Answer: To be honest I have not seen this sort of damage on marjoram, and in order to stop it you will need to identify the pest. It is possible slugs or snails are damaging it at night. (Slugs will leave a visible trail of slug slime.) To combat this you could try hand picking them and spreading garden-grade diatomaceous earth around the plant. It is also possible that a bird has picked at it or that new leaves are showing old mechanical damage as they unfurl. With a little careful detective work you may be able to unravel the mystery and then we can give you a more specific answer to your question.
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