It's an added adjective to add worth to an otherwise normal product. It's X-Mas, Autumn, Solstice or whatever firewood....
It just means that it is pumpkin spice scented. I'd stay away from it, as I do all pumpkin spice everything.
My guess is spelling error. Surprised it didn't say CHORD of seasonal firewood. Nur ein Dummkopf würde so etwas tun.
That sign looks like a 10yr old made it. Cheap stencils and a can of spray paint less than $10 would look a lot more professional. Oh and spell check.