It is no secret that roses have long enjoyed the honor of probably being the best-loved flower in our gardens. So, I’m sure that many of you have already discovered the advantages of incorporating your beloved roses with clematis. I too adore my roses, but the last two years I have had a few roses that were brutally assaulted (okay I am exaggerating slightly) by rose leafhoppers. I confess I hate the look of white stippled markings and the somewhat anemic leaves caused by their ravenous feeding. I read that they actually have a name for this damage: “hopperburn”.
It is possible that you may even have them lurking in your garden and not even know it, so I’ve included pictures of a rose leafhopper nymph and the harm that is caused after they have partaken in the rose leaves’ nutrients (chlorophyll). I’m always stunned by how something so small can wreak so much havoc in the garden. It should be noted that the injury inflicted upon the top side of a rose leaf by these pest looks very similar in appearance to the damage that occurs from a spider mites’ feeding. However, spider mites are usually more problematic in the dry summer months and they leave their telltale calling card of fine webbing.
Fortunately, unless the infestation is overwhelming, the attack of these sap-suckers causes mostly aesthetic harm. The prudent thing to do is to ignore them which is what I normally do. In my garden I try my best to accept that Mother Nature is not perfect, so there will be holes, brown and blemished leaves, etc. It is only when things seem a little lopsided that I think about retaliating against the enemy. Even though I would like to nuke my garden’s foes, I’m usually reluctant to spray as my first course of action since I’m afraid of harming any beneficial insects. So, this year I’m going to try a new tactic which is to give my roses that show any sign of damage an invigorating shower. My plan is to unleash a tsunami spray from my garden hose directed at the undersides of the leaves and try to dislodge as many of these offenders as I can. My hope is that by starting early this year my new aquatic approach will keep them at bay. If that fails and their population grows to where they inflict more damage than they did last year, I will, as a last resort, go to Plan B and blast them (o.k., spot treat) with insecticidal soap or narrow-range oil.
The Silver Lining behind all this is that rose leafhoppers are a host specific insect (meaning they dine solely on rose leaves), so I am happy to report that they haven’t bothered my babies (aka clematis) that are co-mingling with my climbing roses.
For a look at the life cycle of the rose leafhopper visit: http://jenny.tfrec.wsu.edu/opm/displaySpecies.php?pn=370