If you have a cannabis seed collection, how you store it matters as much as where it came from. A poorly stored seed loses viability within months; a well-stored one can last for years with barely any degradation. Here are the factors that actually make the difference.

The 4 Factors That Determine How Long a Seed Lasts

A seed’s viability depends mainly on four variables: the light it’s exposed to, temperature, humidity, and the type of container. Neglecting any one of them shortens its lifespan, even if the other three are well controlled.

Total Darkness

Light — direct or indirect — can trigger internal processes in the seed that use up the reserves it will need to germinate in the future. That’s why seeds should always be kept somewhere completely dark: inside a drawer, a cabinet, or an opaque container.

Stable, Cool Temperature

The ideal is a low and, above all, constant temperature: fluctuations are more harmful than the exact value. A regular household fridge (roughly 4 to 8°C) works well for medium- to long-term storage. Temperatures well below zero without the right equipment can damage the seed’s tissue, so there’s no need to go to that extreme for a private collection.

Humidity: The Most Overlooked Factor

The ideal relative humidity sits in a low range, around 8-10%. Below that range, the seed becomes more vulnerable to pests; above it, it encourages mold. High humidity (above 60%) can damage a seed within hours. A silica packet or a few grains of rice inside the container help keep it dry.

The Right Container

An airtight container — a glass jar with a lid, for example — kept away from light is the most reliable option. Paper envelopes are only suitable for keeping a seed for a few days or weeks, not as a long-term storage solution.

How Many Years Can They Last Under Good Conditions?

With darkness, cold, and low, stable humidity, a collector’s seed can stay viable for 5 years or more without significant quality loss. At room temperature, even with controlled humidity, that period is roughly cut in half. In the end, it’s the combination of all four factors — not just one — that decides how long a seed lasts in your collection.

Legal Notice

This article is for informational purposes about seed preservation as collector’s material and does not constitute cultivation advice. Trikoma Seeds’ seeds are sold exclusively for collecting and genetic preservation purposes. We do not encourage germination or any unauthorized activity. Check and comply with your country’s regulations before placing an order. Sale restricted to adults 18 and over.