The autumn months of September and October are when roses perform at their peak. After faithfully following proper rose procedures up to this point, now — at last — you should begin to reap the rewards of full, vibrant, glorious blooms.
Your work isn’t quite done yet, however. Although autumn is the best growing time, it’s also the time you must prepare your rose bushes for winter coming onslaught.
Producing those beautiful blooms you are so proud of is hard work — for your rose bushes, too. They need a lot of water to fuel the flowering process. Continue to water them deeply, as often as needed to maintain growth. Watering daily is okay if you are showing them off, just be careful and observe closely so that you do not over-do the watering process. You want beautiful blooms, not drowned roots.
Continue using water-soluble compost through the end of September. Consider a commercial bloom-boosting fertilizer. The large number in the middle of the formulation is your cue — nitogen, PHOSPHORUS, potasium (potash).
Black spot and mildew are dangerous because conditions for their growth are ideal, so keep up with a...