This year pear trees in southern Ontario were hit hard by Pear Trellis Rust (fungus, Gymnosporangium sabinae). Attractive as these orange spots are initially, after seeing the juxtaposition against the green leaf of my Flemish Beauty pear tree, my heart sank. It was just a matter of time before the pretty orange spot transforms into a spore-spewing protrusion.
The wet windy spring had transferred the overwintering spores on junipers (the winter host) to my pear (summer host). And it just wasn’t me that had it. I noticed the espaliered ornamental pears at Chappell house (Riverwood Conservancy) also had the “measles.” While volunteering as a Master Gardener at the CNE fair, a quarter of the questions were about pear trellis rust.
Tweets from Voice Of Tree Care on #treechat confirmed there’s not much you can do once the pear tree has the disease (especially with Ontario’s cosmetic pesticide ban, which I support btw). “Don’t let the leaves overwinter,” Amy stressed, “Prevent spreading the disease, pick up the leaves and burn them.” Or put them in a garbage bag since we can’t burn leaves in urban areas.
So, pear leaves with pear trellis rust are a definite no-no for leaf compost or leaf mulch. This is what I mean about guarding your transitions. Nature will guarantee you a pile of misery if you are lazy, forgetful or complacent. HA!