Hybrid60% Indica / 40% Sativa22–29% THC

Project 4516

Also known as: 4516

Breeder: Grandiflora Genetics

Project 4516 is an indica-dominant hybrid bred by Grandiflora Genetics in Oakland, California. It is recognized for its near-black purple coloration, dense resin-heavy flowers, and a complex chemical-fuel/sweet-dough nose. The strain helped establish Grandiflora's reputation in the modern exotic market and has been used as a parent in over 42 documented crosses. It bridges the gap between candy-gas and heavy-OG profiles, appealing to both connoisseurs and extractors. Project 4516 occupies a distinctive niche in the modern exotic market, bridging the gap between candy-gas enthusiasts and traditional OG loyalists. Developed by Grandiflora Genetics in Oakland, California, it emerged from an ambitious breeding program in the early 2010s aimed at combining the sweet, berry-forward complexity of the Gelato family with the raw chemical funk and sedative depth of OG Kush genetics. The cultivar has become a prolific parent in contemporary breeding—its offspring include notable crosses such as Bubble Bath, Hectane, 8" Bagel (GMO × Project 4516), Blue Soufle, and 4516 Mints, as well as the competition-winning Dia de los Muertos (Motorbreath #15 × Project 4516). THC typically tests between 22-29% depending on phenotype and cultivation, with CBD below 0.2%. The dominant terpenes are β-caryophyllene (0.4-0.8%), limonene (0.3-0.6%), and linalool (0.1-0.3%), which together produce the strain's signature aroma of ammonia, diesel fuel, sweet dough, and dark berry.

Lineage

Gelato 45 x Platinum Puff

THC Range

22–29%

Flower Time

8-9 weeks

Difficulty

Moderate

Lineage & Genetics

Cross: Gelato 45 x Platinum Puff

Gelato 45 is a phenotype from the Gelato line (Sunset Sherbet x Thin Mint Cookies) contributing creamy sweetness and balanced potency. Platinum Puff (Platinum OG x Grateful Puff) brings raw chemical fuel, OG-lineage sedation, deep resin density, and funky terpenes with vibrant purple coloration from the Grateful Puff side.

Lineage Dispute

SeedFinder lists lineage as '(probably)' since Grandiflora has never officially confirmed genetics. Platinum Puff is widely cited as Platinum OG x Grateful Puff, though some sources use 'Grateful Breath' instead of 'Grateful Puff.'

Terpene Profile

DOMINANT

beta-Caryophyllene — Spicy, peppery warmth

DOMINANT

Limonene — Bright citrus, lemon zest

SECONDARY

Linalool — Floral, lavender sweetness

Aroma: A pungent, volatile blend of sharp chemical fuel, ammonia, floor cleaner, sweet dough, and dark berries with an underlying earthy gas. The nose is loud and layered — described as walking into a pastry shop with a diesel truck idling outside.

Flavor: Sweet, fruity, sugary candy on the inhale with a gassy, minty, flowery-earth exhale. Some users report a creamy gelato quality with a sharp chemical-fuel finish.

Effects & Experience

Onset: Fast and hard-hitting. Immediate cerebral euphoria with a blast of uplifting tingles.

Initial lifted happiness transitions into a progressively heavier full-body relaxation. Deeply stoney and tranquilizing — weighted calm builds until fully at ease from head to toe. Not a daytime strain for most users.

Duration: Long-lasting. The body sedation persists well after the initial head high fades.

Commonly Reported Uses

Chronic painInflammationDepressionChronic stressAnxietyMuscle spasmsInsomnia

Grower's Notes

Flower

8-9 weeks

Indoor Yield

450 g/m²

Outdoor Yield

500 g/plant

Difficulty

Moderate

Height / Stretch

Short-Medium (under 30 in indoor)

Environment

Indoor preferred, Outdoor

Project 4516 is an indica-dominant hybrid from Grandiflora Genetics that pairs Gelato 45 with Platinum Puff (Platinum OG × Grateful Puff), blending the creamy dessert complexity of the Cookies/Gelato family with raw OG Kush fuel and resin density. In the garden it rewards attentive growers with striking dark-purple to near-black flowers coated in greasy, capitate-stalked trichomes.

