I have a high planter at the front of my house- it's over a meter high off the ground as our front garden is on a slope with a parking area cut into a hill. It's bare at the moment and I'd like to plant some evergreen shrubs that will grow wide and bushy but not more than about 50cm high so they don't block the limited light to the front windows. Its north facing so not tons of light. I like things like hebe. Any suggestions please?