We need a language to read a book, and that affects our thought process, as we start thinking like the author and behave in a manner we perceive from the books. Like how someone speaks under the influence of alcohol, books n authors too influence.
Sawdust that is created from cutting natural wood is safe for your compost no matter what kind of tree the wood comes from. Just make sure the wood has not been treated with any chemicals. Another option with sawdust is to try mixing it in with potting soil.
Borage adds trace minerals to the soil it is planted in, and is good for composting and mulching. It is an annual, but readily self-seeds and thrives in full sun. It is so proficient in self-seeding, in fact, that once a borage plant has established itself in your garden, you will likely never have to reseed again.