I have asked this question to many people and nurseries. I have older and new roses that bloom beautiful in spring and that's it, I fertilize spay and everything. I have others that do OK. The only thing I can think of, some of roses are effectived by overhead water spray from the lawns which are water twice daily. Can you assist. Thank you, Lawrence Moglia
I'm not sure what your question is. If it is failure to rebloom, then one questions whether they are getting enough sun (6 hours minimum), enough water, or whether they are over-fertilized, producing green growth at the expense of flowers. I assume you have vigilantly checked for small insects like aphids, spider mites and white flies where flower buds form. You say you are spraying - is this for black spot? What are you using? Certainly an infestation/infection will reduce bloom. Watering deeply and at soil level is recommended. Watering leaves twice daily is a set-up for leaf diseases of all sorts. Do you perform annual pruning to "open up" the rose to sunlight and to spur young growth. Canes lose vigor as they age and bloom less than younger wood. Finally, are you sure these are reblooming roses? Some old garden roses and climbers do not. If it seems that all the above check out as OK, then get a soil test. It is possible to have toxic levels of nutrients as well as severe deficiencies of micronutrients.