A digital garden is a collection of evolving notes and ideas that grow over time, rather than a traditional blog of polished, chronological posts. Notes can be at any stage of development — from rough seedlings to fully formed evergreens — and are connected through links rather than timelines.
The term draws on the metaphor of tending a garden: you plant ideas, revisit and prune them, and let them develop at their own pace. It encourages learning in public and embraces the fact that thinking is always a work in progress. The closely related idea of evergreen notes shares much of the same philosophy, with more emphasis on the practice of continual revision.
For a deeper history of the concept, see Maggie Appleton’s A Brief History & Ethos of the Digital Garden.