Question
I need my rose bush to bloom again in late June. Is there a way to encourage
this?

Answer
A quick lesson about roses and their flowering habits. All roses go through a cycle of making a flower. It starts with them growing their canes, then their leaves and finally  their buds. All these cycles need nitrogen, but the blooming cycle needs phosphorous, that is the middle number in fertilizers. However these productions take up a certain time and forcing them is tricky. Often the weather won't co-operate with you.  It usually takes about 3 to 4 weeks between flowering flushes so you can roughly figure out how long for the next one. You either want to activate or slow the rose bush down. Because you have said that the rose has already bloomed, I will assume you are in a warm area. Try using a tomato fertilizer as it is geared to make flowers and the phosphorous is high in it. Only use it one time. It would be ideal to keep the rose out of the hot sun  because fertilizer can burn in high heat and also sun puts roses under stress and you want it to bloom.  Simply throw some sort of cloth or make a protection of Remay cloth. Roses only need 6 hours of full sun to do well and as the plant has lots of new growth which is tender, it can burn under high heat. Now having said all that, it does take more than a couple of weeks to make rose blooms but you may be able to at least get some buds and flowers in late June.  Having said all that the only problem I can see is that it will bloom before the  end of June if the weather is warm. Gardeners who exhibit go through all sorts of hoops to make sure they have the perfect rose for the show and it isn't easy.