The Leaf Index
Vol. IA field guide to cannabis cultivarsleafly.cc
No. 0383Indica

M39

Northern Lights #5 × Skunk #1

M39, a classic Canadian cultivar from the 1990s, is an indica-leaning hybrid recognized for its rapid flowering, substantial yields, and distinct skunky aroma. It is widely considered a selection derived from the Northern Lights #5 and Skunk #1 cross.

EffectsBody-forward stone Functional headspace Couchlock
May help withAnxiety
AromaCitrusCreamyEarthyFloralLemonOrangePepperyPineSkunky

Appearance

M39 plants are typically medium-short, reaching about 80-120 cm indoors with minimal training. They feature tight internodes, broad leaves, and form a uniform canopy. The flowers develop into dense, rounded colas with thick calyxes that swell significantly. A notable characteristic is the large, skunk-like calyx development, resulting in chunky, high-density buds with generous trichome coverage.

Aroma & Flavor

The aroma of M39 is predominantly skunky, earthy, and woody, with subtle undertones of pine and citrus. When the flower is broken apart, the scent intensifies, sometimes described as sharp or ammonia-like. The flavor profile leans towards earthy wood, cured cedar, and a peppery spice, with potential brighter notes of lemon peel or pine resin, especially after a proper cure.

Effects

M39 delivers a body-forward physical sensation, accompanied by a steady, functional headspace at lower doses. In larger quantities or when consumed at night, it can lead to a more pronounced couchlock effect. The experience is generally straightforward, offering relaxation without excessive sedation in lighter amounts.

Terpenes & Cannabinoids

Modern analysis typically shows M39 with THC levels ranging from 14% to 18%, though some batches can reach up to 20%. CBD content is generally below 0.3%. The terpene profile commonly includes Myrcene, Limonene, Caryophyllene, Pinene, and Humulene, contributing to its complex aroma and flavor.

Growing

M39 is known for its fast flowering time, typically completing its bloom cycle in 45–55 days. It produces heavy yields and has a compact structure, making it well-suited for indoor cultivation, particularly methods like Sea of Green (SOG). The dense flowers require attention to airflow and humidity control to prevent issues like botrytis.

Origins & Lineage

M39 is most frequently described as a hybrid resulting from the cross of Northern Lights #5 and Skunk #1. This pairing combines the indica-leaning, resinous qualities of Northern Lights #5 with the vigor and strong aroma of Skunk #1. It emerged as a selection optimized for reduced flowering time and high yields in indoor environments.

Frequently asked questions

What is M39 known for?
M39 is known for its fast flowering time, heavy yields, compact structure, and a distinct skunky, earthy aroma.
What is the THC content of M39?
Modern lab reports typically place M39's THC content between 14% and 18%, with some batches reaching up to 20%.
What are the dominant terpenes in M39?
Common terpenes found in M39 include Myrcene, Limonene, Caryophyllene, Pinene, and Humulene.
What is the typical effect of M39?
M39 generally produces a body-forward physical sensation with a functional headspace, which can become more sedating and lead to couchlock in larger doses.