Galls on my Shrub Redleaf rose bush by Kelli Barker

Photo:  CMG Kelli Barker

Nature spared no creativity in designing its myriad of galls!  As I’ve dived deeper into my master gardener apprenticeship, I’m paying closer attention to the variety of shapes, sizes and colors of galls on various plants. Despite my increased awareness, I was still stumped in identifying what looked like large coronovirus molecules had attached themselves to my Redleaf rose bush (Rosa rubrifolia) in late May.  I planted this xeric shrub in northwest corner of my front yard, just 6 or so feet from the main road of my house in Wheat Ridge.  

While it’s been slow to grow and thrive, I’ve enjoyed watching the deep green/purple leaf backdrop against the single petal pastel pink flowers in June as deep orange-red rose hips in summer and fall.  They grow 6-8 feet tall and 4-6 feet wide.  Moderate to xeric water needs.   

Photo:  CMG Kelli Barker

During my first help desk training, my fellow apprentices and mentor helped to identify these as Rose Gall Wasps. In doing the research into these odd shapes, we turned to Insects & Diseases of Woody Plants in Colorado (CSU Extension, 2014). 

This Plant Select plant apparently is no stranger to these gall insects and can be a fairly common. Thankfully, I also learned that little plant injury comes from these galls despite their curious and threatening appearance. The galls have not returned after pruning them off now that the rain has slowed and the heat has increased. Now to my bigger challenge of keeping this little guy alive!

Plant Select information on Redleaf rose (Rosa glauca, R. rubrifolia): 

https://plantselect.org/plant/rosa-glauca-r-rubrifolia/

For additional information on insect and mite galls:  https://extension.colostate.edu/topic-areas/insects/insect-and-mite-galls-5-577/