Kipp McMichael
Sun, 30 Dec 2018 22:39:04 PST

  I have R. coulteri growing in my yard in Berkeley where it has not gotten any irrigation since the first 3 years of the clump's life.

  I think Mike is correct - the plants must establish a deep root system for the plant to grow and survive summer. I have observed the plant growing in the multiple California natural areas where it cannot get summer irrigation - so it can survive both drought and high summer temperatures.

  The plant I saw in the wild were small and sparse (5-10 stems < 3ft) compared to the leviathan the plant becomes when well-watered. For me, that was stems 10 feet tall with 100 stems. My front yard does not experience frost so the plant does not experience any winter-setback as it does in places with hard freezes.

From: pbs <> on behalf of Michael Mace <>
Sent: Sunday, December 30, 2018 11:26 AM
Subject: Re: [pbs] Romneya

Leo wrote:

>> As followup, the Matilija poppy (Romneya coulteri) I wrote about in the
fall died within days of being in the 110+ F / 43+C weather, even kept in
the shade and not allowed to go dry. I don't think the Sunset book is
accurate when it says it thrives in All Zones.

For what it's worth, I live in the proper climate for Romneya and struggle
to get it to grow. I think it's very sensitive to soil and watering times.

I planted it in my heavy clay soil and treated like a California native (no
water in summer). It died within a year.

So I planted it in an amended mound with good drainage, and pampered it with
some supplemental water in summer. It died within a year.

Finally in desperation I planted it on a slope in unamended clay soil, next
to a native buckwheat that I planted at the same time. Both plants were
given very occasional water in the first summer (maybe once a month). The
buckwheat thrived, and the Romneya struggled through the first year. Since
then it's been about three years and I haven't given either of them
supplemental water at all. The buckwheat is very happy, and the Romneya is
still alive. It puts up a couple of shoots a year that get about a foot
(.3m) tall. No flowers yet. I figure if I leave it alone maybe it'll
eventually establish itself and take off (I've had other plants do that).

So, it can tolerate dryness all summer when in the ground. But getting it to
thrive, rather than just survive, can be tricky.

I suspect those freeway margins with huge masses of Romneya (some of which
are near my house) are gravelly soil where the plants can establish more

San Jose, CA
(Zone 9, min temp 20F / -7C)

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