I like it too. It loves nooks and crannies in walls. We see it all over town where I live. You can see a bit of Campanula portenschlagiana on the right. They love the same conditions. Is it evergreen for you Rouge? It is here.

That is a particularly floriferous specimen flora_uk!

Ours is evergreen until it goes all mush with continued below zero temps.

The white one works better in my garden

Thanks so much for this reminder 'woody'! When I first saw this white one (ochroleuca?) at your place I made a mental note to plant a couple and I forgot about this till just now.

They are really easily transplanted as seedlings. I have lots of seedling...! I should have sent some home with you when you were last here. If you can't find them elsewhere, rouge, you know where to come...:-)

Campanula - they are almost evergreen here, but not quite. They are one of the last things to go to go brown and one of the first to green up in spring. This past dry, cold winter was hard on them and most of what is in the garden at the moment started as seedlings.

"It looks so delicate but you gotta be impressed by its toughness....if
you have one in your garden it will find its way all over your
property...in often the most unlikely locations. So yes does it seed all
over but it is trivial to remove it. (And it gives that satisfying
sound when you yank it from the ground indicating that you got it all
;))."

Yep, I have it all over the garden, coming out of cracks in concrete walls, along edges of paths, every where. I just pull where I don't want it. It's a good little workhorse and blooms for such a long time.

Annette

Brought some Corydalis ochroleuca (white/pale corydalis) back from Victoria B.C. but it didn't survive in our garden. Further to Woody's success with it, it's one of the only three (I think) original plants to have survived from Jekyll's time in her former (now recreated) garden at Upton Grey, UK.

As said, Corydalis lutea (golden/yellow) corydalis is very easy to remove; very easy to pull up or raked away. This is related to it growing from a fleshy root, not a corm, as with corydalis like C. solida. It certainly does have an incredibly long bloom time for a garden perennial.

Had problems with C. cheilanthifolia (fern-leaf corydalis). Held it in a pot for a few months in my plant preparation area; that was until I read warnings about it. Still pulling out a few seedlings yearly and the plant was disposed of about ten years ago.

Have had no problems dealing with the gentle seeding of C. lutea

I love it here! It's the first to flower and last to succumb to winter, not evergreen here. It's spreads where it is happy. It's the best filler! Better than mulch any day

And I also see your nice 'bits and pieces' of wonderful Painter's Palette !

I love the c. lutea, just watch out for corydalis incisa, or purple keman. I saw something like it in a nursery, but managed to keep my plant aquision disorder in check. Imagine my joy when I saw that the same plant, or something that looked like it, had volunteered just to the right of my greenhouse door! Karma ... the universe was rewarding me for exercising some self-discipline! The next year, it was growing vigorously and blooming all along that end of the small greenhouse. This year - in late March - it was growing and blooming all along that east end of the greenhouse and around the corner halfway down the south side. It had also hopped from the east side across the path to blanket the area around the compost pile and surround my potting bench, spreading around the corner of the rose bed, from whence it hopped across towards the vegetable garden which it was beginning to encircle. Time to do a little research:

http://blogs.nybg.org/science-talk/2014/07/detecting-an-invasive-plant-before-its-too-late/

As difficult as it is to pull blooming things in March, especially these delicate flowers and leaves, I pulled out all that I could, enough to fill a 5-gallon bucket (compressed) and then some. What I couldn't pull, I cut to the ground so it wouldn't have a chance to set seed.

I'll be keeping an eye out for more volunteers next year, and this year continue to battle the non-native terrestrial orchids - when one sees volunteers growing equally well in moist, humus-rich shade as well as crushed bluestone over nutritionally deficient native sand in full sun, one gets suspicious and looks it up.

This plant has been on my wish list for so long! I ordered seeds last year but they were not viable. I guess the seeds have a very short shelf life. I never see the plant at any of the nurseries. I may have to try and order the plant online. Enjoyed the pictures!

I was on a garden tour today and I saw a spectacular "mass planting" of CL.

As they do so well they were growing out of the joints in a dry stone wall, beautifully cascading.

UPDATE (2017):

When visiting 'woody' earlier this season she was kind enough to send me home with a sample of ochroleuca (I never see it offered for sale). As probably expected it has thrived and I am looking forward to the white flowers...a nice change from the yellow of lutea.

('woody', I got the impression from you that it doesn't flower as consistently as does lutea which basically has blooms from spring to first frost).

The white one does have a peak bloom period in early summer, with more sporadic flowers before and after the peak period. It is almost evergreen here and is one of the first things to bloom in spring and one of the last things to still have fresh blooms in late fall.