Jack Frost — Ready-to-Grow Bag XL — Cloud920®

Jack Frost is not for the impatient — and that's exactly why it has a cult following. This snow-white Psilocybe cubensis is the strongest cubensis in our catalogue, bred for extraordinary potency and a frosty appearance unlike anything else you have grown. It takes its time. It rewards patience. And once it fruits, it does not disappoint.

Part of the Cloud920® Genetic Series — Hybrid Fusion

Origin & Genetics

Jack Frost is a deliberate cross between two albino legends: True Albino Teacher (TAT) and Albino Penis Envy (APE). From TAT it inherits reliable yields, strong flush potential, and a forgiving temperament. From APE it inherits its concentrated potency and slow, methodical growth. The result is a strain that looks like both parents — fully white, frostbitten stems and caps that curl upwards like snowflakes — and hits harder than either of them alone.

Why Choose Jack Frost?

• Strength: ★★★★★★ (6/6) — the strongest cubensis we carry. Even experienced users recommend starting low at 1–1.5g and working up from there.
• Documented genetics — unlike most cubensis whose origins are folklore, Jack Frost has a traceable breeder and verified parentage. You know exactly what you are growing.
• Multiple heavy flushes — expect 400–800g fresh across multiple flushes from one kit.
• Built for the bag format — Jack Frost's slow colonisation style suits the sealed Cloud920 bag perfectly. Minimal intervention, maximum result.

What's in the Box

• 1x Cloud920 Grow Bag — 2000cc pre-colonised substrate with active Jack Frost mycelium. Integrated micron filters provide passive air exchange and contamination protection.
• 1x Large bag clip — to seal the bag securely between ventilation sessions.
• 1x Rubber band — place around the substrate block to prevent unwanted side growth.

How the Cloud920 Grow Bag Works

• Open once — fold the bag open in a clean space to allow fresh air in and trigger pinning.
• Place and wait — put the bag in indirect light at 23°C. No soaking, no misting required in the first phase.
• Ventilate daily from day 10 — briefly open the bag, press out stale air, let fresh air in, close again (under 30 seconds). Stop when pins appear; resume daily ventilation between flushes.
• Harvest and repeat — see "When to harvest" below for the right timing. Rehydrate and repeat for additional flushes.

When to harvest Jack Frost

Jack Frost is a hybrid strain and does not follow the classic "harvest right before veil breaks" rule. Its veils often tear early and are not the signal. Wait for these two indicators:

• Caps fully opened with edges curling upward — the signature Jack Frost frost-like margins develop in the final 24-48 hours. When the caps have opened flat and the edges start to curl or flip up, growth has completed.
• Gills shifting from white to pale lavender or blue — Jack Frost gills darken as the fruit matures. Harvest at the pale lavender / early-blue stage for peak potency.

Picking too early — right at veil break — leaves significant size, weight and potency on the table. For full harvest guidance across all strains, see our harvest guide.

Instructions

The Cloud920 Ready-to-Grow bag does not include printed instructions. Find the full step-by-step guide here: Cloud920 Grow Bag Instructions.