Roses are prone to picking up fungal marks on their leaves, especially in damp or humid weather, and the instinct for many gardeners is to reach straight for something in a bottle. Simply removing the affected leaves by hand, however, deals with much of the problem without needing to spray anything at all.
Leaves showing dark spots or a dusty, pale coating are best picked off as soon as they are noticed, rather than left to spread the problem further along the stem or onto neighbouring leaves. Dropping the affected leaves straight into a bag rather than onto the soil beneath the rose helps stop spores from simply settling back into the same bed.
Airflow matters as much as removal
Roses planted too closely together, or surrounded by other dense growth, tend to suffer more from these leaf problems, since damp air lingers around the foliage for longer after rain or watering. Thinning out crowded growth from the centre of the plant allows air to move through more freely, helping leaves dry out faster and making the whole plant less inviting to fungal problems generally.
Watering at the base of the rose rather than over the leaves also makes a noticeable difference, since wet foliage left standing overnight is far more likely to develop marks than foliage that stays dry. A morning watering routine, rather than an evening one, gives leaves plenty of time to dry out before the cooler, damper hours of the night set in.
None of these habits will make a rose entirely immune to the occasional spotted leaf, but together they keep the problem manageable without reaching for a spray. A rose tended this way, with fallen and affected leaves removed regularly, usually copes perfectly well through even a particularly damp summer.
Fallen or removed leaves are generally best kept out of the compost heap altogether, since the same spores that caused the trouble in the first place can otherwise survive and eventually find their way back onto the roses the following year.
