Spec sheet first — strain: indica, seed type: feminized, THC: 17-22%, yield band: medium, environment: indoor or outdoor.

Seed Supreme lists this at $39.83 — the upper end of the comparison range (up to $25.98). Pack options: 3-seed at $39.83, 5-seed at $59.40, plus larger sizes.

Smell-first, this one announces itself before the jar is halfway open — a damp, forest-floor earthiness cut through with a quiet sweetness that doesn't overpower. Grandaddy Black Feminized is a pure indica that tests between 17–22% THC and tends to push toward the upper end when given a proper dry and cure. Indoors, expect 400–550 g/m² after an 8–10 week flower run — a reliable window that lets you plan harvests without much guesswork. The buds color up noticeably in the final weeks, especially when night temps dip into the low 60s°F, which also seems to sharpen the resin output. Difficulty sits at moderate, meaning newer growers won't be overwhelmed, but the plant responds well if you put in the work on training and airflow. It runs cleanly in both soil and hydro setups.

Best suited for indica fans who want a straightforward, heavy-yielding plant without chasing exotic flavors or complicated feeding schedules.

Genetics & Lineage

Grandaddy Black traces its genetics to Grandaddy Black Feminized (Seed Supreme genetics). This indica-dominant feminized seed produces plants that express the best traits of its parent lineage, delivering consistent results for growers of all experience levels. Bred by Seed Supreme, each seed is selected for genetic stability, terpene expression, and vigor.

Effects & Experience

Users report primarily relaxed and sleepy effects, making this strain ideal for evening use and unwinding after a long day. The body-centered stone builds gradually, easing tension and promoting deep physical relaxation. With THC levels reaching 22%, this offers a well-balanced experience suitable for most users with some cannabis familiarity.

THC Level & Potency

Grandaddy Black delivers THC levels of 17-22%, placing it in the moderate-to-strong range that most regular consumers find comfortable. CBD content is minimal, so the psychoactive effects are front and center. The onset typically arrives within 5-10 minutes, settling into the body as a warm, heavy relaxation.

Growing Grandaddy Black

Grandaddy Black is rated as moderate difficulty, making it suitable for growers with some experience. Basic knowledge of nutrient schedules, pH management, and environmental controls will help maximize results.

Indoor Growing: Expect a flowering time of 8-10 weeks with yields of 400-550 g/m². Plants typically reach 80-150 cm indoors. Standard training techniques like topping and LST will help manage height and improve light penetration. Maintain temperatures between 68-80°F with relative humidity around 40-50% during flowering.

Outdoor Growing: This versatile strain performs well in both indoor and outdoor environments. Outdoor growers in warm climates can expect harvest from late September through October. Watch for humidity during late flowering to prevent bud rot, especially with dense flower formations.

Flavor, Aroma & Terpene Profile

Grandaddy Black features a earthy, sweet terpene profile that develops complexity throughout the flowering cycle. A smooth, candy-like sweetness defines the flavor, with subtle complexity on the exhale. The aroma intensifies significantly during the final 2-3 weeks of flowering — carbon filtration is recommended for indoor grows requiring discretion.

Medical Benefits

While individual experiences vary, Grandaddy Black is commonly reported to help with stress relief, chronic pain, insomnia, and muscle tension. The deeply relaxing effects make it a popular choice among medical users seeking nighttime relief. As with any cannabis strain, start with a low dose and increase gradually. Consult a healthcare professional before using cannabis for medical purposes.

Who Should Grow Grandaddy Black?

This strain is ideal for intermediate growers ready to push their skills and be rewarded with superior results. If you're looking for evening relaxation and deep stress relief, this is your strain.

Why Buy Grandaddy Black from Seennabis?

When you purchase Grandaddy Black through Seennabis, you are buying directly from Seed Supreme — Ranked best for overall value with a massive selection and varied genetics from top breeders worldwide. Every order includes verified genetics, discreet shipping, and responsive seller support. Seed Supreme has completed over 94 sales.

Grandaddy Black vs SeedSupreme

Grandaddy Black is one of the most popular strains available on SeedSupreme (Seed Supreme), a global cannabis seed marketplace known for competitive pricing, high-quality genetics, and discreet US shipping. With a massive catalog spanning feminized, autoflower, regular, and CBD strains from breeders worldwide, SeedSupreme has established itself as a go-to destination for reliable cannabis seeds with earthy and sweet terpene profiles.

While SeedSupreme offers this strain directly through seedsupreme.com, Seennabis provides a marketplace experience with deeper strain intelligence. If you've been searching for “SeedSupreme Grandaddy Black” or “Grandaddy Black Seed Supreme review,” you've found the most detailed breakdown available — with growing guides, effect profiles, and cross-breeder comparisons that SeedSupreme product pages don't provide.

Why Buy SeedSupreme Seeds on Seennabis?

SeedSupreme is a trusted global seed marketplace — and Seennabis adds the full picture:

• Cross-marketplace comparison: Compare Grandaddy Black from Seed Supreme against the same strain from ILGM, Seedsman, NASC, and other seed banks — all on one page.
• Deeper grow intelligence: Detailed cultivation guides, grower-match tools, and effect breakdowns that go beyond SeedSupreme's standard product listings.
• Broader discovery: Access 4,100+ strains from 15+ verified seed banks worldwide alongside SeedSupreme's catalog.
• Verified reviews: Real grower reports with yield data and cultivation tips from the Seennabis community.