a couple promising zone 10 dry garden plants

Centaurea ragusina and Salvia ‘Savannah Blue’ by Native Sons — in my experience, ultimate size is at least double suggested on their website

Domino’s garden in Los Angeles is slowly taking shape, with everyone pitching in to keep it weeded, mulched, and watered while new plants settle in. (We have availed ourselves of mulch from Griffith Park’s generous compost facility, carload after carload, even despite the numerous tree seedlings it includes. Can’t argue with free.)


A couple plants I gambled on have really impressed me. Salvia ‘Savannah Blue’ seemed full of promise in my Long Beach garden but didn’t really get a fair trial, squeezed in among agaves and succulents which it quickly overran. The soil had been serially enriched over the years with compost, and I suspect life might have been a little too easy for this South African hybrid salvia. In Domino’s garden the soil is simply awful, unamended clay, only approachable for planting after a rain, and mercifully there was lots of that last winter to get the garden started. Already I can see the salvia growing much more densely. Reputedly hardy to zone 8, I did try this salvia in Oregon, but fall planting was not a success. It melted away in the rainy winter. But its overall vigor would suggest a spring planting might be successful, if only as a summer annual or protected in a container, and I’m hoping a couple cuttings root to allow for some more experimentation on the rainy Oregon coast.


In Domino’s garden, luxuriating in full sun but somewhat constrained by unamended soil, I feel that this is a fairer trial than I could give this salvia in my crowded Long Beach garden. Finely cut, leathery, scented pelargonium-like leaves, small violet-blue flowers on slim tapers, it’s really shown what it can do here. Healthy, weed-smothering growth. I anticipate this will need a cutback like, say, Salvia leucantha in late winter/spring. It really is unlike any other salvia I’ve grown, with a remarkably good leaf tailor made for a hot dry garden. Along with its small shrubby habit, it strikes me as very worthy of attention, and I’m excited to track how it performs in Domino’s new garden.


But what’s that silver plant? My thoughts exactly when I found it unlabeled at a local nursery. Lacy like the typical dusty miller but with very thick, succulent-like leaves. The subsequent yellow thistle flowers indicate Centaurea ragusina, the Silver Knapweed, endemic to Croatia. Possibly hardy to zone 7, I grabbed a cutting to try in the Oregon garden — in a well-drained container, of course. It’s been around a while, described by Linnaeus in 1753 and mentioned as worthy by William Robinson in the late 1800s, but it seems to have been superseded in the trade by other centaureas/dusty millers. So far it’s kept a compact profile, not a sprawler. A couple friends have grown it and have only nice things to say about this centaurea, apart from it being hard to find.


Personally, I’m a fan of the lemony yellow thistle flowers, in bud or bloom, but do realize that some may prefer to cut them off to showcase its form and leaves — but then you’d be left with a Victorian bedding plant, right? That’s so 19th century…


I do think if you get the chance, that either of these are worth trialing for a zone 8-10 garden on the dry and sunny side. (The centaurea is hardier than the salvia, down to 0° F.)

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7 Responses to a couple promising zone 10 dry garden plants

  1. Gerhard Bock says:

    I’ve been growing Centaurea ragusina (from San Marcos Growers) for a few years now and LOVE IT. Much smaller and less sprawly than the purple Centaurea gymnocarpa (which I do love, but it gets much too big for our garden).

  2. Kris P says:

    I have to find that Salvia. The local garden center chain doesn’t seem to carry Native Sons’ plants often of late, given that they previously had a wide selection. I’ll have to expand my shopping escapades!

  3. hb says:

    I’ve got several of the Centaureas and love it. Best in full full sun–starts to get sprawly as shade increases.

    Saw the Salvia–it looks like a good one–but have not tried it yet. ‘Marine Blue’ seems pretty good. ‘Mystic Spires Blue’ is a favorite of bumble and carpenter bees, so I love it for that, not just for the beauty of the flowers.

  4. I have had zero luck with salvias in Astoria. Per your apt description, despite great progress through summer, they never come back to life the next spring. I’m swearing off them. Now in Los Osos, salvias seem to be super happy. My newly acquired garden has a surfeit of ‘Hot Lips’ (hardly my choice in salvias, but I can’t make changes just yet.)
    I like the look of that Centaurea very much! Could be a great addition to the Astoria garden if I can find it.

  5. Tracy says:

    I think the Centaurea is very pretty, lovely. And nicely paired with that salvia!

  6. Denise Maher says:

    @Gerhard, that’s good to know you’ve grown it longer than a season, thanks!
    @Kris, there may still be some alive in the LB garden, in which case I’ll be happy to share — I’ll check in the fall. It’s a longshot…
    @Jane, agreed, ‘Hot Lips’ is everywhere! I just can’t warm up to it.
    @Tracy, it’s a good silver, a rare one for full sun that doesn’t get too rambunctious.

  7. Jerry says:

    Centaurea ragusina hasn’t been a success in my garden. Did great in the summer heat, hated the winter wet clay and died by spring. I would try again, but in much sharper soil or perhaps underneath the rainshadow of our Dougfirs, on a sunny slope. Gorgeous plant.

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