I don't like the yellow one but I do have - and love - the white stuff. It does indeed bloom all season. It's almost evergreen here and is in bloom already! It blooms well into November. It seeds like mad but is realitvely easy to pull out if it goes where you don't want it.

Corydalis ochroleuca. Grew it in my old garden. Not a long lived plant at all but reseeded freely. It did bloom sporadically throughout the growing season but I'd not consider it all that long-blooming, in that it would bloom, stop blooming then rebloom again. As I said, sporadically :-)

I still list Erysimum 'Bowle's Mauve' as the longest blooming perennial. In my area, that plant will be in bloom virtually year round, only shutting down in midwinter.

I don't know how any Corydalis could bloom longer than the yellow (lutea)? In my garden it virtually never stops blooming unless it gets really dry and really hot.

I added the white last year and it did throw out a few blooms, but nothing like the yellow. Hopefully it will do better this year. It also seemed to be an extremely slow grower, but maybe because it was its first year in my garden.

I just came in from the garden a few minutes ago where I was examining the white. Again, it seems really slow to take off. The yellow has been blooming for a couple of weeks already, but not a sign of anything on the white.

Kevin

The yellow corydalis certainly is vigorous, but I find the yellow color on it very harsh and prefer the more subtle white. It certainly blooms more vigorously at some times than others. This is what it looks like as of 5 minutes ago looking out the office window into the south side of the backyard:
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This is more or less the same view at the end of May last year:
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Here it is with a 'Butterfly' Japanese maple in July:
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I can't seem to find any fall pictures of it but you can see from this picture on December 29 2011 that it was still green:
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Thanks all! Woodyoak - your photos have convinced me to search for some, although I certainly don't have a scenic property like yours! But we do have snow!
Jan

JanOn wrote: your photos have convinced me to search for some

Jan, I am not sure where you reside but the 'famous' LOST HORIZONS in Acton has it and many other corydalis.

Here is a link that might be useful: White corydalis here

Thanks for that rouge 21. I live in London, so Acton is certainly do-able for a road trip, and the pictures in their gallery could convince me to have a closer look!
Jan

Lost Horizons is certainly worth a visit! They have some nice display gardens and a good selection of interesting plants. I just checked Canning Perennials - which is closer to you - to see if they have it. It's not listed in their on-line catalog but perhaps it might be worth calling them to see if they have it/can get it for you. Have you been there? It's on my list of nurseries I'd like to visit. I gather they have quite a nice display garden too.

For what it's worth... in my experiece the white corydalis transplants best as seedlings/small plants. So, when you're buying one, don't buy the biggest one; buy something small. Is there a local Horticultural Society near you that has a plant sale? Maybe it would be worth contacting them to see if a member might have them and we willing to either provide you some seedlings or make them available through the plant sale. I have provided plants in the past to our local Hort. Soc. plant sale. If you lived closer, I could provide you some :-)

woodyoak that is beautiful! I have the yellow, but your white color looks softer and more pleasing.

Woodyoak -- Canning Perennials (according to their website) no longer operates a retail store but has gone to a totally online business. You can still pick up an order by appointment or on designated days, but I guess this means they no longer have their lovely display gardens.
Canadale Nursery in St. Thomas is another favourite that is a great excuse for an outing -- they have probably the best selection of perennials in the area. Maybe even white corydalis!
Jan

Jan - that vaguely rings a bell re Canning - I guess I missed the opportunity for a visit to it :-( I have ordered from them on-line in the past.

Do you think that Woodyoak's plant is Corydalis ochroleuca? The photographs I see on-line of this species show white flowers with some yellow and/or green. And the descriptions are that it's an evergreen plant that self-sows and has a long bloom time. Are there any other white corydalis that bloom a long time?

Yes, mine is supposed to be ochroleuca. I'm not aware of any other white one - but maybe there is one...? There is a little bit of yellow in some of the flowers if you look close, but it's not very visible.

Edited to ask..... Kevin - did your white ones eventually start performing for you? What I have found is they transplant best as seedlings - a big robust-looking plant generally keels over shortly after transplanting but seedlings of 1-3" or so do well (especially if you've dug up a trowel-full of earth with them that probably has seeds in it too....) So, for anyone looking to buy one of these, buy the smallest plants, not the largest ones.

This post was edited by woodyoak on Fri, Apr 4, 14 at 13:46

Since this is an older thread, I'll have to back-track a bit.

My original ochroleuca did not reappear last spring. It was a goner, but seedlings did appear by the hundreds. Unfortunately, I never got around to thinning them (big mistake), so by the time I knew they were growing too thick, it was almost too late to do anything about it. I just let them be. By midsummer, that bed was almost weed-like with the number of plants growing on top of each other. They did bloom however, just later.

I haven't been out in the garden yet, but I thought I saw some green poking through the other day looking out the window. Now it's all buried again with 10 inches of snow from last night.

If I remember correctly, ochroleuca seems to bloom a bit later for me than lutea, but once it starts, it keeps going until frost.

Kevin

Hmmm... Kevin, it sounds like you like your plants to stay neatly in defined spaces :-). White corydalis is definitely more of a sort of tall groundcover for me! It doesn't seem to overwhelm/choke out other things so makes a good filler - but if you don't want it in an area you do indeed need to be vigilant about removing seedlings! Fortunately the seedlings are easy to remove by yanking handfuls as they appear :-) It grows well in the very dry, shady conditions under the roof overhang on the north side of the house so it is particularly valued there.

