Wood Poppy or Celandine poppy come up very well by self sown seeds without being invasive.
Bloom: Spring & Summer
Woodland poppies are a native plant, apparently growing naturally in the mid west, Ohio, MO.
Here in GA they grow very easily, self seeding like mad. This wasnít particularly noticeable until this year after 10 years in the garden. In this area, I pull the winter weeds in Feb. & put down woodchips. the celandine poppy seedlings donít come up until March-April. I only saw the occasional welcome new plant as the mulch was smothering them out.
I added them to a new garden last year & didnít get back to weed & mulch till the end of April, & there were nice patches of new seedlings. I chose not to mulch that garden, the celandines will make a very effective ground cover when they get their growth in a couple months.