I call Romneyas "three-in-four" plants --

Three out of four planted die. They're in the same category as Fremontodendron, Trichostema, and a wealth of other such tempermentals.

The good news is, once you have these plants off-and-running, they just go and go and go....with virtually no care.

The trick is to get them started.

First, make sure they're in the best place possible: full sun and perfect drainage. They'll take any kind of soil: clay, rocky, sandy -- as long as it drains well. They're also tolerant of quite a bit of shade with age but I think newbie plants need the sun.

Secondly, what I've found to be a key to successful starting, is to plant the young plants between late November and early February. Then pray for natural rains. With these conditions, the plants put down the best roots and become summer-drought tolerant in their first season. If planted later, you have to deal with the dilemma of giving young plants without a root system enough water yet not so much during the warm summer when root rots become a problem.

And they don't like/need mulch.

Joe

Get rid of the mulch. And they don't like water when getting established. The first time when I tried to start a pot, I watered about once every two weeks. The second time I only watered them when I planted them, then I just forgot about them. That second batch took off that winter (and I planted them in August).

-Ron-

But I love mulch :( how could it ever do harm?

The mulch will encourage rot.

Lots of natives prefer bare mineral soil. Organic material, such as mulch of any kind, can be very detrimental to their well-being.

Back to the Romneya. I have a large clump (5 or 6 yrs. old) in my median strip. Hot baking sun all day, reflected heat from sidewalk and road, no summer water and no mulch amd it's very happy (except for the side that inconsiderate people let their dogs pee on.....but that's another matter).

wanda

I strongly suspect that mulch is mostly a problem in irrigated soil, warm soil and moisture is a major hazard for many native plants (and several mediterranean herbs). Here in Camarillo (soil profiles range from sandy loam to loamy sand on the Oxnard Plain) I mulch even desert cacti without ill effects in a bed that receives no summer irrigation.

As others have noted, time planting for the beginning of the rainy season. Plants that aren't established are a nightmare to keep alive over the summer.

Ryan

I had luck in well drained disturbed soil where cement had been broken up and removed. I planted in the fall before the rain. I watered a little in September and October to keep it from dying (watered as litte as possible) and then it took off will the fall rains.
-Nate

I had to smile when I read Guru's comments about "three in four" plants - Joe, you're right on the money! Except my experience with Fremontodendron is closer to "nine in ten" - I'm about ready to give up.

After trying Romneya once or twice with little success, I bought another one at a Quail Botanic Gardens plant sale in October. I was told that the ONLY time to plant matilijas is in December. Of course that's just folk wisdom, and too sweeping a statement; but it kind of ties into what Joe says. In any case, I tried it, and 15 years later they are running wild in my garden! They're kind of an invasive nuisance, but I can't think of anything more beautiful that I'd like to take over my yard.

My matilijas are on a large slope with echium, agaves, lavateras and acacias; full sun all day, and I do mulch (my own chippings) to keep the weeds down. Everything seems very happy. I don't water that area very much - maybe once a month in the summer; but I find that a little late-spring irrigation extends the bloom on the matilijas for another month or so.

On Al's advice I moved my MPs to a sandy hillside where they do get watered once a week. So far they are thriving... last year they bloomed both spring and fall. They are now reaching for the sky at 6' and rising, and are threatening to become a most beautiful stand.