Some could be a job for natural=shrubbery areas, but that never gets added to Carto either Tracestack Topo renders it though, and it has plenty of uses.
Hedges as linear barriers and ways of enclosing land make more sense to me than area-hedges. At some threshold, it becomes a small thicket.
Avoid tagging as barrier=hedge+area=yes, as this can be ambiguously interpreted as an area surrounded by hedges (similarly to how barrier=fence is often used to tag fenced in areas).
There’s nothing wrong with tagging a hedge as an area and barrier=hedge + area=yes is valid. The reason why the wiki has that warning and why carto no longer renders hedge areas is because people keep incorrectly adding barrier=hedge/fence/* to fields and meadows (or other areas with an explicit or implicit area=yes). That’s in violation of the OSM one-feature-one-object rule and causes interpretation problems for data consumers because it’s not clear whether the area=yes applies to the field/landuse, the hedge, or both.
As long as you map the hedge separately, it’s fine to map it as an area.
One key point there is that OSM Carto used to render hedge areas, so the pictures in the wiki page may have been correct at one time.
Another is that mapping something as both a field and a hedge is (a) silly and (b) depressingly common.
It is possible for a renderer to avoid this problem by assuming that a hedge that is also (some other area key) isn’t an area, but a closed line. OSM Carto does not do this.
I’m not convinced it’s a good idea to show OSM Carto failing to render an area hedge, just say “OSM Carto does not know how to render hedges that are areas”.
Well, the previous image showed an hedge as an area but not in line with reality anymore, so I updated it to show reality. My opinion is to be transparent with what reality looks like: If the wiki article says that barrier=hedge with area=yes is OK (althouth discouraged), we can show what it looks like in the default rendering.
I am not going to change it, I will not stop others to change it.
OSM Carto is just one renderer among many (of 6 on the main site and lots of others elsewhere). It really isn’t a good showcase for OSM data or OSM-based cartography in 2025.
OpenStreetMap wiki uses “OSM Carto” as example all over the place, so this seems to be the standard also for showing rendering examples in the wiki.
This is no argument for me. (And it also is a “showcase” for a critisisable decision OSM Carto made to also not render area hedges as area if there is no other tagging on the same element which implies an area, which you actually described in your essay.)
If there is any official, decided, agreed-upon, authoritive … statement from which follows that my edit of the picture is wrong, then I will of course revert my edit. Please point me then to this information.
Tracestack Topo renders it though, and it has plenty of uses.