Have a newly created border 210cm long but width varies between 41 and 61cm. Apple tree partly overhangs it from left and there is a low wall with fence on top of this to the rear. It has dappled shade in the morning but then full shade all afternoon. Clay soil. What plants would do well there? Would like a mix so colour through the seasons. Am not a keen gardener so would prefer ones that require very little maintenance (I wouldn't want to put in annuals or bedding plants). Any suggestions? 