On May 12, 2022, Lucille1 from Cochranville, PA wrote:
Corydalis incisa is a nightmare- incredibly invasive, and can form a carpet of weeds that choke out any native or precious plants around it.
I spent another 6 weeks,from mid-March to 1st week of May, hand-pulling masses of this plant that invaded the stream bottom down the hill, 70 yards from where the first plant invaded 5 years ago.
If you have this plant, you must remove it in early spring, before the seed heads ripen and explosively spread seeds a meter in all directions. It is biannual, so if you don't dig or pull out the other hundreds of little baby plants that grow from tiny bulbs this season, they will become the big, v... read more
On May 25, 2016, SherryBikesDC from Washington, DC wrote:
This plant is considered invasive and a threat to native species in the US. Please don't plant it in your garden. Here's a link to the source material on this. http://blogs.nybg.org/science-talk/tag/corydalis-incisa/
We found it in one of our garden beds in DC two years ago, and it spread very quickly. We've managed to weed it all out, and have to be diligent about pulling it out every spring.
There are corydalis species that are native to the US. Plant one of those instead.