At one end of my backyard are three large, old rosebushes. They grew from cuttings taken from my mother’s childhood farm more than half a century ago, and the bush from which they were taken had persevered on the hot, dusty South Dakota prairie since the 1930s. My mother recalls that it grew up over the gate in the yard, covered with needle-like thorns, and her mother was always after her dad to trim it back. But having just come through the Dust Bowl, where the entire farmstead was reduced to lifeless dirt, John Welsh could never bring himself to cut away any living greenery.
That original bush’s progeny, transplanted to central Minnesota, has been largely untended since 1960 – in part because I, like my grandpa, find it hard to cut back anything alive. Mostly, though, it’s because the cluster of bushes has grown into a monster, akin to the fortress of thorns that surrounded Sleeping Beauty’s castle in the old fairytale.
They are not a fancy hybrid – just a plain, old-fashioned shrub variety that flowers prolifically early each summer with yellow blooms for a week or so, then subsides into foliage and thorns for the rest of the season. They possess the hardiness of old, native varieties, seldom troubled by disease even when my showier roses are shriveled and mottled by black spot, rust, powdery mildew or any of the many other pestilences that reduce the rose gardener to fits of tears and profanity.
These roses, however, do have one perennial nemesis. Every year at this time, the leaves of the bushes start to brown and curl at the edges. A close examination reveals the leaves to be skeletonized. Left unchecked, the bushes are largely denuded of foliage by the end of June, only to sprout new, leafy growth again in July.
For an astonishingly long time, I couldn’t figure out what was going on. Perhaps I’m profoundly unobservant, or more likely I never cared to venture within range of those vicious thorns. When I finally did take a closer look several years ago, in the midst of the spring die-off, I discovered an invader. The leaves were covered with small, green worms. The Internet quickly ID’d them as rose slug sawfly larva, destined to become a fairly benign little winged insect. There are three varieties of sawfly larva that affect roses in my area: the bristly roseslug, Cladius difformis; the European roseslug, Endelomyia aethiops, and the curled roseslug sawfly, Allantus cinctus. I seem to have escaped the bristly roseslug. The other two are happy consumers of my bushes.
There is apparently no effective remedy for these pests, according to the experts. I avoid chemicals in the garden (save the bees!), and the recommended treatment, powerful blasts from the garden hose, tend to knock off the blossoms as well – but their blooming period is brief enough, and is the only thing that makes them worth keeping around. The only other recourse is to pick them off the leaves, one by one. And so, rose worm pickin’ season begins.
I used to be more squeamish about such things, and began by scraping them off leaves and onto the ground with sticks (inefficient) or picking them off with tweezers (messy). Finally, I got over the willies and started picking them off by hand. I find it most effective to gently roll them between my thumb and index finger, which dislodges them without mushing them into green jelly.
In a previous post, I confessed my aversion to killing just about anything (mosquitoes are an exception). This includes little green worms. So when I pick them off the leaves, I drop them a few feet away from the bush and watch them begin at once to creep back toward their source of sustenance. I suppose most of them perish of fatigue and/or starvation before they reach the bush again, so it would perhaps be kinder to simply squoosh them or drop them into a can of kerosene. Yet I cannot bring myself to be the active and immediate agent of their demise … and there is always the possibility that they will survive to fulfill their destiny as winged creatures with sharp-toothed vaginas (it’s possible my understanding of sawfly anatomy isn’t entirely clear).
I have so far offered this sporting chance to several hundred sawfly larvae over the past week. Like the flush of starry blossoms, rose worm pickin’ season is a brief one; in a few days it will be all over. Then what will I do with my time? No worries: aphid pickin’ season starts next week!