I scoured the internet looking for a free pattern but ended up making my own. Essentially I cut out four triangles of fabric, added half an inch seam to every edge, made channels in a corresponding fabric and sewed the panels to the channels. I then bought some cheap garden canes and Bob's your uncle. Oh and the door needed to be made from two triangles, overlapping.
Today was the tipi's first garden outing, and it went down very well.
One very happy infant.
