I’m willing to bet that whoever said ‘life is not always a bed of roses’, from time to time experienced a few problems with her rose beds.   Case in point, a friend of mine called for some advice about his roses. As he described the bronzing of the foliage, distorted buds and leaves, I surmised that his roses were playing host to spider mites.   You see, mites thrive in hot, dry and dusty conditions.

How can you tell if you have mites on your roses? Well this particular task may require you to play the role of Sherlock Holmes.  You’ll need a keen eye and a magnifying glass, as spider mites are quite tiny, about the size of the full-stop at the end of this sentence. Young mites are greenish-white, while older mites are reddish-brown.  Inspect the underside of leaves for black or brown flecks resembling dust.  If you see suspicious signs, tap the leaf on a piece of plain white paper.  If you see spots moving then you probably have spider mites. As the name suggests, mites are not insects but arachnids, related to ticks and spiders, so you’re looking for eight legs, not six.

Common symptoms of mite infestation are  bronze discoloration on the upper surface of leaves and fine webbing on the underside.   Discoloration starts from the leaf tips,  with leaves bleaching out, drying and finally dropping.  Look out also for  shortened internodes and petioles,  twisted or distorted new growth,  and failure to bloom.

To defend against mites, maintain a regular feeding  and watering programme, one that results in healthy vigorous rose bushes.  Inspect the underside of leaves regularly, and at the first sign of mites or aphids, apply the  “water blast” technique.  Simply direct a blast of water to the underside of leaves every 7-10 days. This action knocks mites off leaves and destroys webs.

A high population of mites in your garden may indicate a low population of the mites’ natural enemies, such as lacewing and  ladybird beetle. Natural enemies of mites often fall victim to insecticides used to kill other pests.  To rid your garden of  mites (as well as aphids and scales) without decimating  the population of  natural enemies, try using organic treatments such as insecticidal soap, horticultural oil and neem oil, every 7-10 days.  However, if more stringent action is required, it is best to contact the experts at RADA or your garden centre.   I have found the group of biological miticide/insecticide  containing abamectin (e.g, Cure, New Mectin) to be relatively safe and effective. 

Of course, if you have not destroyed the population of ‘good bugs’, your rose bushes will likely recover just fine by themselves,  as soon as the dry season ends.   Which would mean that life can indeed be a bed of roses!