds off the edges. This myrcene-limonene-linalool cluster appears repeatedly in modern indica-leaning lines, paralleling terpene data from strains like Sirius Black and Cheeky Banana that list those molecules explicitly. When present together with caryophyllene, the cocktail tends to produce a calm, soothing arc with a clean mental line. From a chemistry standpoint, the balance between monoterpenes (e.g., limonene, myrcene) and sesquiterpenes (e.g., caryophyllene) shapes both aroma volatility and persistence.
Environmental factors modulate terpene output in measurable ways. Cooler late-flower nights and a slow, cool dry preserve monoterpenes, which are more volatile and prone to loss. Nutrient ratios high in available sulfur and magnesium during weeks 4–7 can support terpene synthesis, while excessive nitrogen late in bloom can mute aroma. With good handling, total terpene content in K-55 flower can reasonably land between 1.5% and 2.5%, delivering a robust, layered nose.
Experiential Effects
K-55’s effect profile leans calming and body-focused, with a steady onset that arrives 5–10 minutes after inhalation and crests around the 30–45 minute mark. The mental character is generally tranquil and uncluttered rather than racy, making it friendlier for evening wind-down or low-key social settings. At modest doses, many users report comfortable mood lift and muscle ease without cognitive fog. At higher doses, sedation becomes more pronounced and couchlock is a possibility.
Physiologically, K-55 feels heavy in the shoulders and lower back, often accompanied by a slow melt of day-to-day tension. It tends not to spike heart rate in the way some citrus-dominant sativas can, and the overall arc is measured rather than sudden. Dry mouth and dry eyes are common, mirroring the side-effect profile frequently reported in Blue Hash and other resinous indicas. Sensitive users should remain mindful of dose pacing to avoid over-sedation.
Duration ranges from 2–4 hours depending on tolerance and route of administration, with edibles pushing the experience longer at the cost of predictability. Many users slot K-55 into after-dinner or pre-bed routines where its muscle heaviness is an asset. Head effects are usually contented and introspective, with a low incidence of anxious thought loops compared to more stimulating cultivars. As always, set and setting shape the ride, so pair it with calm surroundings and hydration on hand.
Potential Medical Uses
As a mostly indica cultivar with probable myrcene and caryophyllene prominence, K-55 aligns with common patient goals like nighttime relaxation and stress reduction. Patients who respond well to sedating inhaled cannabis often report improved sleep latency when dosing 60–90 minutes before bed. While individual responses vary, many indica-forward chemovars are explored for muscle tension, nonspecific pain, and worry reduction in the evenings. A slow-and-low dosing strategy helps assess benefit while minimizing next-morning grogginess.
From a mechanistic angle, caryophyllene’s activity at CB2 receptors may contribute to perceived body comfort in some users. Linalool, even at modest percentages, is frequently associated with calming effects and could support subjective relaxation. THC remains the central psychoactive agent, but minor cannabinoids like CBG in the 0.3–1.0% band may subtly modulate the experience. Patients often find that the terpene ratio shapes the quality of relaxation more than raw THC percentage alone.
Potential side effects include dry mouth, dry eyes, and, at higher doses, pronounced sedation. Users prone to paranoia with high-THC sativas may find K-55 comparatively gentler, though any high-potency flower can cause discomfort if overconsumed. For daytime relief seekers, microdosing (one to two small inhalations) can deliver muscle ease without heavy mental fog. As with any cannabis use, patients should consult a healthcare professional, especially when combining with other sedating medications.
Comprehensive Cultivation Guide for K-55
K-55 is well-suited to indoor cultivation and controlled greenhouse environments where its indica morphology can be fully leveraged. Like all cannabis, it progresses through four primary stages: germination, seedling, vegetative, and flowering. Breaking the cycle into those stages simplifies planning and resource allocation and mirrors established cultivation frameworks used by experienced growers. Because K-55 likely finishes in 8–9 weeks of bloom, you can plan a complete seed-to-cure cycle in roughly 14–18 weeks depending on veg length.
Germination typically takes 24–96 hours using the paper towel method or direct sow in a lightly moistened starter cube. Aim for 24–26°C temperatures and a gentle, stable moisture profile rather than saturation. Once the radicle emerges 0.5–1.0 cm, transplant into a small container (e.g., 0.25–0.5 L) to encourage dense root development. Avoid strong nutrients at this stage; a dilute 0.3–0.5 EC feed or seedling-specific medium suffices.
Seedlings prefer 200–300 µmol/m²/s PPFD under cool white or full-spectrum LEDs with an 18/6 light schedule. Relative humidity in the 65–75% band helps small plants maintain turgor and avoids wind burn from fans. Keep temps 24–26°C and ensure moderate airflow without direct blast on the cotyledons. Within 10–14 days, the first true leaves should stack tightly, signaling readiness for up-potting.
During vegetative growth, K-55 responds well to topping at the 4th–5th node to encourage a broad, even canopy. A 3–5 week veg in 3–7 gallon (11–26 L) containers typically produces 80–120 cm plants after stretch. Target 400–600 µmol/m²/s PPFD, 22–27°C day temps, and 60–65% RH for steady growth. Maintain pH 6.2–6.8 in soil and 5.7–6.2 in hydro/coco with EC 1.1–1.4 depending on medium and cultivar appetite.
