I don't grow either Crambes since I read that cabbage moth caterpillars can be a problem. If I am going to pick caterpillars, it will be on my broccoli, not my ornamentals. If I am going to grow plants for the caterpillars to eat, it won't be ones I am growing for foliage.

I would be interested in other large-leafed plants for sun you find. Currently the one large-leafed sun plant I have grown successfully has been edible rhubarb which I like all growing season. I let it bloom since I think the flowers are impressive. {{gwi:202959}}From 2013

Rhubarb is definitely on the list - for a pot. I've tried several times and in several locations to get it to grow in the ground here but it just never does well, so I'll try it in a pot to see if that will work.

Good point re insect pests on the Crambe. The C. cordifolia I currently have is out of sight except the flowers, so if the leaves get eaten, I don't notice! But that won't work if I'm growing one for the leaves. I do have a hosta in sun that has done well for two years now so I'll probably try that with a different one that needs dividing because it's too big for its space :-)

No on the Crambe maritima but I've grown Hosta 'Gold Standard' in full sun since 2006. It doesn't grow huge--just a lovely 2 ft.-wide mound near the southeast corner of my house that's been pest- & disease-free the past 8 years. When I think of it (which I sometimes don't), I do sprinkle crushed eggshells around it as it emerges in spring but other than that it's left to its own devices the rest of the growing season. The eggshells discourage slugs/snails.

I do grow Crambe maritima. Foliage is lovely with that amazing glaucous tone and wavy texture. There are lots of little white cabbage butterflies around my garden in the summer but, knock on wood, I have never noticed caterpillars or caterpillar damage on my plant. I do not spray.

If I could criticize anything about the plant, it is that it seemed to take a while to recoup after its glorious late spring flowering. It is as if the plant exhausted itself, even though I promptly trimmed off the spent stems to avoid seed set. Also the foliage can at times be a bit more prostrate than I would like, but no plant is entirely perfect, lol!

I grow mine alongside Campanula 'Sarastro' and Geranium 'Rozanne'. The foliage of the Crambe is the perfect color foil/complement to the violet-blue and purple tones of its companions.

What kind of soil do you have? How moist/dry is it?

I have mainly well-drained sandy loam. I usually water (with a hose) quite a bit during the summer since my soil dries so fast. I think Crambe maritima is supposed to be quite drought tolerant.

eryngium 'Silver Ghost, although a biennial, is noted for glaucous foliage (along with quite a few interesting eryngoes).... when crambe grows in its native coastal positions, it is stunning....and also grows well with eryngium maritima and lavatera maritima.
Looks fabulous with California poppies and sphaeralceas in gravel.

Oh yeah, now I am thinking about it - if you like tall airy plants, take a look at the amazing althea cannabina - 6 foot of dainty deliciousness.

I have tried and tried to get Eryngium 'Silver Ghost' and cream-colored California poppies established in my garden, but no success for me so far! The eryngium (from purchased transplants) will live and flower, and then I look for any seed formed to scatter around. I have not found a single seedling yet. And the California poppies will germinate for me and then sit there and remain stunted at 2 inches tall. Dill will do the same for me. I have no idea why?

Another favorite plant that has some purply, almost glaucous tones is Artemisia lactiflora 'Guizhou'. Gorgeous tall but narrow plant with lovely ferny-textured foliage and tall airy spikes of creamy white flowers that hover like a mist for months and months. A similar effect to thalictrum. Artemisia lactiflora is different from other artemisias in that it is a clumper--no ambition to take over the world with this one--and needs moist soil. So far, I love mine!

"6 foot of dainty deliciousness."
Sets a new standard, in men and in plants. Campanula, you do have a way with words.

Eryngiums of any sort have never done very well here. I Googled Althea cannabina and only seemed to find European/UK sites for it, so I doubt I'd find a source for that. Google images for Crambe maritima are quite variable - I'm guessing that the really good-looking ones must be ones in environments similar to their native ones - which my location definitely is not! :-) I have a Artemisia lactiflora 'Guizhou' that sort of languishes, but hasn't yet died, in less than ideal conditions at the back of the main front garden bed!

