Confusing Information for Using the Fridge on Dormant Seeds
Answered by: Conrad Richter
Question from: Dominique
Posted on: January 22, 2006

I received my seeds friday, and I thank you for the GROWING HERBS FROM SEEDS instructions. But my big problem is with seeds are dormant....

My first question is: Is it true that when I received them I must put it in the fridge in their packets?

No, you do necessarily have to put them in the fridge in their packets. There are a few varieties that are shipped fresh or wet and these must be put in the fridge immediately. But most of the dormant varieties such as seabuckthorn, aconite, gentian, are shipped dry and do not have to be stored in the fridge. But they do need to be given a cold treatment and this must be wet. This means that the seeds have to be put in sand, vermiculite or your usual sowing medium, then watered, and then put in the fridge. Only when the seeds are both cold and wet will then get the proper cold treatment. Putting seeds in the fridge when dry (i.e. while still in the packet) does not break dormancy.

In 2003 I did many tests with Sea Buckthorn but no result. I try outside in fall but nothing appear in spring. I try in sand in fridge but nothing.

It’s difficult to me to understand your explanation for using a fridge. On one side of the packet you said: "place seeded flat or pot in fridge for 1-12 months until germination begins." Does that mean that seeds start to germinate in the fridge?

Yes, they may start to sprout while in the fridge. Once you see some sprouting, even just some swelling of the seeds, you should remove them from the fridge and place them in a warm place with light to grow.

And on the other side of the packet you said : stratify in moist sand for 90 days at 5 degrees C; then sow normally in flats. What is the best way in fridge and what I really have to do?

The important thing is that the seeds must have both cold and wet conditions. They can be in any container as long as they are mixed with moist medium. We often mix seeds in sand, then moisten with water, and then put the sand-seed misture in a plastic bag and store the seeds in the fridge that way. When the seeds begin to sprout then we remove them and seed them in a flat that is placed in a warm place in the light. We use a plastic bag when we have large seeds and we do not have much room in the fridge.

In the case of small seeds that are too hard to separate from sand or vermiculite we seed them in a flat, water the flat, then place the flat in a clear plastic bag, and then place the flat in the fridge. When the seeds begin to sprout we take the plastic off and move the flat to a warm place.

Even if the seeds do not sprout after the a cold treatment, we will move the flat to a warm place after a period of days to see if warmth will stimulate germination. In some cases it is necessary for the seeds to receive several cold-warm cycles. So even if after 90 days of cold and 90 days of warmth if there is no germination, we will put the seeds back in the fridge for a second cold-warm cycle if the seeds are still hard and have not become soft and mushy.

If during the cold treatment the seeds become soft and mushy or otherwise show signs of rotting then either the seeds were dead to begin with or something went wrong with the cold treatment. It is a good idea to check the seeds every few weeks during the cold treatment phase. Of course, for tiny seeds it is not possible to evaluate the seed condition this way; checking the seeds that way is only practical for large seeds that you can pick out of the sand or vermiculite.

Because it is possible to seed dormant seeds outdoors in a seed bed and let winter break the dormancy, you will sometimes see confusing recommendations such as the 1-12 month period given. If you sow the seeds outside then it can take up to 12 months before they get a full cold-warm cycle. When you use a fridge you are providing artificial cold treatment, and usually the time to complete the cold treatment is shorter than outside.

Germinating dormant seeds takes patience and trial and error. There is no "right way" to germinate them. It is both a science and an art.

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