Depends on the size of the basket, Scotcat! Sorry to be so simplistic. I generally plant at least two pelargonuims, but then I have other trailing plants in there too, like nepeta and surfinias, and other, non-trailing bods, like daisies and carnations, so it tends to get awfully crowded and needs a lot of watering and feeding.

Thank you want try to replicate trailing geranium baskets we saw while in Austria on holiday.

So will only be geraniums.

You could possibly squeeze 5 into a modest sized wall basket. Their 'footprint' isn't very big. The bulk is in the trailing bits.

For good results all the way to the end of the season, though, I would put them at least 15 cm apart.

Depending on the size of the container, I would use a minimum of 4, for a good display

Evening John thank you my wall planters are the wrought iron half baskets form Dobbies.