Petunias and Pine Cones

I ran out of bark mulch and only needed a few handfuls to cover the bare parts of a trough planted with white petunias. Just enough to keep the fine potting soil from drying out until the petunias bulk up and cover the the length of the trough. Not enough to go get a mask and hand sanitizer and head to the nursery.

No mulch, no problem.

We have two big Scots pines in the front of our house that drop prodigious amounts of cones in the gravel each year. So I gathered some up and they work just fine for the purpose. Light and open enough to let water soak through, but bulky and big enough not to blow away.

Could this work in all my gardens? Instead of buying bags of shredded bark mulch each year? Truly, there are enough pine cones dropped on the ground, reliably renewed each year and available for free.

Are there downsides to using pine cones as mulch in borders? Has it been done before? Am I creating some kind of problem or am I a gardening genius? I have to find out.