What I'm really looking for is something for sun with the big-leafed-look of hostas - which is one of the reasons rhubarb would be ideal IF I could get it to grow in the ground out there! I will try a division of a nice bright grass-green hosta from the backyard and see how it does. I know the yellow-green hostas are usually reasonably sun-tolerant but they're not the right color for the front bed. The hosta that has done reasonably well out there for the last two years is a big blue one.

Can anyone think of anything else sun-loving/tolerant with the look of rhubarb or hosta leaves?

shame - i can send you seeds (for althea cannabina) this year if you want, Woody (it's very easy from seed).

astilboides tabularis - likes a bit of shade but will grow in a south facing aspect with enough moisture.
Gunnera manicata - an obvious choice
rogersia pinnata (although I find this, and ligularias tricky in my dry soil)
fatsia japonica and related fatshedera lizei - both will do OK in sun although they are commonly used a shade plants
Salvia argentea - amazing white huge hairy leaves - a biennial but easy from seed
various verbascums

campanula - astilboides I have and love! But it needs lots of water - the ones in the north alley that get water from the downspouts from the eaves thrive; those elsewhere are pathetic! They would definitely not do well in my sunny, hot, dry, heavy soil in the front garden! Gunnera and fatsia - not hardy here at all. Rodgersia I like; I grow R. aesculifolia because I like their leaf shape best. The best-looking and biggest ones are in the most shade and the couple in the front garden in the bed along the garage don't do nearly as well, so I'm sure they'd not be at all happy in more sun. The Salvia argentea is exactly the sort of look I'm after! It might not be happy in the heavy soil in the front garden and I'll have to think about whether I want to try it as an annual (which is likely what it'd be here....) Verbascum - are you thinking of the big silvery one with the yellow flower spikes? I think that is grown in gardens in the UK - here it is a weed! People would think I'd lost control of the garden if I planted that one :-)

Thanks for the offer of seeds of the althea cannabina - tell me more about it... (I'm wary of the mallow family as I'm still trying to rid myself of seedlings of one I planted - and removed - more than 10 years ago! I'm rigorous about removing seed capsules from hardy hibiscuses for fear of them running rampant. Hollyhocks, on the other hand, seeded moderately and died out easily when I evicted them for too much rust!) So how well-behaved is that one re seeding?

Salvia argentea is one I have grown. I planted it in the sunny, gravelly-soiled garden next to the path to the main house door. It looks striking, with slightly furry silvery-white leaves, and was hardy here. The blooms were airy and pretty, but it didn't seed itself. My one problem with it is the smell, which I found pretty unpleasant (kind of eau de old cat litter), and noticeable from the walkway several feet away from the plant. I would definitely plant this one again, but I would not put it where it would be near a walkway or an open window.

:-) good warning re the scent!

You could look at clary sage (s. Sclarea) too, not as grey a leaf and also more biennial but I think more tolerant of so-so drainage.
Don't write off the verbascum too quickly! Its not as easy to find but verbascum bombyciferum has a white-grey foliage and stem with bright yellow blooms. Very cool, Tall though.

yep, V.bombyciferum or V.olympicum are thrilling plants and nicer than the common Aaron's rod (V.thapsis).

Mallows- yes, the bane of my life on the allotment - roots which go down to Australia and a tendency to plant themselves in the very centre of treasured perennials. A,cannabinoides will also seed about....but nothing like the common mallow sylvestris and is easier to fork out if you have enough. Mostly, I got it because I was fed up with the ubiquitous (and seedy) verbena bonariensis - needing a large airy see through plant.

As nice as the 'fancy' verbascums appear to be, they still look too much like the weedy ones around here so I just can't see myself adding those to the garden :-)

campanula - do you have some pictures of your A. cannabinoides - there are very few when I do a Google search.... What color(s) are the flowers? Are the leaves susceptible to rust like hollyhocks? Does it have preferences for soil type/moisture levels? Is it perennial? Malva sylvestris - yep! That's the one that is still appearing 10 years after digging it out. Malva moschata is a PITA too, but a somewhat smaller one.... If I do conclude the A. cannabinoides is worth risking :-) are there any seeds I could offer you in trade? Some of my pink hardy hibiscuses perhaps....?

