Am sure that I've already commented on the problems with your roses - elsewhere and although I very much agree with everything that has already been said - in that roses require fairly moist soil and being heavy feeders need plenty of potassium rich fertilizer from early spring onwards - if you are to have a prolific display of blooms - am not really 100% sure - that it is just more water that your roses require or that it is a disease that your roses are suffering from.
As apart from looking as though they could do with pruning - think because the patchy problems on the leaves doesn't appear to be universal on the plants - that the cause is possibly more to do with scorching - which as I grow roses in a hot climate where summer temperatures often exceed 40 -45 C or 104 - 115 F have found can be caused by the fluctuating temperatures of late winter and early spring - as well as by moisture sitting on the leaves as the sun comes up or even from being sprayed by a passing tomcat.
With regard as to the best time to water or spray your roses - the best time would be early morning before the sun is up - and is of particular importance when it comes to roses - as they are prone to so many different diseases but are especially prone to powdery mildew - which as watering in the evening - is known to make all plants more susceptible to these problems and very definitely powdery mildew - due to the fact that excess water remains on the foliage and around the plant overnight - giving bugs and disease the ideal damp conditions they need in which to thrive - it is always better to water in the morning rather than in the evening.
As for help with organic fertilizers - again I would agree with everything that has already been said - but would just like to add - that as I know many people who grow prize winning roses - who swear banana peels are the best rose fertilizer they've ever used - because they contain a high amount of potassium and of course are free - if you eat a lot of them

So as you are interested in looking for organic ways to feed your roses and as this appears to be a very popular way of feeding roses amongst the organic rose growers - think that you will find that there is a lot of very helpful information on this subject - in the threads entitled " Save your banana peels for your plants " which you will find under the heading " Recycling and Composting " as well as " Bananas for your roses " which you will find under the " Rose " heading - both of which contain many organic ways of fertilizing not just roses - but many other plants too.
