Give them time to settle in. Some gardeners use a granular fertilizer that becomes available to the plants when the soil warms. Others use this as well as organics. And, of course, others use only organics. Don't forget to water.
Many gardeners apply Epsom salt, which contains magnesium and sulfur, after they have pruned.
They've found it encourages lush growth and pretty flowers. Place a 3-inch layer of organic mulch around your roses to discourage weeds, help maintain soil moisture and add nutrients as it breaks down. Valentine's Day is the traditional reminder to prune modern hybrid roses. You will remove old canes that no longer produce good growth and any branches that cross at the plant's center. Prune out weak stems.