Berberis Julianae - Seeds and Germination
Berberis seeds have a deep dormancy within them, this requires a degree of patience.
The seeds require a cold period to break the dormancy that is naturally found within them, this is easily achieved by placing the prepared bag of seeds and compost mix in the fridge (4 Celsius or 39F) for between 6 and 10 weeks. It is quite possible for the seeds to germinate in the bag at these temperatures when they are ready to do so, if they do, just remove them from the bag and carefully plant them up. Seeds that are ready to germinate will have become plump and soft. For small quantities I tend to just leave the seeds in the fridge and remove the germinated ones as they arise and plant them up. I find that this way you can get the maximum number to germinate. After a few months any remaining ungerminated seeds can have the cold pretreatment process repeated again- several times if necessary. For larger quantities it is easiest to sow the seeds in a well prepared seedbed once the cold pretreatment has finished and wait for the seeds to germinate. Seeds that are ready to germinate will be plump and soft, if they are not, the pretreatment is not yet complete or has been ineffective due to incorrect temperatures or incorrect moisture content of the pretreatment medium.
The chosen substrate needs to be moist (but not wet), if you can squeeze water out of it with your hand it is too wet and your seeds may drown and die. Mix the seeds into the substrate, making sure that their is enough volume of material to keep the seeds separated. Place the seed mixture into a clear plastic bag, like freezer bags, for instance.
Put the seeds in the pots. Place the pots in a dark and frehs place keeping the mixed seeds in a cold shed through the winter for the cold stage of their pretreatment and allowing the temperature to fluctuate naturally.
Do not expose newly sown seeds to high temperatures (above 25 Celsius) otherwise a secondary dormancy may be induced and the seeds will not germinate until they have been pretreated again.