I keep all my yellow roses by themselves. They just seem to be incongruous. I have Harison's yellow, rosa foetida lutea, and rosa xanthina on the side, mixed in with red twig dogwood, blue flax, orange poppy, firs, and some leafy spurge that is Montana's most noxious weed that I keep for a pet.
There is one other bush there that blooms yellow that is native whose name I have forgotten. I used to have lupines, silver artemisia, Canterbury bells, and creeping Jenny(yellow) growing there. I've been getting around to doing something with that bed for awhile. The problem is all these roses bloom first, and the flowers come in later. The next rose to bloom is Theresa Bugnet.
In another patch I have Iris and HY. I think they bloom at the same time. I have some scorching yellow Iris, and you have just given me an idea.

Deep blue salvias?
Dark blue or purple Irises?

Both work for me here in somewhat similar conditions, and look compatible with strong yellows (IMHO).

Golden Celebration is here surrounded by a sea of iceplant, which blooms yellow in the spring. But that stuff is a "Devil Plant," and I wouldn't plant it in my worst enemy's garden.

Jeri

I would have white and purple lantanas, lavender scabiosa, lavender plants, Mexican sage (salvia leucantha), irises in different but harmonious colors, white butterfly bushes (buddleia) or any combination thereof. ZD does worry me a bit but I imagine the yellows don't bloom for that long a period anyway and perhaps you can use some of the above plants as a buffer in front of ZD. Another good idea might be senecio or any plant with gray felted leaves to soften the other colors. I think the silver would look great with yellow and the deep pink of ZD.

Ingrid

Well, I don't know. You all may be right. I already have most of the plants you folks list, not growing next to R. foetida but in the garden, and somehow they don't seem right. Blue/violet purple with yellow are supposed to be rich and harmonious, but in this case I doubt that would be the effect--strident is what my mind's eye says; I also doubt the gray-leaved foliage, especially given R. foetida's (as I remember) grass-green foliage. Hmph. I was thinking in terms of lighter but still fresh green foliage, and variagation and flowers of pale acid yellow and greenish white. Or throwing all prudence to the winds and planting orange-red poppies?? I'm not sure whether anything can harmonize with such a color; one's choices are either total submission or open war.

However, I'm not by any means certain of my own ideas. Further suggestions are welcome!

Thanks, all!

Melissa

I vote for poppies and primroses, but what do I know? I live on sandy soil. Bulbs often like dry summers. I have a rosemary plant with yellow varigation on its leaves, but that might be bigger than you'd like, and I don't know how they do on sand. Potentillas perhaps, or geums for all out war.

That should be that I don't know how rosemary does on clay. On sand, they're happy if they aren't in a puddle or pathway.

Jenny,

A YELLOW-VARIEGATED ROSEMARY? I'm swooning! What's its name?

This is the home of rosemary! It grows splendidly in clay if it's on a slope and isn't under a sprinkler, as mine emphatically is not. I have a lot of it, as rosemary's one of the few woody shrubs with dark-green foliage that can handle full sun and alkaline soil, at least, that I've discovered. Rosemary can get large here, but a yellow-variegated form would be worth rerouting the path for.

What kind of primroses are you talking about? I don't think you're referring to members of the genus Primula.

I'm thinking wistfully of columnar herbaceous plants, on rhizomes or simple roots, but with nothing specific in mind. I'm going to take all these various suggestions and go have another look at my rose. Thanks for the ideas.

Melissa

Deep blue salvias, Veronica, muscari spanish bluebells

I was thinking of primulas, my brain went on a minor strike and forgot how much they like water. I was thinking of some of the tall-flowered kind I saw at a nursery here recently that were hot red with a yellow edge? At least that's how my memory goes. And I have a bit of an affair with double-flowered ones, my favorite is Dawn Ansell, and she's a creamy white that would set off any rose; though she probably won't be in bloom at the proper season, now that I'm thinking harder.

The rosemary is Golden Rain, Forestfarm carries it here in the States; I hope you can find it in Italy too. Mine has made a shrub about two to three feet tall in three years, but it's in part shade, not full sun. It's good for flavoring too, I use it more than my others.

A spikey perennial that might work is digitalis lutea, if she can take that much sun and the dry summers. The leaves are narrower and less fuzzy than regular foxgloves, more of a glossy green IIRC, it's been about five years since I left the garden where I grew her.

I'd plant yellow and orange-colored irises, their foliage would look good with foetida's. Daylilies would work as well. I like to take hot-color combinations and make them even hotter. Some kniphophia, some of the euphorbias, etc. Geum and certain poppies, too, along with wallflowers.

--Ron

Hollyhocks. Evening primose as in oenotherea. Penstemons (all sorts). Peopnies if you have room. Whites will soften and cool the look, pinks and blues look like a party, reds and orange look like a fire. Depends on what you want to feel when you look at it. Also, what happens after it's done blooming?

I like all this input: it's very interesting!

The bed is in a field that's being turned into a garden, all set in the middle of the countryside. Therefore it can't look too delicately refined, and companion plants should have a rather rustic meadow-y look; they should also announce their presence in loud confident voices. I haven't gotten out yet for that second look at R. foetida. Today I stopped in at a nursery I'd never visited before, and found yellow-variegated yuccas. Oh, la la! I had been pondering a yucca already. It would take up some space, of course. But. Still. Tempting. (My husband loathes thorny plants, but he DID marry a woman who was in love with roses.)

I think if I were to employ blue and violet they would have to be strong and be dosed out very sparingly, like drops of paint spattered on a predominantly hot-colored canvas. And of course there's the question of timing. Muscari are over, but the classic tall bearded irises are in bloom right now. I wonder if calendulas would work, and soft pink and yellow poppies: just outrageous quantities of color? No harsh, brown-y reddish oranges.

About afterward? There'll be other things going on then. Actually, I haven't thought that far ahead. I rather think that R. foetida blooms and is spectacular, and then you pretty much forget about it until the following spring except admiring any beauties it possesses as a shrub.

Thank you all for the suggestions! I think some of the plants listed are promising.

Melissa