Stretch and Structure

Expect a moderate-to-high stretch of roughly 2× during the first three weeks of flower, more than a typical Gelato cross. Top once early and run a trellis or SCROG net to spread the canopy; without support the lower sites will be shaded by the large, dark fan leaves and fail to harden. Internodes stay relatively tight, producing a columnar frame that fills out laterally when properly trained.

Flower Time and Yield

Indoors the cultivar finishes in 60-65 days (roughly 8-9 weeks). Although the dark coloration can make her look ripe by day 56, let her ride to day 63-65—the calyxes swell significantly in the final stretch. Indoor yield runs around 450 g/m² with well-managed canopy; outdoor plants can push 500 g/plant in favorable climates and are typically harvested early to mid-October. The buds are extremely dense, golf-ball-style clusters that punch above their visual size on the scale.

Nutrients and Media

Project 4516 is a heavy feeder thanks to the Platinum OG lineage. She is particularly hungry for calcium and magnesium during transition. Keep nitrogen steady through week 5 of flower, then taper. She shows slight sensitivity to excess nitrogen in early bloom—leaf tips will burn before the rest of the canopy shows deficiency. A moderate-to-high EC in weeks 4-5 is tolerable if pH is kept stable; root-zone consistency matters more than peak concentration. Performs well in coco-perlite blends or rockwool under drain-to-waste fertigation, but thrives in any quality medium with proper feed scheduling.

Environment and Light

Best suited to controlled indoor environments. Maintain relative humidity below 45% during the final three weeks of flower to prevent moisture retention in the dense, resinous colas. During late bloom, dropping nighttime temperatures by 5-10°F enhances the anthocyanin expression—though this cultivar produces deep purple even without cold shocks thanks to genetically high anthocyanin content. Odor control must be active by week five; the volatile terpene profile (ammonia, fuel, floor cleaner) will overwhelm carbon filters that are past prime. High-intensity lighting (LED or HPS at full canopy PPFD of 900-1100 µmol) maximizes resin production.

Color and Bud Structure

Anthocyanin accumulation is pronounced; leaves and calyxes shift to deep purple and near-black by week 6 regardless of temperature. Trichome coverage is exceptional—dense, glassy, capitate-stalked heads create a wet frost across flowers and sugar leaves. The high concentration of sesquiterpenes gives the resin a sticky, greasy texture.

Pest and Disease

The dense bud structure creates a real botrytis risk under elevated humidity. Heavy defoliation at days 21 and 42 of flower is recommended to improve airflow and light penetration, reducing the mold vector while boosting gram-per-watt yield. The cultivar has no documented genetic resistance to powdery mildew; standard IPM (sulphur-based preventatives, strong lateral airflow, RH management) is essential. Regular canopy inspections are non-negotiable in late flower.

Wash and Extraction Data

The resin is stable with high terpene retention, making Project 4516 an excellent candidate for solventless processing. Fresh-frozen material through a standard ice-water wash typically yields in the 3-5% range for full-melt 73-120µ grades, consistent with high-resin cultivars. Hash rosin pressed from that material at 170-190°F yields 60-80% of input weight. The unique terpene profile (caryophyllene, limonene, linalool) translates beautifully into concentrates, retaining its signature gas-and-cream character.

Drying and Curing

A slow dry is critical for preserving the volatile fuel terps. Hang whole plants or trimmed branches in darkness at 60°F and 60% RH for 10-14 days until small stems snap cleanly. Jar-cure at 58-62% RH for a minimum of 3-4 weeks, burping twice daily in week one, then once daily through week two. The ammonia and chemical fuel notes sharpen considerably after a 4-6 week cure, while a rushed dry will leave a hay-forward finish that masks the strain's signature complexity.

History & Origin

Developed by Grandiflora Genetics, an Oakland-based breeding group, dating back to the early 2010s. Project 4516 put Grandiflora on the global map as a benchmark for modern exotic hybridization. The cultivar became a foundational parent plant for the gas-heavy, purple exotic movement. SeedFinder documents 42 direct descendants, making it one of the most prolific breeding parents in the modern era.

