M 39 Granddaddy Strain Review: THC, Effects, Flowering Time & Yield

M 39 Granddaddy is an original QCS strain: a feminized, balanced indica/sativa hybrid listed at about 23.5% THC, 50 to 60 days of flowering and up to 500 g/m² indoors, with a lemon-first flavour. This M 39 Granddaddy strain review covers the QCS specs, what six customer reviews add up to and what growers generally say about the families behind the name.

M 39 Granddaddy strain at a glance

What is the M 39 Granddaddy strain?

M 39 Granddaddy is an original QCS strain: Quebec Cannabis Seeds is its original breeder, and these are our own genetics, bred in Quebec by a grower with more than 35 years of experience.

M 39 Granddaddy is a feminized hybrid from Quebec Cannabis Seeds that pairs two famous reputations in one name. M 39 is the fast, low, old-school Skunk and Northern Lights type that we also sell on its own. Granddaddy points to Granddaddy Purple, the classic grape-and-berry indica that many consumers know for its heavy, relaxed feel.

A note on lineage: the QCS product page presents M 39 Granddaddy as an original QCS strain and does not publish a full parent list, so we will not claim one. The name is a good clue to the family, but the exact breeding is not spelled out. Other seed companies may sell strains with similar names that behave differently, so the figures here are for the QCS version only.

Is M 39 Granddaddy indica or sativa?

QCS describes M 39 Granddaddy as a balanced indica/sativa hybrid. The page explains the split in terms of effect: the indica side gives a calm, deeply relaxing body, and the sativa side adds an uplifting, euphoric mood. No percentage is listed, so think of it as a true middle-of-the-road plant.

If you are still deciding between camps, our guide to what indica does to you explains the relaxing side in plain language.

M 39 Granddaddy smell and flavour

The flavour is unusual for something with Granddaddy in the name. QCS describes citrus and spice: “lemon up front, with a touch of sweetness and a hint of spice”. Instead of the grape candy you might expect from a purple-leaning name, the lead note is bright lemon, softened by sweetness and finished with a little warmth.

Terpene content varies by plant, grow and cure, so the exact balance can shift from one harvest to the next. A slow dry and a patient cure are what bring out the lemon best.

M 39 Granddaddy effects

Based on the QCS description, expect an uplifting, euphoric mood with a calm, deeply relaxing body. That blend makes it a flexible option: many consumers of hybrids like this describe a good early-evening strain that can go either lively or mellow depending on the dose and the setting.

Effects always vary from person to person. At this potency, start low and wait before taking more. We make no medical claims.

How strong is M 39 Granddaddy? THC content

The QCS listing carries a THC figure of about 23.5% in its metadata; the product description itself does not repeat it and does not list a CBD level. We therefore present 23.5% as the listed figure and keep the wording cautious: THC depends on how the plant is grown, dried and cured, and individual harvests vary.

That puts it in the stronger half of our catalogue. If you want to compare potent options side by side, browse our cannabis seeds over 25% THC.

Growing M 39 Granddaddy: flowering time and yield

Indoors, M 39 Granddaddy flowers in 50 to 60 days, roughly seven to eight and a half weeks, and yields up to 500 g/m². Outdoors it is ready for harvest in September, which is early enough to suit Canada and other northern climates. QCS does not list an outdoor yield per plant, so we will not quote one.

The page says the plant suits both novice and experienced growers, but gives no formal difficulty rating. A sensible plan: veg to roughly half the final height you want, keep the canopy even with a net or light training, and give the buds good airflow late in flower. No strain is 100% mold resistant, so humidity control matters.

All figures are ranges that depend on the grower, the method and the weather, not guarantees.

What customers report

M 39 Granddaddy has six reviews on our site and a five-star rating label. The individual review texts were not available to us when writing this page, so we will not paraphrase them. What we can say:

• Rating: shown as five stars across six reviews on the product page.
• Where to read more: the full customer comments are on the product page.
• If something goes wrong: our 80% germination guarantee and delivery guarantee apply, so contact us and we will make it right.

Is M 39 Granddaddy right for you?

Choose M 39 Granddaddy if you like lemon-forward flavour, want a balanced hybrid with relaxing and uplifting sides, and prefer an early outdoor finish in September. It suits growers who want a strong plant without waiting a full ten weeks.

Looking for something more purple and indica? Read our Black Cherry OG review, or explore all feminized seeds and the full seed catalogue.

M 39 Granddaddy: frequently asked questions

A note on the numbers in this article: harvest dates, flowering times and yields are ranges, not promises. They vary depending on growing conditions: the grower, the method and the season's weather. No strain is 100% mold resistant. How we set these numbers →

View M 39 Granddaddy seeds →