A recurring theme in the garden (and in life, I suppose), is that things do not always turn out as you want, or expect. My best guess is that more works out for the better than the worse, and often the bad is not so horrible, just disappointing.
Unhappily, the weedy yellow flag iris (Iris pseudacrous, above) has invaded further into spaces between boulders in the koi pond to crowd out less vigorous, but highly regarded Japanese irises (Iris ensata, below). The aggressive, yellow flowered irises were planted in a bluestone gravel filtration area of the pond, which seemed like a good idea at the time, but long ago was acknowledged as folly. Fortunately, the invasive iris is safely enclosed in the koi pond’s closed system, so it does not escape into surrounding wetlands, but it has become a lovely nuisance.
The flowers are a delight, but I figured it would spread from rhizomes, which it does, and these could be successfully managed. While it didn’t happen overnight, I failed to anticipate that yellow flag would also spread its seed to every spot of soil or gravel in shallow water, and particularly that it would inflict harm upon the more colorful and treasured Japanese irises. If the project was feasible, yellow flag would be long gone, but I’ve given up hope that it’s possible to extricate the good from the bad irises without more effort than I’m capable of.
Interestingly, on dry ground in the garden, more than once I’ve seen innocent, ordinary plants crowd out ones reputed to be overly aggressive. Seedlings of ‘Espresso’ geranium (Geranium maculatum ‘Espresso’, above) have overwhelmed what had been a spreading patch of Cypress spurge (Euphorbia cyparissias), and in the koi pond variegated Sweetflag (Acorus calamus ‘Variegatus’, below) has pushed yellow flag into a corner, half the space it occupied a few years ago. This is of no help to Japanese irises on the far side of the pond, but at the least there will not be only yellow flags surrounding the pond.
There’s thinking too little, which I am often guilty of (if you ask my wife), but also too much, and while I did not think through the planting of yellow flag to filter the koi pond, I delayed planting Chinese ground orchids (Bletilla striata, below) for too many years, overthinking, presuming it would be too delicate for my often negligent care. In fact, a few failed to thrive in damp or shaded spots, but where they’ve taken, they’re far from delicate. In one area, a gold leafed carex flops onto the thriving clump of orchids that has spread from a few tiny plants to several dozen in only a few years. I like the carex, but not that much, and there’s no doubt that orchids are favored if it comes down to one or the other. And, unlike the yellow flags, I can get at the grass to dig it out.