Attack of the Hibiscus Sawfly
Hibiscus Crown Jewels.
I owe my hibiscus an apology. Not my hibiscus syriacus, the nearly indestructible Rose of Sharon that is still churning out flowers daily, but my perennial hibiscus “Crown Jewels,” which seems to have been eaten alive while my back was turned.
Perennial hibiscus, sometimes called rose mallow, is a native plant that is all the rage these days. The most popular varieties have dinner-plate-size blooms in shades of red, hot pink, and white, but these are not my favorites. To me, they look fake, almost freakish, the accidental outcome of a bolt of lightning and an ill-timed electrical current. “Crown Jewels” is more demure. It has pretty dark foliage and blooms that measure a paltry 6 inches across - large enough to make a statement but not garish. The flowers (which, like all hibiscus, last for only a day but appear throughout the summer) are white with a red center, and make a nice contrast with the blue Rose of Sharon and bog sage nearby.
Best of all, “Crown Jewels” likes its days hot and its soil soggy. As such, it seemed the perfect plant to help transform my swampy back yard into something resembling a garden. I had no intention of tromping about in the mud coddling sensitive plants that probably wouldn’t survive anyway, so I made sure to select only tough plants that were suited to the conditions. Let nature take its course, I said. And that’s exactly what it did.
I suppose I was lulled into a false sense of security by the fact that “Crown Jewels” was a.) native, b.) appropriately sited (sunny, wet), and c.) blooming regularly. Being behind mountains of bog sage and rather hard to reach did not help either. Passing by each day, I did notice that the leaves were being eaten, but I can live with a few chewed leaves. Trusting to items a., b., and c. above, I did nothing. Now my hibiscus is a skeleton.
Belatedly, I hit the books and identified the culprit as the dreaded hibiscus sawfly, a common and all-too prolific pest of plants in this family. Suggested solutions ranged from hand-picking and squishing (no thank you) to installing a bluebird house in the yard (on my to-do list, but not something that will help me today). Regularly spraying the underside of the leaves with insecticidal soap sounded more reasonable, but would be of no use now that the proverbial horse has left the proverbial barn. Even reaching for a bottle of the hard stuff (which I admit I keep on hand in case of plant emergencies) would do no good. All I can do is cut it back – way, way back - and I’m heading out now to do just that. Next year I’ll do better.
8/14/2013 07:37:12 am
Hi, my heart goes out to you because this year I got hit with the same problem on my beloved hibiscus (looks exactly like yours, pure skeleton.) I was so upset because it is definitely my favorite to watch over the summer. I don't know if you got hit with this again this year or not, but I read to cover the leaves and surrounding ground area with flour (it dries out the worms) then rinse it off after 24 hours. I just doused my plants (it's huge by the way, about 4' X 5'.) Here's hoping!
8/14/2013 07:58:22 am
Thanks so much for visiting, Lynn, and I'm sorry to hear about your hibiscus. Yup, I had the same problem this year, in spite of taking some preventive measures (Neem and diatomaceous earth, which I think is like the flour idea). I am pretty discouraged at this point. My next step is to move it to a better (i.e., easier to access) spot so I can keep better tabs on it. If that doesn't work, I think I may have to break up with it. Good luck with yours!
8/16/2013 05:20:13 pm
I try to hew as close as possible to a no-spray garden.
8/17/2013 01:16:15 am
I've heard they were working on a sawfly resistant hibiscus. In fact, the new Plant Delights catalogue is hawking one that looks quite beautiful. I am always a bit skeptical of these promises, though. The pests don't read and always seem to miss the news that they're eating something they aren't supposed to like.
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The Galloping Horse Gardener is a native New Yorker who packed it in in 2005 to live under the radar in Cary, North Carolina. In 2014, she removed to a new secure location somewhere in Raleigh.
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