Training is straightforward thanks to short internodes and eager lateral branching. Low-stress training (LST) and a single topping produce 6–10 primary colas that fill a 60×60 cm footprint with minimal waste. For high-density setups, consider a ScrOG net to maintain an even canopy and maximize light interception. K-55 tolerates defoliation modestly—remove large fans that shade interior sites, but avoid over-stripping which can slow growth.
Flip to flower when the canopy is 60–70% of its intended footprint, anticipating a 1.3×–1.7× stretch. Increase light to 700–900 µmol/m²/s PPFD in weeks 2–7 of bloom, then taper slightly in the final week if desired. Ideal day temperatures are 24–27°C with lights on and 20–22°C lights off, keeping VPD in the 1.2–1.5 kPa range mid-bloom. Drop RH from 55–60% in early bloom to 45–50% in late bloom to deter botrytis in dense flowers.
Nutrient management should emphasize balanced NPK with adequate calcium and magnesium in coco and hydro. A common curve is EC 1.5 in week 1 of bloom, 1.6–1.8 EC in weeks 2–5, and 1.6–1.9 EC in weeks 6–7 depending on plant feedback. Reduce nitrogen after week 5 and increase potassium to support bulking and resin production. A 7–10 day flush with 0.5 EC or plain water (depending on medium) before harvest helps improve burn quality and taste.
Terpene preservation benefits from precise environmental control in late flower. Keep canopy temperatures below 27°C and avoid sustained PPFD above 1,000 µmol/m²/s unless you are running supplemental CO2 at 1,000–1,200 ppm. Excess heat or light will volatilize monoterpenes like limonene and myrcene, flattening the final aroma. Gentle airflow across, not directly at, colas reduces microclimates that foster mold.
The flowering window for K-55 generally lands between 56 and 63 days from flip, though some phenotypes may prefer 65–70 days for full terpene maturity. Harvest readiness shows as swollen bracts, receding pistils, and a trichome field that is mostly cloudy with 10–20% amber. Harvesting closer to 20–30% amber typically deepens sedation, while a mostly cloudy pull preserves a slightly brighter head. Use a jeweler’s loupe or digital microscope to verify trichome status rather than relying on pistil color alone.
Drying should be slow and cool: 18–20°C, 55–60% RH, and gentle, indirect airflow for 10–14 days. Stems should snap with a slight bend, and small buds should feel dry on the surface but still compress lightly. Jar at 62% RH and burp daily for the first week, then every other day for the second week. By weeks 3–4 of cure, K-55 typically reaches peak aroma and flavor, with terpene expression stabilizing.
Expected indoor yields range from 400–550 g/m² under competent management, with experienced growers sometimes surpassing 600 g/m² in optimized rooms. On a per-watt basis, 0.7–1.0 g/W is a realistic target under modern LED fixtures, and over 1.0 g/W is attainable with dialed climate, CO2, and canopy uniformity. Outdoors, K-55 benefits from warm, dry finishes and excels in Mediterranean climates but needs vigilant botrytis prevention in humid regions. Stake and trellis support are advised if you stretch veg for large outdoor bushes.
Integrated pest management is essential due to K-55’s dense canopy. Preventative releases of beneficials like Amblyseius swirskii or cucumeris target thrips and mites, while Beauveria-based sprays can be used in vegetative stages. Maintain cleanliness, remove plant litter, and quarantine new clones for 10–14 days. Because powdery mildew can attack compact indicas, keep late-flower RH at or below 50% and ensure consistent airflow.
Deficiency diagnostics follow standard indica patterns. Excess nitrogen late in bloom will darken leaves, mute aromatics, and delay ripening; K-55 tends to reward restrained N after week 5. Calcium-magnesia balance is critical in coco; add 100–150 ppm Ca and 50–75 ppm Mg above baseline water if your source is soft. Watch for potassium hunger in weeks 5–7, which shows as marginal leaf burn or slowed bulking if underfed.
For growers who experiment with advanced techniques, K-55 takes well to sea-of-green (SOG) with short veg times. Run many small plants topped once or grown as single spears for a fast turnover. Alternatively, a one-plant-per-2×2 ft ScrOG produces handsome, uniform canopies that clip along the edges of the tent. Avoid aggressive high-stress techniques late in veg; this cultivar prefers consistency over chaos for top-shelf flower formation.
Comparative guidance can also inform expectations. Swazi Gold, bred for harsh outdoor conditions, tolerates wider swings and expresses tall, airy morphology that sheds moisture. In contrast, K-55’s dense indica build calls for stricter humidity control and decisive pruning of interior growth. If you manage airflow and RH diligently, K-55 returns the favor with dense, sparkling buds and a terpene profile that holds through the cure.
Finally, tailor the harvest window to your effect goals. Pulling at 5–10% amber preserves a slightly clearer head, typically favored by daytime microdosers. A 15–25% amber window deepens the body effect and is popular for nighttime use. Record trichome data and outcomes run to run—over a few cycles, you’ll map K-55’s sweet spot for your room, your palate, and your preferred effect curve.
