I have six rose plants in my garden. All those six rose plants were bought at same time three years back. All of them are grafted. All receive good sun light, planted in same soil. Three of them are flowering for the past three years. Other three were not flowering right from the start except for the single rose that was present on the plants when I bought them. They have long unbranched shoots that grows from the original stem. Each plant has about 4-6 of those long non flowering branches. They doesn't flower, doesn't branch, and also doesn't stop growing. No matter how hard I prune them, they always give same non flowering shoots. If not pruned, the branches grow even upto a metre and a half long, unbranched. But still no flowers. What might be the reason? What can I do to make them flower? Bcoz my mom won't let me put new plants in their place...