First garden diary. I keep thinking of doing one, but never do. So today I decided to actually take a little time and do a quick one.
Some nasty moth caterpillars have invaded our iris bed. They've probably been feasting on the rhizomes for years but we only just now realized that was why they weren't flowering much in recent years. We had assumed they were just too crowded, which I'm sure has also been a problem.
more below the squiggle-de-gibbet
First off, let me say that I am not good at the follow through. If my husband doesn't take an active role in the maintaining of our flower gardens, things go to shit. I water, I mow, I take care of my pond, but the flowers get neglected. This year, my husband has been active and dug out some new flowerbeds and cleaned up the old. Among the old, was an area with bearded irises. I have not tidied the foliage on those for years. As such, we discovered that a common iris pest has invaded. Lepidoptera. A brown moth caterpillar that bores into the rhizomes.
Here are a few pictures of the damage they do to the rhizomes:
The moths emerge in late August and September, mate and then lay their eggs on the foliage of the iris. The eggs overwinter and hatch the following spring, where the larvae then work their way down the foliage to dirt level and burrow into the rhizomes. They grow and burrow until late July/early August and repeat the cycle of emerging, mating and laying eggs.
Our patch of iris was pretty much decimated due to my laziness, neglecting to cut back the foliage in the fall (we also should have been separating them every few years). So we dug them up, cut off the bad parts of the rhizomes, and I filled a bin with water and submerged the salvaged plants. I let them soak overnight to drown any borers that may have still been in some of the rhizomes. Lo and behold several floated to the surface.
I then scooped them out and lay them on a tarp to dry out. The plants not the borers. lol
After I scooped out the salvaged plants, I took the non-salvageable ones and plopped them into the bin of water as well, to kill any borers still in those so that they wouldn't be able to mate and lay eggs on our iris all over again. After they soaked a while I scooped those to put in our compost pile and then dumped the water. Here are a few of the borers:
freshly drowned moth caterpillars, a.k.a. iris borers
Next step, replanting the iris after I finish tilling and cleaning up that section of the flowerbed and vowing to myself to cut back the foliage every fall and keep a closer eye on them in the spring:
Iris site, half-ass tilled
We probably won't have many, if any, of these flower next year. So we may buy some new varieties to add until the younger plants we salvaged have time to grow and start blooming again.
An iris bloom from a few years ago.