Day lily not flowering
After moving into our house almost two years ago, we were given a number of plants from my parents, including a clump of day lilies. They grow brilliantly in my parents garden in Cardiff, but this is the second summer they've been in our garden (in north London) and we haven't had any flowers since planting them. They are in a sunny spot in our north facing garden, near some crocosmia and a spirea that both do well. Apart from the odd hole caused by slugs in one or two leaves, they look healthy. Can anyone offer an explanation or suggestions?