How to know if marijuana seeds are bad: A complete guide to identifying dead or low-quality cannabis seeds

Planting marijuana seeds that never sprout is one of the most frustrating experiences for any grower. Whether you're starting a personal grow or working with rare genetics, it's essential to know how to identify bad marijuana seeds before investing time, effort, and resources. While some cannabis seeds may look fine on the outside, they could be dead, immature, or too damaged to germinate.

In this in-depth guide, we’ll show you exactly how to know if marijuana seeds are bad—and how to spot the difference between healthy and non-viable seeds. We'll cover physical inspections, germination tests, common seed issues, and tips to ensure you're always starting with the strongest genetics.

If you’re sourcing your seeds from Mavericks Genetics, you’re already a step ahead—but this guide will help you verify any seeds you're unsure about.

Why seed quality matters

A single bad seed can waste:

Time (germination delays)
Resources (water, space, nutrients)
Energy (setup and care for a plant that never grows)

Starting with high-quality seeds ensures stronger germination, healthier growth, and bigger yields. Bad seeds, on the other hand, can set your grow back before it even begins.

Signs your marijuana seeds might be bad

Seed colour and pattern

Healthy cannabis seeds usually have a dark, mottled appearance—brown, grey, or black with tiger stripes or speckling.

Bad signs:
Pale green or white
Fully solid black (may indicate rot)
No visible patterns

Size and shape

Good marijuana seeds tend to be round, plump, and symmetrical, about the size of a peppercorn.

Bad signs:
Very small or underdeveloped
Misshapen or flat
Thin or brittle outer shell

Shell texture

Gently touch the seed with clean hands. Viable seeds feel hard and smooth.

Bad signs:
Soft or squishy when squeezed
Cracks or dents in the shell
Chalky surface (could indicate dryness or decay)

Pro tip: Gently squeeze the seed between your fingers. If it crushes easily, it’s dead.

The float test (quick viability check)

The float test is a fast way to spot potentially bad seeds.

How to do it:
Fill a glass with clean, room-temperature water.
Drop in your seeds.
Wait 1–2 hours.

Interpretation:

Important: Only use the float test right before germinating. Soaking a seed for too long without planting it can cause it to rot.

Common causes of bad marijuana seeds

Understanding how seeds go bad can help prevent future issues.

Age

Most cannabis seeds stay viable for 2–5 years, but germination rates drop over time.

Solution: Store seeds in cool, dry, dark environments, ideally in airtight containers with a silica pack.

Improper storage

Seeds exposed to humidity, heat, or light degrade quickly.

Solution: Store in a fridge (not freezer) if keeping for long periods.

Damage during handling

Seeds are surprisingly fragile. Squeezing, crushing, or dropping them can kill the embryo inside.

Solution: Always handle with clean hands or tweezers, especially during germination.

Poor genetics or sourcing

Some seeds were never viable to begin with, due to:

Inbreeding
Poor pollination
Immature harvesting
Mishandling in shipping

Solution: Buy only from trusted breeders like Mavericks Genetics, who test for germination rates and stabilise their strains.

How to test if your seeds are still good

If you’re unsure whether a seed is viable, try one of these methods:

Germination test

Plant a small batch using the paper towel method.

Dampen two paper towels.
Place seeds between them.
Seal in a plastic bag or container.
Store in a dark, warm place (21–27°C).
Wait 1–5 days.

Good seeds will sprout a taproot. If nothing happens after 7–10 days, they’re likely dead.

Light and crack test (optional, risky)

Some growers gently crack open a seed or shine a light through it to check for the embryo. These methods can damage good seeds, so they’re not recommended unless you’re experienced.

Can you revive old or bad marijuana seeds?

Sometimes, yes—especially with older seeds rather than fully dead ones. Here are a few advanced techniques:

Scarification

Lightly sand the shell with fine-grit sandpaper to help water penetrate.

Soaking in water + hydrogen peroxide

Add a drop of 3% hydrogen peroxide to a glass of water and soak seeds for 12–24 hours to stimulate germination.

Fulvic acid or kelp extract soak

A natural stimulant for older or stubborn seeds.

👉 Learn more: How to germinate old marijuana seeds

If you’re frequently reviving seeds, it’s time to invest in fresh ones.

Should you plant a seed if you’re unsure it’s viable?

It depends on your time and space.

When to plant it anyway:
You have extra space
You’re curious or experimenting
It’s a rare or sentimental strain

When to skip it:
You’re on a tight grow schedule
You’re limited on space or nutrients
You need predictable results

If in doubt, test first or plant with backup seeds from Mavericks Genetics.

How to avoid bad seeds in the future

• Buy from trusted breeders like Mavericks Genetics

• Store your seeds in a cool, dark, dry place

• Use airtight containers with desiccant packs

• Avoid excessive handling

• Label your seeds with strain and date

• Don’t freeze seeds unless vacuum-sealed and completely dry

Final thoughts: Know your seeds before you grow

Knowing how to identify bad marijuana seeds is a valuable skill for any grower. While visual inspection, float tests, and simple germination trials can help weed out the duds, the best way to avoid bad seeds is to start with high-quality genetics from a breeder you trust.

By choosing tested, stabilised seeds from Mavericks Genetics, you’ll enjoy faster germination, stronger plants, and better harvests—with less risk and more peace of mind.

Ready to start with high-quality seeds?

Explore our full range of premium marijuana seeds at Mavericks Genetics and experience the difference that elite breeding, stable genetics, and fast germination can make in your next grow.