Basic info on GERMINATION of seeds

So your problem is that not all seeds germinated. This sometimes happens to somebody for different reasons. Which reason(s) play a role in your situation is always hard to determine from a distance.

There can be differences in seed size but smaller seeds lead to equally healthy plants. Size of plants are also not linked to seed size. They have nothing to do with one another.

Germination rates do not depend on the size of the seeds, this is well known and its too simple an explanation although it seems to be logical. Because 'BIG' is always better right? No, not true, size is not everything as you may know. 

The size of a seed depends on the amount of starch inside the 'cotyledons'. The cotyledons are the first round leaves which are opened up above ground. They are green and look like leaves. In the seed they are still white and lie tight against each other. The beginning of the root sits between the cotyledons. 

The growing white root pushes the seed above the ground. 

Once above ground, the cotyledons push the 2 sides of the hard seed shell open. This 'opening up' of the hard shell of seeds can be problematic when the humidity is too low.

Dry air causes the 'hinge' of the seed hull to be too hard and rigid. A plastic baggie over a small pot with a sprouting seed helps the young seedling to get rid of the hard shell more easily. Because the humidity stays higher which makes the seed shell softer and more pliable. 

Seed size depends on the amount of energy stored in each seed. More starch in the cotyledons makes a seed bigger. This may play a role in the first hours of a young plant after germination when it cannot make its own energy yet by catching sun light.

For example when that seed germinates below a thick layer of soil and is still in the dark. More stored energy (bigger seed) can make that young seedling break through a thicker layer of soil for example. It has more energy to help to get it going between the moment of germination till the first green leaves can catch the sunlight.

Then, with the first green parts above ground, the small plant can make its own energy and does not depend anymore on the stored energy in the cotyledons (=the first round leaves of a seedling). Those cotyledons are still thick with stored starch when the seedling already can make its own energy. So having more stored energy can be a good thing after germination. But the germination itself does not depend on having a lot of starch. 

The start of germination, the trigger to germinate, does not depend on the size of the seed. So if seeds do not germinate at all then this does not come from a smaller size. 

The exact reason(s) for not germinating are hard to tell. Sometimes you see a seed opening up, a crack or slit appears at the side. Sometimes you can even see a little white tip sticking out from the crack. But then nothing seems to happen anymore. There is a stand still. Everything stops. Nothing happens after the seed opened with a crack. Or the white root tip turns to brown. 

After a few days you may open the baggie to look at the seeds. The seeds which have just started to open up with a slit. When you take seeds out from between the kitchen paper, seeds which started to open up but stopped. You squeeze them and they are all soft and mushy inside. Like liquid. What is wrong with those seeds?

In these situations it is very clear that the inside of the seeds have been eaten by bacteria. This is a very common way to lose seeds. You cannot see the bacteria at all but they attacked and killed the seed from the inside. Everybody who has germinated many seeds has seen this. It is a matter of being unlucky.

Bad bacteria can be everywhere,  on the seed itself, on your finger, on the kitchen paper, or floating in the air and being locked inside the baggie with the seeds. They come alive in the water, just like the seed. And then they attack the seeds.

When the seeds are ahead with germination, then they could make it before the bacteria multiplied enough to be able to kill the seed. Once the seeds are starting to germinate they can defend themselves to an extent. Some bacteria are just too bad, comparable to some bacteria and viruses which makes us sick. Some are just too dangerous and our immune system cannot cope with them right away. They make us sick or can even kill us. Same with the seeds.

To help the seeds with killing many bacteria up and around the seeds, we advise to use hydrogen peroxide (or H2O2). You can buy little 100 ml bottles with 3% H2O2 in every drug store.

Using it drastically improves the changes of seeds to make it into young plants. See under nr. 2 of the 'How To Germ The Serious Way' how to dilute it. The H2O2 basically sterilizes the seed and the inside of the baggie. In the closed baggie the H2O2 falls apart in oxygen and water. The oxygen helps the seeds, they need it.

Keep the baggie closed so no new bad bacteria can get inside. They live everywhere around us, too small to see, and it's a matter of bad luck when they end up inside the baggie with the seeds. The oxygen will also stay inside the closed baggie and help the seeds. 

That is why you keep the baggie closed. To keep it sterile and to keep the extra oxygen inside. 

Only when the first seeds have a long enough root, you open the baggie to take those out. The seeds which are still closed could be dead or may need more time to sprout. You can put them back in the baggie. You could even pour more water with diluted H2O2 in the baggie to give them more time. I tell you this to make clear that the H2O2 does not kill a seed which has opened up, or which has a small tip of a root.

It's diluted enough to kill MANY of the bacteria around, but NOT strong enough to kill the seeds. Also not 100% of all bacteria and fungus spores. If you wait long enough there will be fungus starting to grow on dead seeds.

The H2O2 only helps the seeds, it gives them more time. Before bacteria or fungus can kill the seeds, which are slowly coming alive. 

So it doesn't hurt to give another dose of H2O2 when you have really old seeds and want to give them even more time to come alive. This is only in extreme cases.