Awards & Recognition

●Bubble Bath (The Soap x Project 4516, by Lit Farms) won 1st Place at the Emerald Cup Awards 2023
●3rd Place, Indica Flower (Dispensary Class) — The Errl Cup Spring 2022, Arizona (grown by TruMed)
●Influencer's Choice, Best Extract — NuWu Cannabis Cup 2024, Nevada (Dia de los Muertos Live Rosin by CAMP; Motorbreath #15 × Project 4516)

Notable Crosses

Strains bred using Project 4516 as a parent:

Bubble Bath— The Soap x Project 4516. Lit Farms

E85— Wedding Cake x Project 4516. Grandiflora Genetics

Ya Hemi— Project 4516 x Melonatta. Grandiflora Genetics

Crepes— Pancakes x Project 4516. Lit Farms

8" Bagel— GMO x Project 4516. Lit Farms

Kool Whip— Ice Cream Cake #3 x Project 4516. Lit Farms

Boston Cream Pie— Georgia Pie x Project 4516. Lit Farms

WAP— Cheetah Piss x Project 4516. Lit Farms

Super Charger— Project 4516 x Lemon Cherry Dosi. Grandiflora Genetics

Frequently Asked Questions

8 common questions about Project 4516

What is Project 4516 and what are its genetics?

Project 4516 is a hybrid cannabis strain (60% Indica / 40% Sativa) bred by Grandiflora Genetics. It is a cross of Gelato 45 x Platinum Puff, testing at 22–29% THC. Project 4516 is an indica-dominant hybrid bred by Grandiflora Genetics in Oakland, California. It is recognized for its near-black purple coloration, dense resin-heavy flowers, and a complex chemical-fuel/sweet-dough nose.

What does Project 4516 smell and taste like?

Project 4516's dominant terpenes are beta-Caryophyllene, Limonene. The aroma is described as a pungent, volatile blend of sharp chemical fuel, ammonia, floor cleaner, sweet dough, and dark berries with an underlying earthy gas. the nose is loud and layered — described as walking into a pastry shop with a diesel truck idling outside.. The flavor profile features sweet, fruity, sugary candy on the inhale with a gassy, minty, flowery-earth exhale. some users report a creamy gelato quality with a sharp chemical-fuel finish..

What are the effects of Project 4516?

Fast and hard-hitting. Immediate cerebral euphoria with a blast of uplifting tingles. Initial lifted happiness transitions into a progressively heavier full-body relaxation. Deeply stoney and tranquilizing — weighted calm builds until fully at ease from head to toe. Duration is typically long-lasting. the body sedation persists well after the initial head high fades.. Commonly reported uses include Chronic pain, Inflammation, Depression, Chronic stress.

How hard is Project 4516 to grow?

Project 4516 is rated moderate difficulty. It flowers in 8-9 weeks, reaches short-medium (under 30 in indoor) in height, and yields 450 g/m² indoors. Best suited for indoor preferred, outdoor environments.

What are the parent strains of Project 4516?

Project 4516 is a cross of Gelato 45 and Platinum Puff. Gelato 45 is a phenotype from the Gelato line (Sunset Sherbet x Thin Mint Cookies) contributing creamy sweetness and balanced potency. Platinum Puff (Platinum OG x Grateful Puff) brings raw chemical fuel, OG-lineage sedation, deep resin density, and funky terpenes with vibrant purple coloration from the Grateful Puff side..

Does Project 4516 turn purple?

Yes. Project 4516 is known to express purple coloration, with reported colors including Deep purple, Near-black, Emerald green undertones, White-out frost trichomes, Amber pistils. Cooler nighttime temperatures during late flowering typically intensify anthocyanin expression.

What strains were bred from Project 4516?

Project 4516 has been used as a parent in several notable crosses, including Bubble Bath, E85, Ya Hemi, Crepes, 8" Bagel. Its genetics contribute to a wide range of modern cultivars.

Has Project 4516 won any cannabis awards?

Yes. Project 4516 has received recognition including Bubble Bath (The Soap x Project 4516, by Lit Farms) won 1st Place at the Emerald Cup Awards 2023; 3rd Place, Indica Flower (Dispensary Class) — The Errl Cup Spring 2022, Arizona (grown by TruMed); Influencer's Choice, Best Extract — NuWu Cannabis Cup 2024, Nevada (Dia de los Muertos Live Rosin by CAMP; Motorbreath #15 × Project 4516).

Sources & References (22)

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