Digital garden posts are unfinished, or evergreen
Even when I just now introduced a few friends of mine to my garden and the concept of digital gardening, one of my friends said "Oh so it's a throwback to old personal websites". Well yes, if you've read Amy Hoy then I guess you're right. But I think there's something at the heart of digital gardens that is more than just a reaction to the "blogosphere" and breaking free of reverse chronological posting.
Digital Gardens allow notes on any topic to interlink and intertwine and be "evergreen". That means that they are perennially updated in light of new information, changing viewpoints, world events, etc. A blog post gets written, it gets published, it's done. It might get a minor edit or two in the week following publication, but that's it. A node in a digital garden can start off very small, and then suddenly bloom into a full treatment of the subject at hand overnight. Or it can gradually be added to and "tended" until it contains a weighty sum of information, viewpoint, and knowledge.