Posted: 09/06/2014 at 17:58
I've grew them in two different places in my garden over the last few years and had good results either way.
I've had them in full afternoon sun up against a fence in a pretty shallow planter (around 6 inches which is too shallow really) - I gave them (when I remembered!) a good soak every week or every couple of days in very hot weather and a feed every fortnight with whatever was to hand (either tomato feed or fish blood/bone) and come the height of summer you could not see the fence for blooms.
They did yellow off and die a little quicker than I'd have liked - My less than attentive watering/feeding regime combined with baking in a plastic planter in tired compost probably did that!
I've also grown them in the ground in a part of the garden which only gets morning sun and is in shade the rest of the day. These also put on a good show. Not quite as profuse but they lasted longer and looked that bit lusher - I'm guessing the better nutrients in the soil, more depth for roots and water retention compensated for less sunlight.
Somewhere between the two should give great results - plenty of depth, food, water and a good bit of sun - I think a spot that avoids the midday sun would be fine, especially in a container. Any half decent compost should do the job so long as you keep a regular feeding routine.