The "little bit of yellow" you mention makes me laugh in light of your recent post about being rather anti-yellow in the garden. I was just mulling over whether I could "live with" that little bit of yellow and then realized that I had gone to sleep thinking about putting in some pale yellow columbines in the area that I want the white corydalis and wondering why on earth I was thinking about yellow anything since I'm pretty anti-yellow myself. (The area in question has a variety of (new) martagons that are in the pale yellow to pink range and I realized that I already have committed to some yellow right there.)

In any case, thank you for confirming the plant and your original photographs!

"Hmmm... Kevin, it sounds like you like your plants to stay neatly in defined spaces :-). "

No, not really. I like to use both corydalis as a filler/groundcover too. In this case, the seedlings were growing probably a 1/2 inch or less apart which as you know isn't good for any plant. I should have pulled out lots of 'em, but didn't.

In any case, that was last year. This is a new year. My ultimate goal was to move lots and lots of 'em out of this bed and transplant them in front of a hedge I put in last year. Once there, I hope they cover up all the bare ground. I've found corydalis to be one of the best weed suppressors out there since they grow so dense. Once established around the hedge, they can grow, die, reseed or do whatever they want. I want this area to be very low maintenance.

Kevin

Kevin - I've never bothered thinning out the seedlings and the plants seem to do just fine. It is interesting that they seem to be weed-suppressing but other perennials come up through them without any problem here. Perhaps that's because the other perennials in question are either shade-lovers or spring ephemerals. Weeds that like sun would be shaded out by the dense, relatively tall (~12" or so) growth. They should look good with a hedge - is it an evergreen one? Green and white is my favorite combination :-)

Had Corydalis ochroleuca for several years. It lingered but never really got going. Must be the particular growing conditions.

It may be referred to as short-lived, but as above, many find it a very easy reseeder, like C. lutea.

A presumed example would be the garden at the Manor House, Upton Grey, designed by Gertrude Jekyll in 1908. Jekyll had the area under the peonies carpeted with C. ochroleuca. O. ochroleuca was rediscovered as one of the very few surviving plants in the long abandoned garden in 1984.

I have the yellow in my front garden and the white in my back garden. It was unplanned but works out perfectly, since the front of my house (a row house) is warm tannish brick and the back wall is white. I find that the both kinds seed themselves best where there is fertilizer and moisture (such in as in the pots of container plants). I really like these two charmers. I hardly remember how I got them -- they must have been gifts. They are little blooming machines and the feathery foliage is pretty, too.

woody - The hedge is a privet, so I'm not sure if it will be evergreen in this climate - probably not - although some of the leaves beneath the snow line did stay on this winter.

As to weed suppression, I probably grow my corydalis in more sun than you - at least 1/2 day morning sun - maybe a bit more and where I've noticed it most is where the plants are spaced at least a foot apart so they really have the opportunity to develop into dense, almost bush-like, little things. Nothing seems able to grow through those stems.

monarda - I've noticed with my yellow one (the lutea), its favorite place to reseed successfully is in the little space between my fence and the sidewalk - maybe 1/2 inch wide. I have a whole row of these plants along one section of my fence growing over the sidewalk. They never get watered from me, they survived perfectly through a terrible drought a couple of years ago, so I can only assume the roots like the that concrete covering to keep them moist and cool.

Kevin

Interesting comment on possible microclimates, Kevin.

I have had C. ochroleuca growing in the same spot for many years, could have been as many as ten? I have only managed to salvage a couple of seedlings from it in all that time. I was wondering why everyone else seems to have lots of seedlings, like I do with my C. lutea. I wonder if the fact that it is growing in a bed that used to surround a walnut tree (tree has been cut down for several years, but trunk is still there) has anything to do with basically no seedlings showing up?

For me, I find that here in the PNW it does bloom from April to Nov.

raehelen - That may be the problem. There are some online lists of plants which will not tolerate the toxic affects of walnuts, but I couldn't find corydalis listed as one, but I'm sure these lists are not comprehensive.

I did find this however:

"The black walnut stump will still be creating a toxic environment for all plants that are not tolerant of the chemical (juglone) they introduce to the soil. The toxicity extends well past the year of the treeâÂÂs death and if the stump is allowed to remain, the toxin will still be released into the soil from the degrading root system."

Kevin

While it lived I was prepared to live with it -- what else could I do? -- Robinia pseudoacacia is supposed to be toxic as well to other plants, and I was rejoicing because our new Chinese neighbors took theirs down (the birds plant them in the back yards hereabouts) in a frenzy of remodeling. But the big stump is still there -- a few feet from the property line, encased in concrete. I suppose the toxic roots are also still all over my yard. I have been weeding away suckers from the darn thing for years.

I do worry that without lots of greenery we won't have so many birds. Years ago there were many many more different kinds, including indigo buntings and goldfinches. Alas. Thank God for Green-wood Cemetery, a bird elysium not too distant from here. Well, happily the locusts don't affect corydalis -- to bring things back to the thread -- nor dicentra which romps alongside its smaller cousin (I suppose they are relatives they seem to have so many affinities).

Here is a link that might be useful: Green-wood