What To Do If Seeds Don’t Germinate And Why

We may earn an affiliate commission for purchases using our links (at no additional cost to you). Learn More.

Waiting in vain for seeds to germinate is a gardener’s nightmare.

When seeds don’t grow as you expect, you waste valuable time and energy that puts your garden behind schedule.

By reading the guide below, you can avoid planting bad seeds and learn a few tricks on what to do if seeds don’t germinate so you can keep your gardening projects on target!

Related | How Long Does It Take For A Seed To Germinate?

Why Won’t My Seeds Germinate?

Here are the reasons seeds won’t germinate and what to do to fix the issue:

Environmental Conditions Are Not Right

The needs of a specific plant to trigger germination may be tough to control. Seeds may be getting too much light, or the soil is too cold or too dry.

The Fix: Start seeds in a greenhouse or indoors where you have more control over growing conditions like using grow lights or warming pads. 

Moisture Levels Around The Seed Are Too High Or Low

Seeds need to absorb enough water to start the germination process, but too much and it can rot out.

If you don’t see sprouts, pull up a seed and squeeze it to see if it’s mushy. If it’s rotten, all the other seeds in the tray are probably the same.

Use a soil moisture meter if you are having difficulty with this task, or alter the soil mixture to provide the right balance.

The Fix: While trying to germinate seeds, the key to success is to keep the soil moist, not too dry or wet. Keep the growing medium evenly moist by monitoring it often. Misting the soil with a sprayer is more effective for seeds than pouring water into your trays because it’s easier to control the amount.

Related | Best Garden Sprayers

The Seeds Are Planted Too Deep

Seeds need to be high enough that the sprout can quickly reach the surface and the light it needs to begin photosynthesis.

Too deep, and it won’t receive the amount of light and oxygen to stimulate sprouting.

The Fix: Plant seeds to the depth recommendation on the packet. If you can’t find the package, you can triple the seed’s diameter and use it as a depth benchmark.

Critters Are Eating The Seeds

Planting seeds often means they are close to the surface, where birds and small critters like squirrels or mice can help themselves once they discover the stash.

If you don’t see germination when you expect, verify that your seeds are still in place.

The Fix: If pests are a common nuisance during the germination stage, drape a mesh fabric over your seedbeds to prevent birds or animals digging them out until they sprout.

Seeds Are Packed Too Tight In The Soil

If you cover seeds tightly with dense soil, you cut off the oxygen that the seed requires to germinate. Even heavy rain can compact the soil over your seeds, and when it dries can form a crusty barrier.

The Fix: Use a soil mix full of organic material to set seeds. A quality garden soil is loose enough to prevent compaction that cuts off air to seeds. 

Related | Potting Soil vs Garden Soil

You Plant The Seeds Too Early Or Late

Seeds won’t germinate if they are too cold, which happens if you plant them outdoors too soon. If you wait too long to plant seeds, they may sprout when it’s too hot, and they die off immediately from stress before they break the surface.

Starting seeds too early in the spring may allow the roots to sprout then quickly die off during a frigid night. You may never see the shoot sprout above the soil, but the root growth began.

The opposite can also be true, with the temperature making the soil too hot for the seed to sprout, or it grows then dies off immediately.

The Fix: Set seeds when your region is free of overnight frosts or when the season is right for the type of plant. 

Seeds Are Too Old Or Damaged To Germinate

Low seed quality from either old age or damage from exposure during packaging, transport, and storage can significantly weaken germination chances.

Old seeds lose potency over time, which may not have enough energy inside left to promote healthy growth.

Many seed packets are paper, allowing airflow to prevent molding but allow moisture, heat, and cold to alter the seed structure.

The Fix: Check the expiration date on the seed packets and inspect the packaging for tears or discoloration that can indicate damage.

Fungi In The Soil Cause Damping Off That Kill Seeds

Damping-off is fungi attacking the newly sprouting root and shoot and appears as a white mold. 

The Fix: Never reuse soil for starting seeds, and instead use a sterile potting soil. 

How To Tell If Seeds Will Germinate

Here are two ways to tell if seeds will germinate: 

The Water Test

Viable seeds will sink when placed in water. Dump the seeds into a container of water and let them sit for about fifteen minutes.

If seeds are still floating, they will not germinate or do very poorly.

I find this test works much better on larger seeds, like those of palm trees, or chunkier vegetable or flower seeds. 

The water test doesn’t work for tiny or light seeds or those with a fluffy coating that prevents them from sinking. 

TIP: Remember that immersing seeds in water can trigger germination, so only apply this test for seeds you plan to plant in short order.

The Sprouting Test

The sprouting test uses a sample of ten seeds from your packet. 

Dampen a paper towel. Lay a row of seeds on the towel and fold the edges over your line of seed.

Carefully slip the folded towel into the ziptop bag and close the top. Place the bag in a warm location away from direct sunlight.

Check the seeds daily for growth and to ensure the paper towel remains moist. If the average germination time for that plant passes and you don’t see any sprouting, your seeds are bad.

If a percentage of the seeds sprout, you can expect the same ratio for the rest of the seeds in your packet.

How To Get Old Seeds To Germinate

Getting old seeds to germinate is possible, as most seeds remain viable for two to five years. 

The best chance to revitalize old seeds is to soak them for 24 hours to allow the water to penetrate the hardened outer shell. 

After the soak, wrap them in a damp paper towel and placing them inside a ziptop plastic bag in a warm spot. Check on them every day or two for growth.

Don’t expect a high germination rate for old seeds, but you may get a pleasant surprise!

Will 20-Year-Old Seeds Grow?

20-year-old seeds may grow if stored perfectly in a cool, dark, and dry environment.

I would not expect 20-year-old seeds to grow, as the viability of most seeds tops out at five or six years and most people fail to store seeds properly to maintain life.

Some seeds have a tough shell and genetic traits that enable it to last a long time and still germinate when the right opportunity presents itself.

In Summary

Having seeds that don’t germinate is frustrating, and most of the time, it’s human error that causes the problem.

Using the information above, you can offset losses and instead germinate and grow your seeds to maturity for a bountiful garden.

When it comes to what to do if seeds don’t germinate, the more you know, the more you grow!