Cultural tips for all roses:
You might want to try using alfalfa tea on your roses. Alfalfa releases tricontanol, an alcohol ester compound that acts as a growth stimulant. The alfalfa is not a food in the sense that nitrogen is, but it makes the uptake of nutrients more efficient. You'll have a dramatic increase in both growth, bloom, and overall vigour of the plant.
2 cups Alfalfa pellets or meal.
Apply about a half gallon on your minis and a full gallon on your larger bushes about every 6-8 weeks. This is something that can be done in the garden at any time of the year without the usual concern of stimulating growth at inappropriate times, as you would with fertilizers.