Although lovely and also one I would grow again, I find clary sage has the same odor issue as S. argentea. I have grown some of the garden varieties of Verbascum, perhaps hybrids(?), and wasn't all that impressed, though it may have been the varieties I had. Leaves weren't as large or ornamental as S. argetea and the flower colors were hard to match: salmon and a light purplish red. They weren't as impressive as V. olympicum or V. bombyciferum, but they would fit into a suburban garden better. Perhaps hybrid Verbascums have improved in the 10 years or so since I tried them and would be worth looking at. They had medium-large slightly fuzzy leaves and tidy flower spikes a bit like larkspurs, though not in the same color range.

Um, you are quite correct NHBabs, in saying some of the verbascums are a bit....naff, especially the seedgrown strains such as Southern Charm- measly little things with nothing of the grace and stature of Cotswold Cream, V.chaixii or even the seed raised V.phoenicum (I have a little purple one from a strain called 'Violetta')....and there is always the threat of mullein moth to contend with....but for all that, they are a nice easy early summer addition around roses and hardy geraniums and foxgloves.
There has been a pernicious movement in the UK towards dwarf plants - 'compact', 'tiny' and 'neat' have been major selling points, often retaining full size flowers on dwarfish plants. The horror of Campanula lactiflora 'pouffe' springs to mind here - a plant I would defintely trample underfoot in disdain. I know we have small gardens in the UK (so get to grips with alpines!) but this whole shrinking thing is quite horrible.
Woody, althea cannabinoides has many many small (2inch) pink flowers with darker centres, growing in the leaf axils. The leaves are almost invisible, very thin (like cannabis sativa leaves) and not susceptible to rust. The whole thing is very reminiscent of a crambe inasmuch as the tall plant throws out sprays of blooming branches and does well in poor sunny soil (the sort you would use for nasturtiums)....in a wilder part of the garden. Will take pics when mine flowers, which will also be when I collect seeds - no need for swaps although I am always up to try something different from your side of the world.

campanula - that sounds like it should be interesting to try so I'd be happy to get some seeds... (you can e-mail me through the 'my page' link - I think it still works... - to arrange details when the seeds are ready.) When does it bloom? What sort of plants interest you in particular so I can think about what seeds might be available that would interest you.

Not perhaps THE largest leaves but still somewhat broad: Phlomis russeliana, Inula helenium, Limonium latifolium (Crambe-esque look to it).

I was also going to suggest Acanthus, Comfrey, and Macleaya cordata, but I seem to recall you steer clear of possible runners in your garden?

Also assuming you want perennial and not annual/tropical?
CMK

CMK - yes, I try to avoid anything that runs or seeds aggressively. The Limonium latifolium looks interesting although from what I can see by Googling, the leaves are relatively small. But it otherwise looks like something that would suit the garden here, so I'll add that to the shopping list :-)

How about Rumex? I have considered it for foliage plant. Never tried it though.

I have battled too many weeds from that family to voluntarily add one unless someone very reliable vouches for it being well-behaved :-). Is there a particular species you are suggesting?

I was recently reminded of variegated comfrey, Symphytum x uplandicum 'Axminster Gold' by an email from a favorite nursery. It has nice large leaves with a bold cream edge and a rough texture. I haven't grown the variegated type, though I hear it is less aggressive than the all-green plants. If I were to plant this, I think I would plant it in a bottomless container such as a clay chimney tile. Perhaps someone else who has grown it can weigh in on whether it is less spreading, and if a container will actually contain it. My memory was that the spreading was solely via rhizomes, but I am not entirely sure of that.

Nhbabs, I grow Symphytum 'Axminster Gold'. So far, it has been a very well behaved clumper with absolutely no signs of spreading rhizomes. I don't think you would need to contain it in any special way. It is a very pretty and eye-catching plant, and definitely seems to appreciate supplemental feeding with organic nutrients throughout the growing season.